Download Hi-Res Image 下载高分辨率图像Download to MS-PowerPoint
下载到 MS-PowerPointCite This: 引用以下内容：Environ. Sci. Technol. Lett.
环境。Sci. Technol. Lett. 2024, XXXX ，XXXX, XXX 、XXX, XXX-XXX 、XXX-XXX系列
下载到 MS-PowerPointCite This: 引用以下内容：Environ. Sci. Technol. Lett.
环境。Sci. Technol. Lett. 2024, XXXX ，XXXX, XXX 、XXX, XXX-XXX 、XXX-XXX系列
How Do Metal Oxides Mislead Spin-Trapping Electron Paramagnetic Resonance Analysis?
金属氧化物如何误导自旋捕获电子顺磁共振分析？IF 10.9SCIEJCI 1.42Q1环境科学与生态学2区
- Jing-Hang Wu 吴静航Jing-Hang WuCAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, ChinaMore by Jing-Hang Wu
- and
- Han-Qing Yu* 于寒青*Han-Qing Yu 俞寒青*Email: hqyu@ustc.edu.cn *电子邮件：hqyu@ustc.edu.cnCAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
中国科学技术大学环境科学与工程系， 中国科学院城市污染物转化重点实验室， 安徽 合肥230026More by Han-Qing Yu 更多Han-Qing Yu的产品
Cite this: Environ. Sci. Technol. Lett. 2024, XXXX, XXX, XXX-XXX
引用： Environ.Sci. Technol. Lett.2024， XXXX， XXX， XXX-XXX
引用： Environ.Sci. Technol. Lett.2024， XXXX， XXX， XXX-XXX
© 2024 American Chemical Society
© 2024 美国化学学会
© 2024 美国化学学会
Your access to this publication has been provided by RES CENTER OF ECO ENVIR SCILearn More
Abstract 抽象
Limited by the detection techniques, the reactive species involved in catalytic water purification processes are difficult to be clarified. Spin-trapping electron paramagnetic resonance (EPR) analysis is recognized as a reliable tool for radical identification, in which 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) is usually used as the radical trapper. However, it is questioned that the detection of adducts of DMPO definitively indicates the generation of radicals. In this work, the DMPO transformation caused by transition metal oxides is monitored by EPR, and abundant spin signals are observed. MnO2, Mn2O3, and NiO could oxidize DMPO into DMPOX through direct oxygen transfer. Besides, the dissolved transition metal ions could transform DMPO into misleading DMPO–OH and DMPO–R. The findings in this work, e.g., the interactions between DMPO and different metal oxides and the quenching behavior of the different pathways, would help with reliable identifications of reactive species in both engineered systems and natural environments.
受制于检测技术，催化水净化过程中涉及的反应性物质难以明确。自旋捕获电子顺磁共振（EPR）分析被认为是自由基鉴定的可靠工具，其中5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）通常用作自由基捕获器。然而，对DMPO加合物的检测明确表明自由基的产生受到质疑。本文通过EPR监测过渡金属氧化物引起的DMPO转变，并观察到丰富的自旋信号。MnO 2 、MnO 2 3 和NiO可以通过直接的氧转移将DMPO氧化成DMPO。此外，溶解的过渡金属离子可以将DMPO转化为误导性的DMPO-OH和DMPO-R。这项工作的发现，例如DMPO与不同金属氧化物之间的相互作用以及不同途径的淬灭行为，将有助于可靠地鉴定工程系统和自然环境中的反应性物质。
This publication is licensed under the terms of your
institutional subscription.
Request reuse permissions.
本出版物根据机构订阅条款获得许可。请求重用权限。
Introduction 介绍
Oxidative radicals play pivotal roles in various environmental processes, including geochemical cycles and the natural degradation of pollutants. (1,2) This significance is further underscored by their increasing utilization in engineered catalytic oxidation processes for water treatment. (3,4) Conventional techniques for detecting these transient, highly reactive radicals include (i) probes, (ii) quenching experiments, and (iii) spin-trapping electron paramagnetic resonance (EPR) analysis. (5,6) However, as the recognition of oxidative species broadens, the selectivity and dependability of both radical probes and quenching experiments have been extensively questioned. (7−9) For instance, false positives have been observed in the spin-trapping processes for identifying singlet oxygen (1O2), which could be distinguished by in situ kinetic EPR analysis. (10) Nevertheless, when identifying radicals, typically using 5-dimethyl-1-pyrroline-N-oxide (DMPO) as a trapper, a comprehensive understanding of potential false positives has not yet been completely achieved.
氧化自由基在各种环境过程中起着举足轻重的作用，包括地球化学循环和污染物的自然降解。（1,2）它们在工程催化氧化工艺中越来越多地用于水处理，进一步强调了这一重要性。（3,4）检测这些瞬态高反应性自由基的常规技术包括（i）探针，（ii）淬灭实验和（iii）自旋捕获电子顺磁共振（EPR）分析。（5,6） 然而，随着对氧化物质的识别范围的扩大，自由基探针和淬灭实验的选择性和可靠性受到广泛质疑。（7−9） 例如，在识别单线态氧 （ 1 O 2 ） 的自旋捕获过程中观察到假阳性，这可以通过原位动力学 EPR 分析来区分。（10）然而，在识别自由基时，通常使用5-二甲基-1-吡咯啉-N-氧化物（DMPO）作为捕获器，尚未完全实现对潜在假阳性的全面了解。
氧化自由基在各种环境过程中起着举足轻重的作用，包括地球化学循环和污染物的自然降解。（1,2）它们在工程催化氧化工艺中越来越多地用于水处理，进一步强调了这一重要性。（3,4）检测这些瞬态高反应性自由基的常规技术包括（i）探针，（ii）淬灭实验和（iii）自旋捕获电子顺磁共振（EPR）分析。（5,6） 然而，随着对氧化物质的识别范围的扩大，自由基探针和淬灭实验的选择性和可靠性受到广泛质疑。（7−9） 例如，在识别单线态氧 （ 1 O 2 ） 的自旋捕获过程中观察到假阳性，这可以通过原位动力学 EPR 分析来区分。（10）然而，在识别自由基时，通常使用5-二甲基-1-吡咯啉-N-氧化物（DMPO）作为捕获器，尚未完全实现对潜在假阳性的全面了解。
DMPO-radical adducts are reported to produce characteristic EPR signals that facilitate the sensitive identification of radicals from EPR spectra. (11) However, a false DMPO–OH signal has been demonstrated to be originated from direct oxidation in electrocatalytic process. (12) In addition, the DMPO–OH formation caused by the nucleophilic dosing of water to DMPO has been observed in the presence of transition metal ions such as Cu2+ and Fe3+. (13,14) These ions are well-known for catalyzing the oxidation of organic compounds by peroxides, leading to Fenton and Fenton-like reactions. (15−18) Consequently, as transition metal-based heterogeneous catalysts are developed for radical-dominant catalytic oxidation processes, (19−21) the possibility of nonradical transformations of DMPO warrants investigations. Given the tendency of metal ions to dissolve into aqueous environments from solid phases, (22,23) we propose that nanomaterials containing transition metals could be significant sources of unrecognized false-positive EPR signals in radical identification. If confirmed, the current understanding of catalytic oxidation mechanisms might be partially misled.
据报道，DMPO 自由基加合物可产生特征性 EPR 信号，有助于从 EPR 谱图中灵敏地鉴定自由基。（11） 然而，错误的 DMPO-OH 信号已被证明是源于电催化过程中的直接氧化。（12）此外，在Cu 2+ 和Fe等过渡金属离子存在下，还观察到水对DMPO的亲核加量引起的DMPO-OH形成 3+ 。（13,14） 众所周知，这些离子通过过氧化物催化有机化合物的氧化，导致芬顿和芬顿样反应。（15−18）因此，随着过渡金属基非均相催化剂被开发用于自由基主导的催化氧化过程，（19−21）DMPO非自由基转化的可能性值得研究。鉴于金属离子从固相溶解到水环境中的趋势，（22,23）我们提出，含有过渡金属的纳米材料可能是自由基鉴定中未识别的假阳性EPR信号的重要来源。如果得到证实，目前对催化氧化机制的理解可能会被部分误导。
据报道，DMPO 自由基加合物可产生特征性 EPR 信号，有助于从 EPR 谱图中灵敏地鉴定自由基。（11） 然而，错误的 DMPO-OH 信号已被证明是源于电催化过程中的直接氧化。（12）此外，在Cu 2+ 和Fe等过渡金属离子存在下，还观察到水对DMPO的亲核加量引起的DMPO-OH形成 3+ 。（13,14） 众所周知，这些离子通过过氧化物催化有机化合物的氧化，导致芬顿和芬顿样反应。（15−18）因此，随着过渡金属基非均相催化剂被开发用于自由基主导的催化氧化过程，（19−21）DMPO非自由基转化的可能性值得研究。鉴于金属离子从固相溶解到水环境中的趋势，（22,23）我们提出，含有过渡金属的纳米材料可能是自由基鉴定中未识别的假阳性EPR信号的重要来源。如果得到证实，目前对催化氧化机制的理解可能会被部分误导。
In this work, we examined the EPR response of DMPO in the suspensions of different commercially available nanosized metal oxides (MOs). Herein, we uncovered two distinct pathways of DMPO transformations, i.e., on the surface and in the solution, and revealed the effects of solution conditions and quenching strategies on these unexpected DMPO transformations. Our findings highlighted the urgent need to recognize transition metal species as potential contributors to spin-trapping signals in EPR studies, thereby necessitating methodology refinements in exploring catalytic oxidation system mechanisms.
在这项工作中，我们研究了DMPO在不同市售纳米金属氧化物（MOs）悬浮液中的EPR响应。本文揭示了DMPO转化的两种不同途径，即表面和溶液中，并揭示了溶液条件和淬灭策略对这些意想不到的DMPO转化的影响。我们的研究结果强调了迫切需要在EPR研究中认识到过渡金属物种是自旋捕获信号的潜在贡献者，因此有必要在探索催化氧化系统机制时改进方法。
在这项工作中，我们研究了DMPO在不同市售纳米金属氧化物（MOs）悬浮液中的EPR响应。本文揭示了DMPO转化的两种不同途径，即表面和溶液中，并揭示了溶液条件和淬灭策略对这些意想不到的DMPO转化的影响。我们的研究结果强调了迫切需要在EPR研究中认识到过渡金属物种是自旋捕获信号的潜在贡献者，因此有必要在探索催化氧化系统机制时改进方法。
Methods and Materials 方法和材料
Materials 材料
All reagents, including buffers, MOs (i.e., MnO2, Mn2O3, MnO, Fe2O3, Fe3O4, NiO, CuO, Cu2O, and Co3O4), alcohols, and other organics used in this work, were purchased from Aladdin Reagent Co., China. The spin trapper DMPO was purchased from DOJINDO Molecular Technologies, Inc., China.
所有试剂，包括缓冲液、MO（即 MnO 2 、Mn 2 O 3 、MnO、Fe 2 3 O、Fe 3 O 4 、NiO、CuO、Cu 2 O 和 Co 3 O 4 ）、醇和本工作中使用的其他有机物，均购自中国阿拉丁试剂有限公司。自旋捕集器DMPO购自中国DOJINDO Molecular Technologies， Inc.。
所有试剂，包括缓冲液、MO（即 MnO 2 、Mn 2 O 3 、MnO、Fe 2 3 O、Fe 3 O 4 、NiO、CuO、Cu 2 O 和 Co 3 O 4 ）、醇和本工作中使用的其他有机物，均购自中国阿拉丁试剂有限公司。自旋捕集器DMPO购自中国DOJINDO Molecular Technologies， Inc.。
Experimental Procedures 实验程序
To explore the transformation of DMPO in the presence of various MOs, we directly measured the EPR responses of their mixtures. The MOs were suspended in different solutions with or without organic quenchers. After ultrasonic dispersion, the MO suspension was mixed with the DMPO solution in a 2 mL vial and immediately transferred into an EPR capillary tube (1 mm inner diameter). This tube was immediately placed into the cavity of an EPR spectrometer for spectra acquisition. To obtain MO-free filtrates, the suspensions were filtered using a 0.22-μm polytetrafluoroethylene syringe filter.
为了探索DMPO在各种MO存在下的转变，我们直接测量了其混合物的EPR响应。将MO悬浮在含有或不含有机淬灭剂的不同溶液中。超声分散后，将MO悬浮液与DMPO溶液混合在2 mL小瓶中，并立即转移到EPR毛细管（内径1 mm）中。该试管立即放入EPR光谱仪的腔中进行光谱采集。为了获得无MO滤液，使用0.22μm聚四氟乙烯针头过滤器过滤悬浮液。
为了探索DMPO在各种MO存在下的转变，我们直接测量了其混合物的EPR响应。将MO悬浮在含有或不含有机淬灭剂的不同溶液中。超声分散后，将MO悬浮液与DMPO溶液混合在2 mL小瓶中，并立即转移到EPR毛细管（内径1 mm）中。该试管立即放入EPR光谱仪的腔中进行光谱采集。为了获得无MO滤液，使用0.22μm聚四氟乙烯针头过滤器过滤悬浮液。
EPR Analysis 生产者责任延伸分析
The EPR spectra were acquired by an EPR spectrometer (EMX Plus, Bruker Co., Germany). The modulation amplitude, microwave power, and microwave frequency were set at 2.0 G, 2.0 mW, and 9.8422 GHz, respectively. Spectral simulations were performed in Matlab 2022b (Mathworks) with an Easyspin 5.2.35 toolkit (Text S2). (24)
EPR光谱由EPR光谱仪（EMX Plus，Bruker Co.，Germany）获取。调制幅度、微波功率和微波频率分别设定为2.0 G、2.0 mW和9.8422 GHz。在 Matlab 2022b （Mathworks） 中使用 Easyspin 5.2.35 工具包（文本 S2）进行频谱模拟。(24)
EPR光谱由EPR光谱仪（EMX Plus，Bruker Co.，Germany）获取。调制幅度、微波功率和微波频率分别设定为2.0 G、2.0 mW和9.8422 GHz。在 Matlab 2022b （Mathworks） 中使用 Easyspin 5.2.35 工具包（文本 S2）进行频谱模拟。(24)
Results and Discussion 结果与讨论
Reactions between DMPO and MOs
DMPO和MO之间的反应
Oxidants commonly used in catalytic systems, such as peroxymonosulfate (PMS), peroxydisulfate (PDS), and peracetic acid (PAA), were found to affect the solution pH (Table S1), thus potentially promoting metal dissolution. To examine the radical-independent transformation of DMPO in the presence of metal oxide MOs in actual catalytic systems, we acquired the EPR spectra both at pH 7.0 and at pH 3.0 (Figure 1a). The results reveal a pronounced effect of aqueous acidity on the DMPO transformation, raising concerns that misleading EPR signals might predominantly occur in such acidic systems.
催化体系中常用的氧化剂，如过氧单硫酸盐（PMS）、过氧二硫酸盐（PDS）和过氧乙酸（PAA），被发现会影响溶液的pH值（表S1），从而可能促进金属溶解。为了研究在实际催化系统中金属氧化物MO存在下DMPO的自由基非依赖性转变，我们获得了pH 7.0和pH 3.0下的EPR谱图（图1a）。结果揭示了水性酸度对DMPO转化的显着影响，这引起了人们的担忧，即误导性的EPR信号可能主要发生在这种酸性系统中。
催化体系中常用的氧化剂，如过氧单硫酸盐（PMS）、过氧二硫酸盐（PDS）和过氧乙酸（PAA），被发现会影响溶液的pH值（表S1），从而可能促进金属溶解。为了研究在实际催化系统中金属氧化物MO存在下DMPO的自由基非依赖性转变，我们获得了pH 7.0和pH 3.0下的EPR谱图（图1a）。结果揭示了水性酸度对DMPO转化的显着影响，这引起了人们的担忧，即误导性的EPR信号可能主要发生在这种酸性系统中。
Figure 1 图1
Figure 1. (a) EPR spectra of DMPO-trapping products in the MO suspensions and the corresponding filtrates. (b) Two pathways for DMPO transformation. (c) The effects of different buffers on the DMPO-trapping products in the presence of MOs. (d) The experimental and simulated EPR spectra of DMPO in the presence of copper oxides (i.e., CuO and Cu2O). (e) First-order mass spectra (inner) and second-order mass spectra for product identification of DMPO–R using LC-MS/MS analysis. Conditions: [DMPO] = 100 mM, [metal oxides] = 1 g·L–1, [buffers] = 10 mM. “Blank” denotes samples solely containing MO and DMPO.
图 1.（a） MO悬浮液和相应滤液中DMPO捕获产物的EPR谱图。（b） DMPO转化的两种途径。（c） 在存在MOs的情况下，不同缓冲液对DMPO捕获产物的影响。 （d） DMPO在氧化铜（即CuO和Cu 2 O）存在下的实验和模拟EPR谱图。（e） 使用LC-MS/MS分析对DMPO-R进行产物鉴定的一阶质谱（内部）和二阶质谱。条件：[DMPO]=100 mM，[金属氧化物]=1 g·L –1 ，[缓冲液]=10mM。“空白”表示仅含有 MO 和 DMPO 的样品。
More specifically, MnO2 and Mn2O3 could directly oxidize DMPO to 5,5-dimethyl-1-pyrrolidone-N-oxyl (DMPOX) at low pHs, (25) while NiO-induced DMPOX generation could be feasible at neutral pH but was slightly suppressed as pH increased. Notably, the NiO filtrate could not catalyze the transformation of DMPO into DMPOX, indicating that DMPO oxidation relied on the MO surfaces. Conversely, suspensions of Fe2O3, Fe3O4, CuO, and Cu2O exhibited similar behaviors on DMPO transformation with the corresponding filtrates, mainly generating DMPO–OH and DMPO–R (addition product of DMPO by carbon-centered radical). (26) Therefore, their formations were mediated by dissolved metal ions.
更具体地说，MnO 2 和 Mn 2 O 3 可以在低 pH 值下直接将 DMPO 氧化为 5,5-二甲基-1-吡咯烷酮-N-氧基 （DMPOX） （25），而 NiO 诱导的 DMPOX 生成在中性 pH 值下是可行的，但随着 pH 值的增加而略微抑制。值得注意的是，NiO滤液不能催化DMPO转化为DMPO，表明DMPO氧化依赖于MO表面。相反，Fe 2 O 3 、Fe 3 O 4 、CuO和Cu 2 O的悬浮液在DMPO转化过程中表现出相似的行为，主要生成DMPO-OH和DMPO-R（碳心自由基对DMPO的加成产物）。（26）因此，它们的形成是由溶解的金属离子介导的。
更具体地说，MnO 2 和 Mn 2 O 3 可以在低 pH 值下直接将 DMPO 氧化为 5,5-二甲基-1-吡咯烷酮-N-氧基 （DMPOX） （25），而 NiO 诱导的 DMPOX 生成在中性 pH 值下是可行的，但随着 pH 值的增加而略微抑制。值得注意的是，NiO滤液不能催化DMPO转化为DMPO，表明DMPO氧化依赖于MO表面。相反，Fe 2 O 3 、Fe 3 O 4 、CuO和Cu 2 O的悬浮液在DMPO转化过程中表现出相似的行为，主要生成DMPO-OH和DMPO-R（碳心自由基对DMPO的加成产物）。（26）因此，它们的形成是由溶解的金属离子介导的。
Subsequently, distinct transformation pathways of DMPO in the presence of MOs were identified (Figure 1b). Pathway I involved the direct oxidation of DMPO into DMPOX via an oxygen atom transfer mechanism. Such a DMPOX generation has been previously attributed to 1O2, excess HO•, and high-valent metal species. (27−30) However, the direct DMPO transformation without oxidant on the MO surfaces has received little attention. (31,32) Moreover, the direct oxygen transfer process on the MO surfaces might be the initial step of the catalytic cycle for oxidative metal species-dominated oxidation of organic pollutants. Pathway II enabled MOs to transform DMPO into EPR-active adducts through dissolved metal ions, which could also contribute to the homogeneous catalytic oxidation processes. Interestingly, in CuO suspensions, the coexistence of these two pathways was observed. At neutral pH, DMPO was directly oxidized, while at a lower pH (<3.0), an increase in dissolved Cu2+ dominated the DMPO transformation to DMPO–OH and DMPO–R. Moreover, after dosing the metal ions at the detected concentration, we facilitated the reoccurrence of the EPR signals (Figure S1), demonstrating that Pathway II was mediated by the dissolved metal ions.
随后，确定了存在MO的DMPO的不同转化途径（图1b）。途径 I 涉及通过氧原子转移机制将 DMPO 直接氧化为 DMPOX。这种DMPOX的产生以前被归因于 1 O 2 、过量的 • HO和高价金属物种。（27−30）然而，在MO表面不使用氧化剂的直接DMPO转化很少受到关注。（31,32） 此外，MO表面的直接氧转移过程可能是氧化金属物种主导的有机污染物氧化催化循环的第一步。通路II使MOs能够通过溶解的金属离子将DMPO转化为EPR活性加合物，这也有助于均匀的催化氧化过程。有趣的是，在CuO悬浮液中，观察到这两种途径的共存。在中性pH值下，DMPO被直接氧化，而在较低的pH值（<3.0）下，溶解Cu的增加 2+ 主导了DMPO向DMPO-OH和DMPO-R的转化。此外，在以检测到的浓度加药金属离子后，我们促进了 EPR 信号的再次出现（图 S1），表明通路 II 是由溶解的金属离子介导的。
随后，确定了存在MO的DMPO的不同转化途径（图1b）。途径 I 涉及通过氧原子转移机制将 DMPO 直接氧化为 DMPOX。这种DMPOX的产生以前被归因于 1 O 2 、过量的 • HO和高价金属物种。（27−30）然而，在MO表面不使用氧化剂的直接DMPO转化很少受到关注。（31,32） 此外，MO表面的直接氧转移过程可能是氧化金属物种主导的有机污染物氧化催化循环的第一步。通路II使MOs能够通过溶解的金属离子将DMPO转化为EPR活性加合物，这也有助于均匀的催化氧化过程。有趣的是，在CuO悬浮液中，观察到这两种途径的共存。在中性pH值下，DMPO被直接氧化，而在较低的pH值（<3.0）下，溶解Cu的增加 2+ 主导了DMPO向DMPO-OH和DMPO-R的转化。此外，在以检测到的浓度加药金属离子后，我们促进了 EPR 信号的再次出现（图 S1），表明通路 II 是由溶解的金属离子介导的。
Effects of Buffer and pH on DMPO Transformation
缓冲液和pH值对DMPO转化的影响
Buffers are frequently utilized to stabilize pH levels in the exploration of catalytic oxidation mechanisms. However, these buffers could interact with the dominate oxidative species or activate the oxidants through different pathways. (33−36) In addition, these buffers could alter the solubility equilibrium of metal ions in MO suspensions, which might further change the transformation pathway of DMPO. Thus, we examined the effects of different buffers, including acetate buffer solution (ABS, pH 4.00), potassium hydrogen phthalate (KHP, pH 4.01), phosphate buffer solution (PBS, pH 6.86), and borate buffer solution (BBS, pH 9.18), on the DMPO-trapping signals (Figure 1c).
缓冲液经常用于稳定催化氧化机制的pH值。然而，这些缓冲液可以与主要氧化物种相互作用或通过不同的途径激活氧化剂。（33−36）此外，这些缓冲液还能改变金属离子在MO悬浮液中的溶解度平衡，从而进一步改变DMPO的转化途径。因此，我们检查了不同缓冲液的影响，包括乙酸盐缓冲溶液（ABS，pH 4.00）、邻苯二甲酸氢钾（KHP，pH 4.01）、磷酸盐缓冲溶液（PBS，pH 6.86）和硼酸盐缓冲溶液（BBS，pH 9.18），对DMPO捕获信号的影响（图1c）。
缓冲液经常用于稳定催化氧化机制的pH值。然而，这些缓冲液可以与主要氧化物种相互作用或通过不同的途径激活氧化剂。（33−36）此外，这些缓冲液还能改变金属离子在MO悬浮液中的溶解度平衡，从而进一步改变DMPO的转化途径。因此，我们检查了不同缓冲液的影响，包括乙酸盐缓冲溶液（ABS，pH 4.00）、邻苯二甲酸氢钾（KHP，pH 4.01）、磷酸盐缓冲溶液（PBS，pH 6.86）和硼酸盐缓冲溶液（BBS，pH 9.18），对DMPO捕获信号的影响（图1c）。
In high-pH buffers, such as PBS and BBS, the formation of DMPOX on MnO2 and Mn2O3 was completely inhibited. Such a suppression was consistent across acetate- and phosphate-buffered solutions at different pH levels (Figure S3), indicating a pH dependency of the direct oxygen atom transfer reactions. (37) Nevertheless, DMPOX generation on NiO was partially inhibited by PBS and BBS, yet remained unaffected by pH changes from 3.0 to 8.0 within individual buffer systems or an unbuffered system (Figure S4). These results suggest the broader formations for NiO-induced DMPOX generation in spin-trapping EPR analysis, which might be ascribed to the mechanism difference with MnxOy-induced DMPOX generation (Text S6). Also, interactions between the buffers and MOs, rather than pH variations alone, primarily affected DMPOX formation.
在PBS和BBS等高pH缓冲液中，完全抑制了MnO 2 和MnO 2 3 上DMPOX的形成。在不同pH值下，这种抑制在醋酸盐和磷酸盐缓冲溶液中是一致的（图S3），表明直接氧原子转移反应的pH依赖性。（37） 然而，PBS 和 BBS 部分抑制了 NiO 上 DMPOX 的产生，但不受单个缓冲系统或无缓冲系统中 pH 值从 3.0 到 8.0 变化的影响（图 S4）。这些结果表明，在自旋捕获 EPR 分析中，NiO 诱导的 DMPOX 生成的形成范围更广，这可能归因于与 Mn x O y 诱导的 DMPOX 生成的机制差异（文本 S6）。此外，缓冲液和 MO 之间的相互作用，而不是单独的 pH 值变化，主要影响了 DMPOX 的形成。
在PBS和BBS等高pH缓冲液中，完全抑制了MnO 2 和MnO 2 3 上DMPOX的形成。在不同pH值下，这种抑制在醋酸盐和磷酸盐缓冲溶液中是一致的（图S3），表明直接氧原子转移反应的pH依赖性。（37） 然而，PBS 和 BBS 部分抑制了 NiO 上 DMPOX 的产生，但不受单个缓冲系统或无缓冲系统中 pH 值从 3.0 到 8.0 变化的影响（图 S4）。这些结果表明，在自旋捕获 EPR 分析中，NiO 诱导的 DMPOX 生成的形成范围更广，这可能归因于与 Mn x O y 诱导的 DMPOX 生成的机制差异（文本 S6）。此外，缓冲液和 MO 之间的相互作用，而不是单独的 pH 值变化，主要影响了 DMPOX 的形成。
Furthermore, the buffer conditions greatly changed both the release of Cu species and their complexation states, consequently affecting the signals observed upon dosing DMPO. (38) Notably, BBS effectively suppressed EPR signals in the CuO/DMPO system while exhibiting minimal effect on DMPO adducts in the Cu2O/DMPO system. These results indicate that the observed effects of BBS were primarily governed by pH change rather than by masking the dissolved Cu2+. In the presence of MOs, phosphate buffer largely affected the transformation of DMPO. When the pH values in different buffer systems, such as acetate and phosphate buffers, were varied, the pH change caused different influences on EPR signals (Figure S3). These results suggest the significant role of phosphate complexation in modulating the interaction between DMPO and Cu2+.
此外，缓冲条件极大地改变了Cu物质的释放及其络合状态，从而影响了DMPO加药时观察到的信号。（38）值得注意的是，BBS有效抑制了CuO/DMPO体系中的EPR信号，而对Cu 2 O/DMPO体系中的DMPO加合物的影响最小。这些结果表明，观察到的BBS效应主要受pH值变化的控制，而不是通过掩盖溶解的Cu 2+ 。在MOs存在下，磷酸盐缓冲液对DMPO的转化有很大影响。当不同缓冲液体系（如醋酸盐和磷酸盐缓冲液）的pH值发生变化时，pH值变化对EPR信号的影响不同（图S3）。这些结果表明，磷酸盐络合在调节DMPO和Cu之间的相互作用中起着重要作用 2+ 。
此外，缓冲条件极大地改变了Cu物质的释放及其络合状态，从而影响了DMPO加药时观察到的信号。（38）值得注意的是，BBS有效抑制了CuO/DMPO体系中的EPR信号，而对Cu 2 O/DMPO体系中的DMPO加合物的影响最小。这些结果表明，观察到的BBS效应主要受pH值变化的控制，而不是通过掩盖溶解的Cu 2+ 。在MOs存在下，磷酸盐缓冲液对DMPO的转化有很大影响。当不同缓冲液体系（如醋酸盐和磷酸盐缓冲液）的pH值发生变化时，pH值变化对EPR信号的影响不同（图S3）。这些结果表明，磷酸盐络合在调节DMPO和Cu之间的相互作用中起着重要作用 2+ 。
The effects of buffers on the DMPO transformation in suspensions of MnO, Fe2O3, Fe3O4, or Co3O4 were relatively insignificant. However, the presence of phosphate efficiently reduced the concentration of free Mn2+, (39) thus weakening its strong EPR signal while enhancing the DMPO–R signal. In acetate-buffered systems, a decrease in the pH level led to more dissolution of Co species, resulting in an increased DMPO–R signal. These findings reveal that buffer selection could greatly affect the results of spin-trapping experiments by affecting the DMPO transformation via altering metal ion solubility and interaction pathways. Also, pH control played a crucial role in modulating metal ion release and complexation, altering the formation of DMPO–OH and DMPO–R. To elucidate the catalytic mechanisms in buffered systems or other more complex matrices more accurately, the baseline spin-trapping signal should be taken into consideration in the EPR analysis.
缓冲液对MnO、Fe 2 O 3 、Fe 3 O 4 或Co 3 O 4 悬浮液DMPO转化的影响相对较小。然而，磷酸盐的存在有效地降低了游离Mn 2+ 的浓度（39），从而削弱了其强大的EPR信号，同时增强了DMPO-R信号。在醋酸盐缓冲系统中，pH值的降低导致Co物种的更多溶解，从而导致DMPO-R信号增加。这些发现表明，缓冲液的选择可以通过改变金属离子溶解度和相互作用途径来影响DMPO转化，从而极大地影响自旋捕获实验的结果。此外，pH控制在调节金属离子释放和络合方面起着至关重要的作用，改变了DMPO-OH和DMPO-R的形成。为了更准确地阐明缓冲系统或其他更复杂基质中的催化机制，在EPR分析中应考虑基线自旋捕获信号。
缓冲液对MnO、Fe 2 O 3 、Fe 3 O 4 或Co 3 O 4 悬浮液DMPO转化的影响相对较小。然而，磷酸盐的存在有效地降低了游离Mn 2+ 的浓度（39），从而削弱了其强大的EPR信号，同时增强了DMPO-R信号。在醋酸盐缓冲系统中，pH值的降低导致Co物种的更多溶解，从而导致DMPO-R信号增加。这些发现表明，缓冲液的选择可以通过改变金属离子溶解度和相互作用途径来影响DMPO转化，从而极大地影响自旋捕获实验的结果。此外，pH控制在调节金属离子释放和络合方面起着至关重要的作用，改变了DMPO-OH和DMPO-R的形成。为了更准确地阐明缓冲系统或其他更复杂基质中的催化机制，在EPR分析中应考虑基线自旋捕获信号。
Identification of DMPO–R DMPO-R的鉴定
In the systems containing MOs and DMPO only, the DMPO–R signal was detected. In previous studies, such DMPO–R signals were attributed to the degradation of DMPO–OH through ion-mediated pathways involving ions such as Cu2+ or Fe3+. (13) However, the results of the detailed EPR analysis indicate the potential for DMPO–R to be the exclusive spin-trapping product in certain systems without the simultaneous presence of a DMPO–OH signal (Figure S3). Thus, DMPO–R might be generated before the formation of DMPO–OH, rather than as the degradation product of DMPO–OH.
在仅包含MO和DMPO的系统中，检测到DMPO-R信号。在以前的研究中，这种 DMPO-R 信号归因于 DMPO-OH 通过涉及 Cu 2+ 或 Fe 等离子的离子介导的途径降解 3+ 。（13） 然而，详细的 EPR 分析结果表明，DMPO-R 有可能成为某些系统中的独家自旋捕获产物，而不会同时存在 DMPO-OH 信号（图 S3）。因此，DMPO-R可能在DMPO-OH形成之前产生，而不是作为DMPO-OH的降解产物。
在仅包含MO和DMPO的系统中，检测到DMPO-R信号。在以前的研究中，这种 DMPO-R 信号归因于 DMPO-OH 通过涉及 Cu 2+ 或 Fe 等离子的离子介导的途径降解 3+ 。（13） 然而，详细的 EPR 分析结果表明，DMPO-R 有可能成为某些系统中的独家自旋捕获产物，而不会同时存在 DMPO-OH 信号（图 S3）。因此，DMPO-R可能在DMPO-OH形成之前产生，而不是作为DMPO-OH的降解产物。
The EPR spectra obtained in the CuO/DMPO and Cu2O/DMPO systems were successfully simulated as a sum of DMPO–OH and DMPO–R signals (Figure 1d). The dominant component was simulated with AN = 14.78 G and AH = 14.78 G and assigned to the DMPO–OH adduct. Another component, simulated with AN = 15.48 G and AH = 22.53 G, was assigned to a DMPO adduct with a C-centric radical (Tables S2 and S3). These systems were specifically chosen for determining the chemical formula of the DMPO–R adduct. Subsequent LC-MS/MS analysis shows an ion of m/z 226.16 corresponding in mass to the DMPO dimer (C12H22N2O2•+, theoretical mass = 226.17), which was identified at a retention time of 6.48 min in both the CuO/DMPO and the Cu2O/DMPO systems. This finding suggests that the prevalent DMPO–R formation in DMPO/MO systems could be attributed to DMPO dimerization catalyzed by leached transition metal ions. Usually, such a signal could not be readily identified and poses challenges for attributed to its formation. Moreover, the formation of DMPO–R in spin-trapping systems using alcohols or DMSO as quenchers is a crucial indicator for the generation of HO• radicals. (13,40) Thus, in spin-trapping studies involving transition metal-based catalytic oxidations, such an interfered signal caused by the commonly occurring DMPO dimerization should be carefully examined.
在CuO/DMPO和Cu 2 O/DMPO系统中获得的EPR谱图被成功模拟为DMPO-OH和DMPO-R信号的总和（图1d）。用 A N = 14.78 G 和 A H = 14.78 G 模拟主要成分，并将其分配给 DMPO-OH 加合物。另一种组分，用 A N = 15.48 G 和 A H = 22.53 G 模拟，分配给具有 C 中心自由基的 DMPO 加合物（表 S2 和 S3）。这些系统是专门用于确定DMPO-R加合物的化学式而选择的。随后的LC-MS/MS分析显示，在CuO/DMPO和Cu O/DMPO系统中，该离子的质量值为m/z 226.16，其质量 12 22 2 2 •+ 值为226.17，在CuO/DMPO和Cu O/DMPO系统中均以6.48 min的保留时间鉴定。 2 这一发现表明，DMPO/MO体系中普遍存在的DMPO-R可归因于浸出过渡金属离子催化的DMPO二聚化。通常，这种信号不容易识别，并且对其形成提出了挑战。此外，在使用醇或DMSO作为淬灭剂的自旋捕获系统中DMPO-R的形成是HO • 自由基生成的关键指标。（13,40） 因此，在涉及基于过渡金属的催化氧化的自旋捕获研究中，应仔细检查由常见发生的 DMPO 二聚化引起的这种干扰信号。
在CuO/DMPO和Cu 2 O/DMPO系统中获得的EPR谱图被成功模拟为DMPO-OH和DMPO-R信号的总和（图1d）。用 A N = 14.78 G 和 A H = 14.78 G 模拟主要成分，并将其分配给 DMPO-OH 加合物。另一种组分，用 A N = 15.48 G 和 A H = 22.53 G 模拟，分配给具有 C 中心自由基的 DMPO 加合物（表 S2 和 S3）。这些系统是专门用于确定DMPO-R加合物的化学式而选择的。随后的LC-MS/MS分析显示，在CuO/DMPO和Cu O/DMPO系统中，该离子的质量值为m/z 226.16，其质量 12 22 2 2 •+ 值为226.17，在CuO/DMPO和Cu O/DMPO系统中均以6.48 min的保留时间鉴定。 2 这一发现表明，DMPO/MO体系中普遍存在的DMPO-R可归因于浸出过渡金属离子催化的DMPO二聚化。通常，这种信号不容易识别，并且对其形成提出了挑战。此外，在使用醇或DMSO作为淬灭剂的自旋捕获系统中DMPO-R的形成是HO • 自由基生成的关键指标。（13,40） 因此，在涉及基于过渡金属的催化氧化的自旋捕获研究中，应仔细检查由常见发生的 DMPO 二聚化引起的这种干扰信号。
Quenching Effects on the DMPO Transformation
对DMPO转变的淬灭效应
Quenching experiments are essential for identifying reactive species in catalytic water purification processes. (41) However, the interaction of these alcohols with reactive species exhibits complex behaviors, governed by both quenching and solvent effects. Thus, the selectivity of quenchers, such as methanol (MeOH) and ethanol (EtOH) for both HO• and SO4•–, and tert-butyl alcohol (tBuOH) and isopropanol (iPrOH) for HO•, has been questioned due to the expanding diversity of recognized reactive species. (8) We have previously demonstrated that the EPR signal could be generated via nonradical pathways on the MO surfaces, further challenging the conventional views of radical involvement based on quencher selectivity. Therefore, comprehensive quenching experiments, combined with detailed EPR analysis, are essential to enhancing our understanding of the reactive species and their roles in complex oxidation processes.
淬灭实验对于识别催化水净化过程中的反应性物质至关重要。（41） 然而，这些醇与反应性物质的相互作用表现出复杂的行为，受淬灭和溶剂效应的控制。因此，由于公认的反应性物种的多样性不断扩大 • ，淬灭剂的选择性受到质疑，例如甲醇（MeOH）和乙醇（EtOH）对HO • 和SO 4 •– 的选择性，以及叔丁醇（tBuOH）和异丙醇（iPrOH）对HO的选择性。（8） 我们之前已经证明 EPR 信号可以通过 MO 表面上的非自由基途径产生，进一步挑战了基于淬灭剂选择性的自由基参与的传统观点。因此，全面的淬灭实验，结合详细的EPR分析，对于增强我们对活性物质及其在复杂氧化过程中的作用的理解至关重要。
淬灭实验对于识别催化水净化过程中的反应性物质至关重要。（41） 然而，这些醇与反应性物质的相互作用表现出复杂的行为，受淬灭和溶剂效应的控制。因此，由于公认的反应性物种的多样性不断扩大 • ，淬灭剂的选择性受到质疑，例如甲醇（MeOH）和乙醇（EtOH）对HO • 和SO 4 •– 的选择性，以及叔丁醇（tBuOH）和异丙醇（iPrOH）对HO的选择性。（8） 我们之前已经证明 EPR 信号可以通过 MO 表面上的非自由基途径产生，进一步挑战了基于淬灭剂选择性的自由基参与的传统观点。因此，全面的淬灭实验，结合详细的EPR分析，对于增强我们对活性物质及其在复杂氧化过程中的作用的理解至关重要。
MeOH exhibited distinguishable quenching effects on DMPOX generation on the MO surfaces, particularly in the DMPO/NiO system, where it entirely suppressed the strong DMPOX signal (Figure 2a). This result indicates that MeOH, different from other alcohols, exhibited a unique effectiveness in interrupting direct oxygen transfer on MO surfaces. After recognizing the possible misleading results, a comparative analysis of its quenching performance with other quenchers could provide new insights into the role of direct oxygen transfer in catalytic oxidations. Conversely, other alcohols had a negligible influence on DMPOX generation but caused DMPOX generation in the DMPO/Co3O4 system, implying a solvent-dependent oxygen transfer mechanism. Besides, these alcohols did not affect the generated DMPO adducts, including DMPO–OH and DMPO–R. Consequently, the nonquenchable signal observed in EPR analysis might be attributable to the DMPO transformation catalyzed by metal ions rather than the generation of HO• or R•. The comparison between different alcohols indicates that the complex interactions between alcohols and reactive species affect radical identification and mechanistic understanding in catalytic processes.
MeOH 对 MO 表面的 DMPOX 生成表现出明显的猝灭作用，特别是在 DMPO/NiO 系统中，它完全抑制了强烈的 DMPOX 信号（图 2a）。该结果表明，与其他醇不同，MeOH在阻断MO表面的直接氧转移方面表现出独特的有效性。在认识到可能的误导性结果后，对其与其他淬火剂的淬火性能进行比较分析可以为直接氧转移在催化氧化中的作用提供新的见解。相反，其他醇类对DMPOX生成的影响可以忽略不计，但在DMPO/Co 3 O 4 系统中引起DMPOX的产生，这意味着溶剂依赖性氧转移机制。此外，这些醇类不会影响生成的DMPO加合物，包括DMPO-OH和DMPO-R。因此，在EPR分析中观察到的不可熄灭信号可能归因于金属离子催化的DMPO转化，而不是HO • 或R的产生 • 。不同醇类之间的比较表明，醇类和反应性物质之间的复杂相互作用会影响催化过程中的自由基鉴定和机理理解。
MeOH 对 MO 表面的 DMPOX 生成表现出明显的猝灭作用，特别是在 DMPO/NiO 系统中，它完全抑制了强烈的 DMPOX 信号（图 2a）。该结果表明，与其他醇不同，MeOH在阻断MO表面的直接氧转移方面表现出独特的有效性。在认识到可能的误导性结果后，对其与其他淬火剂的淬火性能进行比较分析可以为直接氧转移在催化氧化中的作用提供新的见解。相反，其他醇类对DMPOX生成的影响可以忽略不计，但在DMPO/Co 3 O 4 系统中引起DMPOX的产生，这意味着溶剂依赖性氧转移机制。此外，这些醇类不会影响生成的DMPO加合物，包括DMPO-OH和DMPO-R。因此，在EPR分析中观察到的不可熄灭信号可能归因于金属离子催化的DMPO转化，而不是HO • 或R的产生 • 。不同醇类之间的比较表明，醇类和反应性物质之间的复杂相互作用会影响催化过程中的自由基鉴定和机理理解。
Figure 2 图2
Figure 2. Quenching effects of different (a) alcohols and (b) organics on the DMPO-trapping products in the presence of transition metal oxides. Conditions: pH 3.0, [DMPO] = 100 mM, [metal oxides] = 1 g·L–1, φ(alcohols) = 1%, [organics] = 1 g·L–1. “Blank” denotes samples solely containing MO and DMPO.
图2.在过渡金属氧化物存在下，不同（a）醇和（b）有机物对DMPO捕获产物的淬灭作用。条件：pH 3.0，[DMPO]=100 mM，[金属氧化物]=1 g·L，φ –1 （醇类）=1%，[有机物]=1 g·L –1 .“空白”表示仅含有 MO 和 DMPO 的样品。
In addition, the quenching effects of common aromatic organics were explored, revealing their preference on involving in these nonradical transformation pathways. The oxygen transfer process exhibited high selectivity in oxidizing phenol (PhOH) and aniline (PhNH2), thus inhibiting the transformation of DMPO into DMPOX (Figure 2b). Such a process has recently been identified as a precursor stage of surface polymerization, implying that nonradical catalysis could be tracked through spin-trapping EPR analysis. (42) Establishing a catalytic cycle with an external oxidant would enable the efficient removal of organic pollutants through surface polymerization, without generating harmful byproducts.
此外，还探讨了常见芳香族有机物的猝灭作用，揭示了它们参与这些非自由基转化途径的偏好。氧转移过程在氧化苯酚（PhOH）和苯胺（PhNH）中表现出高选择性 2 ，从而抑制DMPO转化为DMPO（图2b）。这种过程最近被确定为表面聚合的前体阶段，这意味着可以通过自旋捕获EPR分析来跟踪非自由基催化。（42） 用外部氧化剂建立催化循环将能够通过表面聚合有效地去除有机污染物，而不会产生有害的副产物。
此外，还探讨了常见芳香族有机物的猝灭作用，揭示了它们参与这些非自由基转化途径的偏好。氧转移过程在氧化苯酚（PhOH）和苯胺（PhNH）中表现出高选择性 2 ，从而抑制DMPO转化为DMPO（图2b）。这种过程最近被确定为表面聚合的前体阶段，这意味着可以通过自旋捕获EPR分析来跟踪非自由基催化。（42） 用外部氧化剂建立催化循环将能够通过表面聚合有效地去除有机污染物，而不会产生有害的副产物。
Interestingly, although Ni in NiO was at low valence with limited oxidability, it exhibited a high efficiency in obtaining electrons from DMPO, PhOH, and PhNH2. Moreover, it could react with p-benzoquinone (pBQ), and the subsequent semiquinone radical was also trapped by DMPO (Figure 2b). These features suggest a potential role of NiO in the selective transformation of organic pollutants, paving the way for future applications in water purification. Selecting PMS as the external oxidant, we have successfully achieved a highly efficient polymerization degradation of PhOH at a ratio (direct oxidative transfer process ratio) of 92.9% (Figure S10 and Text S8). (42) Therefore, the signals detected in spin-trapping EPR analysis without oxidant dosing should not be prematurely disregarded as false positives but rather considered as an insight into nonradical pathway mechanisms. The ion-mediated pathways have not shown remarkable reflection on the organic dosing, in accordance with the fact that these ions cannot directly remove organic pollutants. Such misleading signals can be effectively differentiated through kinetic EPR analysis. (10)
有趣的是，尽管NiO中的Ni价较低，氧化性有限，但它在从DMPO、PhOH和PhNH中获取电子方面表现出很高的效率 2 。此外，它可能与对苯醌（pBQ）反应，随后的半醌自由基也被DMPO捕获（图2b）。这些特征表明NiO在有机污染物的选择性转化中具有潜在作用，为未来在水净化中的应用铺平了道路。选择PMS作为外部氧化剂，我们成功地实现了PhOH的高效聚合降解，比例（直接氧化转移过程比）为92.9%（图S10和文本S8）。（42） 因此，在未添加氧化剂的自旋捕获 EPR 分析中检测到的信号不应过早地被视为假阳性，而应被视为对非自由基途径机制的洞察。离子介导的途径对有机物投加没有表现出显著的反射，因为这些离子不能直接去除有机污染物。这种误导性信号可以通过动力学EPR分析得到有效区分。(10)
有趣的是，尽管NiO中的Ni价较低，氧化性有限，但它在从DMPO、PhOH和PhNH中获取电子方面表现出很高的效率 2 。此外，它可能与对苯醌（pBQ）反应，随后的半醌自由基也被DMPO捕获（图2b）。这些特征表明NiO在有机污染物的选择性转化中具有潜在作用，为未来在水净化中的应用铺平了道路。选择PMS作为外部氧化剂，我们成功地实现了PhOH的高效聚合降解，比例（直接氧化转移过程比）为92.9%（图S10和文本S8）。（42） 因此，在未添加氧化剂的自旋捕获 EPR 分析中检测到的信号不应过早地被视为假阳性，而应被视为对非自由基途径机制的洞察。离子介导的途径对有机物投加没有表现出显著的反射，因为这些离子不能直接去除有机污染物。这种误导性信号可以通过动力学EPR分析得到有效区分。(10)
Implications 影响
In this work, we conducted a thorough examination to understand the interactions between radical trap DMPO and various MOs. We identified two oxidant-independent pathways for DMPO transformation: (i) a direct oxygen transfer mechanism transforming DMPO into DMPOX and (ii) a process mediated by dissolved transition metal ions, resulting in the conversion of DMPO to either DMPO–OH or DMPO–R. These DMPO transformations, which have been insufficiently recognized, have led to numerous misleading results in the radical identification in catalytic water purification processes. Furthermore, transition metal-based catalysts have found widespread applications, implying that the spin-trapping EPR signals induced by dissolved metal ions might mislead the radical identifications in various fields. As a result, the conventional spin-trapping EPR analysis for definitive evidence of radical presence must be re-evaluated. Instead, we advocate for a more comprehensive approach via combining kinetic EPR analysis (Figure S11 and Text S9) with systematic quenching strategies, for a deeper mechanistic insight. Furthermore, the direct interactions between DMPO and MOs shed new light on the processes of surface accumulation and polymerization of organic pollutants, thereby enriching our understanding of EPR analyses in nonradical oxidations. Since the crucial role surface catalysis plays in engineered systems and natural environments, the catalytic mechanisms of oxidations in complex matrices should be thoroughly investigated.
在这项工作中，我们进行了彻底的检查，以了解自由基陷阱DMPO与各种MO之间的相互作用。我们确定了两种与氧化剂无关的DMPO转化途径：（i）将DMPO转化为DMPOX的直接氧转移机制，以及（ii）由溶解的过渡金属离子介导的过程，导致DMPO转化为DMPO-OH或DMPO-R。这些DMPO转化没有得到充分的认可，导致了催化水净化过程中自由基鉴定中的许多误导性结果。此外，过渡金属基催化剂得到了广泛的应用，这意味着溶解金属离子诱导的自旋捕获EPR信号可能会误导各个领域的自由基鉴定。因此，必须重新评估传统的自旋捕获 EPR 分析，以寻找自由基存在的明确证据。相反，我们提倡通过将动力学EPR分析（图S11和文本S9）与系统淬灭策略相结合来采用更全面的方法，以获得更深入的机理见解。此外，DMPO和MOs之间的直接相互作用为有机污染物的表面积累和聚合过程提供了新的视角，从而丰富了我们对非自由基氧化中EPR分析的理解。由于表面催化在工程系统和自然环境中起着至关重要的作用，因此应深入研究复杂基质中氧化的催化机理。
在这项工作中，我们进行了彻底的检查，以了解自由基陷阱DMPO与各种MO之间的相互作用。我们确定了两种与氧化剂无关的DMPO转化途径：（i）将DMPO转化为DMPOX的直接氧转移机制，以及（ii）由溶解的过渡金属离子介导的过程，导致DMPO转化为DMPO-OH或DMPO-R。这些DMPO转化没有得到充分的认可，导致了催化水净化过程中自由基鉴定中的许多误导性结果。此外，过渡金属基催化剂得到了广泛的应用，这意味着溶解金属离子诱导的自旋捕获EPR信号可能会误导各个领域的自由基鉴定。因此，必须重新评估传统的自旋捕获 EPR 分析，以寻找自由基存在的明确证据。相反，我们提倡通过将动力学EPR分析（图S11和文本S9）与系统淬灭策略相结合来采用更全面的方法，以获得更深入的机理见解。此外，DMPO和MOs之间的直接相互作用为有机污染物的表面积累和聚合过程提供了新的视角，从而丰富了我们对非自由基氧化中EPR分析的理解。由于表面催化在工程系统和自然环境中起着至关重要的作用，因此应深入研究复杂基质中氧化的催化机理。
Supporting Information 支持信息
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.estlett.4c00155.
支持信息可在 https://pubs.acs.org/doi/10.1021/acs.estlett.4c00155
免费获得。
More details regarding the methodology including LC-MS/MS analysis and EPR spectra simulation, pH value of oxidant solutions, simulation parameter, total ion current in LC-MS analysis, and effect of pH on DMPO-trapping signals (PDF)
有关该方法的更多详细信息，包括 LC-MS/MS 分析和 EPR 谱图模拟、氧化剂溶液的 pH 值、模拟参数、LC-MS 分析中的总离子电流以及 pH 值对 DMPO 捕获信号的影响 （ PDF）
Terms & Conditions 条款及细则
Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.
大多数电子支持信息文件无需订阅 ACS Web Editions 即可获得。此类文件可以按文章下载用于研究用途（如果有与相关文章相关的公共使用许可证，则该许可证可能允许其他用途）。可以通过 RightsLink 权限系统请求从 ACS 获得用于其他用途的许可：http://pubs.acs.org/page/copyright/permissions.html。
Author Information 作者信息
- Han-Qing Yu - CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China;
https://orcid.org/0000-0001-5247-6244;
俞汉青 - 中国科学技术大学环境科学与工程系，中国科学院城市污染物转化重点实验室，合肥230026; https://orcid.org/0000-0001-5247-6244;电子邮件： hqyu@ustc.edu.cn
- Jing-Hang Wu - CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China;https://orcid.org/0000-0002-8087-8440
吴静航 - 中国科学技术大学环境科学与工程系，中国科学院城市污染物转化重点实验室，安徽 230026; https://orcid.org/0000-0002-8087-8440
Acknowledgments 确认
The authors thank the National Natural Science Foundation of China (52192684, 51821006, and 52027815), for supporting this work. The authors also thank Ms. Haiyan Zhang at USTC for helping with the LC-MS analysis. Jing-Hang Wu acknowledges the financial support from Shanghai Tongji Gao Tingyao Environmental Science & Technology Development Foundation (STGEF), China.
作者感谢中国国家自然科学基金（52192684、51821006和52027815）对这项工作的支持。作者还感谢中国科学技术大学的张海燕女士对LC-MS分析的帮助。吴静航感谢中国上海同济高廷遥环境科技发展基金会（STGEF）的资助。
References 引用
This article references 42 other publications.
本文引用了其他 42 篇出版物。
- 1He, F.; Zhao, W.; Liang, L.; Gu, B. Photochemical oxidation of dissolved elemental mercury by carbonate radicals in water. Environ. Sci. Technol. Lett.IF 10.9SCIEJCI 1.42Q1环境科学与生态学2区2014, 1, 499– 503, DOI: 10.1021/ez500322f Google Scholar Google 学术搜索1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvV2nt7nM&md5=dccb031b7d30f672468b4945d6a252d4Photochemical Oxidation of Dissolved Elemental Mercury by Carbonate Radicals in WaterHe, Feng; Zhao, Weirong; Liang, Liyuan; Gu, BaohuaEnvironmental Science & Technology Letters (2014), 1 (12), 499-503CODEN: ESTLCU; ISSN:2328-8930. (American Chemical Society)Photochem. oxidn. of dissolved elemental mercury, Hg(0), affects mercury chem. speciation and its transfer at the water-air interface in the aquatic environment. The mechanisms and factors that control Hg(0) photooxidn., however, are not completely understood, esp. concerning the role of dissolved org. matter (DOM) and carbonate (CO32-) in natural freshwaters. Here, we evaluate Hg(0) photooxidn. rates affected by reactive ionic species (e.g., DOM, CO32-, and NO3-) and free radicals in creek water and a phosphate buffer soln. (pH 8) under simulated solar irradn. The Hg(0) photooxidn. rate (k = 1.44/h) is much higher in the presence of both CO32- and NO3- than in the presence of CO32-, NO3-, or DOM alone (k = 0.1-0.17/h). Using scavengers and enhancers for singlet oxygen (1O2) and hydroxyl (HO•) radicals, as well as ESR spectroscopy, we found that carbonate radicals (CO3•-) primarily drive Hg(0) photooxidn. The addn. of DOM to the soln. of CO32- and NO3- decreased the oxidn. rate by half. This study identifies an unrecognized pathway of Hg(0) photooxidn. by CO3•- radicals and the inhibitory effect of DOM, which could be important in assessing Hg transformation and the fate of Hg in water contg. carbonate such as hard water and seawater.
1他，F.;赵，W.;梁，L.;Gu， B.水中碳酸盐自由基对溶解元素汞的光化学氧化.环境。Sci. Technol. Lett.2014， 1， 499– 503， DOI： 10.1021/ez500322f - 2Pan, Y.; Zheng, X.; Zhao, G.; Rao, Z.; Yu, W.; Chen, B.; Chu, C. Water vapor condensation on iron minerals spontaneously produces hydroxyl radical. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2023, 57, 8610– 8616, DOI: 10.1021/acs.est.3c01379 Google Scholar Google 学术搜索2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhtVOns7zM&md5=1a444dd07fa23085e84328f8d3cee498Water Vapor Condensation on Iron Minerals Spontaneously Produces Hydroxyl RadicalPan, Yishuai; Zheng, Xiaoshan; Zhao, Guoqiang; Rao, Zepeng; Yu, Wanchao; Chen, Baoliang; Chu, ChihengEnvironmental Science & Technology (2023), 57 (23), 8610-8616CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)The hydroxyl radical (•OH) is a potent oxidant and key reactive species in mediating element cycles and pollutant dynamics in the natural environment. The natural source of •OH is historically linked to photochem. processes (e.g., photoactivation of natural org. matter or iron minerals) or redox chem. processes (e.g., reaction of microbe-excreted or reduced iron/natural org. matter/sulfide-released electrons with O2 in soils and sediments). This study revealed a ubiquitous source of •OH prodn. via water vapor condensation on iron mineral surfaces. Distinct •OH productions (15-478 nM via water vapor condensation) were obsd. on all investigated iron minerals of abundant natural occurrence (i.e., goethite, hematite, and magnetite). The spontaneous •OH productions were triggered by contact electrification and Fenton-like activation of hydrogen peroxide (H2O2) at the water-iron mineral interface. Those •OH drove efficient transformation of org. pollutants assocd. on iron mineral surfaces. After 240 cycles of water vapor condensation and evapn., bisphenol A and carbamazepine degraded by 25%-100% and 16%-51%, resp., forming •OH-mediated arene/alkene hydroxylation products. Our findings largely broaden the natural source of •OH. Given the ubiquitous existence of iron minerals on Earth's surface, those newly discovered •OH could play a role in the transformation of pollutants and org. carbon assocd. with iron mineral surfaces.
2潘，Y.;郑旭;赵国;饶，Z.;俞，W.;陈，B.;Chu， C.水蒸气在铁矿物上凝结自发产生羟基自由基。环境。Sci. Technol.2023， 57， 8610– 8616， DOI： 10.1021/acs.est.3c01379 - 3Sun, M.; Chu, C.; Geng, F.; Lu, X.; Qu, J.; Crittenden, J.; Elimelech, M.; Kim, J.-H. Reinventing Fenton chemistry: Iron oxychloride nanosheet for pH-insensitive H2O2 activation. Environ. Sci. Technol. Lett.IF 10.9SCIEJCI 1.42Q1环境科学与生态学2区2018, 5, 186– 191, DOI: 10.1021/acs.estlett.8b00065 Google Scholar Google 学术搜索3https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXivFWgsL0%253D&md5=abedcc32bd1dba36561ac8ec932d827aReinventing Fenton chemistry: iron oxychloride nanosheet for pH-insensitive H2O2 activationSun, Meng; Chu, Chiheng; Geng, Fanglan; Lu, Xinglin; Qu, Jiuhui; Crittenden, John; Elimelech, Menachem; Kim, Jae-HongEnvironmental Science & Technology Letters (2018), 5 (3), 186-191CODEN: ESTLCU; ISSN:2328-8930. (American Chemical Society)This study intends to reinvent classical Fenton chem. by enabling the Fe(II)/Fe(III) redox cycle to occur on a newly developed FeOCl nanosheet catalyst for facile hydroxyl radical (•OH) generation from H2O2 activation. This approach overcomes challenges such as low operating pH and large sludge prodn. that have prevented a wider use of otherwise attractive Fenton chem. for practical water treatment, in particular, for the destruction of recalcitrant pollutants through nonselective oxidn. by •OH. We demonstrate that FeOCl catalysts exhibit the highest performance reported in the literature for •OH prodn. and org. pollutant destruction over a wide pH range. We further elucidate the mechanism of rapid conversion between Fe(III) and Fe(II) in FeOCl crystals based on extensive characterizations. Given the low-cost raw material and simple synthesis and regeneration, FeOCl catalysts represent a crit. advance toward application of iron-based advanced oxidn. in real practice.
3孙，M.;朱，C.;耿，F.;卢，X.;曲军;克里滕登，J.;以利米勒，M.;Kim， J.-H.Reinventing Fenton chemistry： Iron oxychloride nanosheet for pH insensitive H 2 O 2 activation.环境。Sci. Technol. Lett.2018， 5， 186– 191， DOI： 10.1021/acs.estlett.8b00065 - 4Domingues, E.; Silva, M. J.; Vaz, T.; Gomes, J.; Martins, R. C. Sulfate radical based advanced oxidation processes for agro-industrial effluents treatment: A comparative review with Fenton’s peroxidation. Sci. Total Environ.IF 9.8SCIEJCI 1.68Q1环境科学与生态学1区Top2022, 832, 155029, DOI: 10.1016/j.scitotenv.2022.155029 Google Scholar Google 学术搜索4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhtValtL%252FO&md5=ef5486ee2a70b09f8149713e83d8a25aSulfate radical based advanced oxidation processes for agro-industrial effluents treatment: A comparative review with Fenton's peroxidationDomingues, Eva; Silva, Maria Joao; Vaz, Telma; Gomes, Joao; Martins, Rui C.Science of the Total Environment (2022), 832 (), 155029CODEN: STENDL; ISSN:0048-9697. (Elsevier B.V.)A review. Agro-industrial wastewater management becomes a major task while environmental regulations are becoming stricter worldwide. Agro-industrial wastewaters are known by high content of org. pollutants that cause an adverse effect on the water bodies. Industries are looking for efficient, easy-to-use and affordable treatment processes. Sulfate radical based advanced oxidn. processes (S-AOPs) are arising as suitable alternatives for agro-industrial effluents treatment. In this review, the major findings regarding the application of this technol. for real agro-industrial wastewater depuration are discussed. Moreover, these technologies are compared as an alternative to Fenton's process, which is a widely studied advanced oxidn. process and with high efficiency in the treatment of agro-industrial effluents. The studies already carried out are promising, but there is still a great lack of studies in this area and using this technique.
4多明格斯，E.;席尔瓦，MJ;瓦兹，T.;戈麦斯，J.;Martins， R. C.基于硫酸盐自由基的先进氧化工艺用于农用工业废水处理：与芬顿过氧化的比较综述。Sci. Total Environ.2022， 832， 155029， DOI： 10.1016/j.scitotenv.2022.155029 - 5Gligorovski, S.; Strekowski, R.; Barbati, S.; Vione, D. Environmental implications of hydroxyl radicals (•OH). Chem. Rev.IF 62.1SCIEJCI 4.2Q1化学1区Top2015, 115, 13051– 13092, DOI: 10.1021/cr500310b Google Scholar Google 学术搜索5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvFGns77L&md5=66e41bdcfb5985598a10e94578f26982Environmental Implications of Hydroxyl Radicals (•OH)Gligorovski, Sasho; Strekowski, Rafal; Barbati, Stephane; Vione, DavideChemical Reviews (Washington, DC, United States) (2015), 115 (24), 13051-13092CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)A review concerning the formation, occurrence, reactivity, scavenging, and detection of OH- in natural environmental compartments (natural water and indoor and outdoor atm.) and lab. systems is given. A comprehensive understanding of OH- sources and sinks and their implications in natural water and in the atm. is critically important, including the way surface water irradiated chromophoric dissolved org. matter yields OH- via the H2O2-independent pathway, and including an assessment of the relative importance of gas- vs aq.-phase OH- reactions with many atm. components. Topics discussed include: introduction; OH- formation and scavenging under different conditions (aq. environment, atm., indoor atm.); OH- generation under controlled lab. conditions (aq. phase, gas phase); OH- prodn. and prodn.-detection in the lab. and gaseous and aq. phases; OH- kinetic properties in aq. soln.; OH- reaction mechanisms in aq. soln. and in gas phase; and conclusions and outlook.
5格利戈罗夫斯基，S.;斯特雷科夫斯基，R.;巴尔巴蒂，S.;Vione， D.羟基自由基（ • OH）的环境影响。Chem. Rev.2015， 115， 13051– 13092， DOI： 10.1021/cr500310b - 6Lee, J.; von Gunten, U.; Kim, J.-H. Persulfate-based advanced oxidation: Critical assessment of opportunities and roadblocks. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2020, 54, 3064– 3081, DOI: 10.1021/acs.est.9b07082 Google Scholar Google 学术搜索6https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXjtFygt7c%253D&md5=34d866a241ac273c7c2b57add9c89ef7Persulfate-Based Advanced Oxidation: Critical Assessment of Opportunities and RoadblocksLee, Jaesang; von Gunten, Urs; Kim, Jae-HongEnvironmental Science & Technology (2020), 54 (6), 3064-3081CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)A review. Reports that promote persulfate-based advanced oxidn. process (AOP) as a viable alternative to H2O2-based processes have been rapidly accumulating in recent H2O treatment literature. Various strategies to activate peroxide bonds in persulfate precursors have been proposed and the capacity to degrade a wide range of org. pollutants has been demonstrated. Compared to traditional AOPs in which hydroxyl radical serves as the main oxidant, persulfate-based AOPs have been claimed to involve different in situ generated oxidants such as sulfate radical and singlet O as well as non-radical oxidn. pathways. However, there exist controversial observations and interpretations around some of these claims, challenging robust scientific progress of this technol. toward practical use. This Crit. Review comparatively examines the activation mechanisms of peroxymonosulfate and peroxydisulfate and the formation pathways of oxidizing species. Properties of the main oxidizing species are scrutinized and the role of singlet O is debated. The impacts of H2O parameters and constituents such as pH, background org. matter, halide, phosphate, and carbonate on persulfate-driven chem. are discussed. The opportunity for niche applications is also presented, emphasizing the need for parallel efforts to remove currently prevalent knowledge roadblocks.
6李，J.;von Gunten，美国;Kim， J.-H.基于过硫酸盐的先进氧化：对机会和障碍的批判性评估。环境。Sci. Technol.2020， 54， 3064– 3081， DOI： 10.1021/acs.est.9b07082 - 7Chae, S. H.; Kim, M. S.; Kim, J.-H.; Fortner, J. D. Nanobubble reactivity: Evaluating hydroxyl radical generation (or lack thereof) under ambient conditions. ACS EST Engg. 2023, 3, 1504, DOI: 10.1021/acsestengg.3c00124 Google Scholar Google 学术搜索There is no corresponding record for this reference.
7蔡，S.H.;金，M.S.;金，J.-H.;Fortner， J. D.纳米气泡反应性：评估环境条件下羟基自由基的产生（或缺乏羟基自由基）。ACS EST Engg.2023， 3， 1504， DOI： 10.1021/acsestengg.3c00124 - 8Liu, W.; Lu, Y.; Dong, Y.; Jin, Q.; Lin, H. A critical review on reliability of quenching experiment in advanced oxidation processes. Chem. Eng. J.IF 15.1SCIEJCI 1.99Q1工程技术1区Top2023, 466, 143161, DOI: 10.1016/j.cej.2023.143161 Google Scholar Google 学术搜索8https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXovVKjs7w%253D&md5=1729690a71998985a9974bc299a15f63A critical review on reliability of quenching experiment in advanced oxidation processesLiu, Wei; Lu, Yanrong; Dong, Yingbo; Jin, Qi; Lin, HaiChemical Engineering Journal (Amsterdam, Netherlands) (2023), 466 (), 143161CODEN: CMEJAJ; ISSN:1385-8947. (Elsevier B.V.)Advanced oxidn. processes (AOPs) are promising, efficient and eco-friendly technologies for treatment of various org. wastewater. However, it has found that the identification of reactive species (RS) (e.g., •OH, SO-•4, 1O2, O-•2, h+, Cl•) during investigating catalytic and degrdn. mechanism is confused, maybe misunderstand the truth of RS contribution for degrdn. Therefore, do we really understand the RS prodn., transformation process and the corresponding influencing factors. This is the key to correctly perform quenching expt. of RS and reveal precise catalytic degrdn. mechanism. This review comprehensively presents on the state-of-the-art research progress of the formation of RS in various AOPs, quenching expt., reaction kinetics of RS and typical influencing factors on RS formation. Further, the main problems in the whole process of RS formation, transformation, identification, and related methods are discussed in detail. Finally, based on overall understanding, challenges for deeply revealing catalytic degrdn. mechanism via correctly obtaining the quenching results of RS are proposed. This review may help researchers to deeply understand the quenching process of RS in AOPs and make clear the real catalytic degrdn. mechanism of different org. pollutants.
8刘文;卢，Y.;董Y.;金Q.;Lin， H.A critical review on reliability of quenching experiment in advanced oxidation processes.化学工程 J.2023， 466， 143161， DOI： 10.1016/j.cej.2023.143161 - 9Jing, Y.; Chaplin, B. P. Mechanistic study of the validity of using hydroxyl radical probes to characterize electrochemical advanced oxidation processes. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2017, 51, 2355– 2365, DOI: 10.1021/acs.est.6b05513 Google Scholar Google 学术搜索9https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXnslWgtA%253D%253D&md5=c7923be0eac7cc9573c9dd985d3333a0Mechanistic Study of the Validity of Using Hydroxyl Radical Probes To Characterize Electrochemical Advanced Oxidation ProcessesJing, Yin; Chaplin, Brian P.Environmental Science & Technology (2017), 51 (4), 2355-2365CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)The detection of hydroxyl radicals (OH•) is typically accomplished by using reactive probe mols., but prior studies have not thoroughly studied the suitability of these probes for use in electrochem. advanced oxidn. processes (EAOPs), due to the neglect of alternative reaction mechanisms. The authors studied the suitability of four OH• probes (coumarin, p-chlorobenzoic acid, terephthalic acid, and p-benzoquinone) for use in EAOPs. Both coumarin and p-chlorobenzoic acid are oxidized via direct electron transfer reactions, while p-benzoquinone and terephthalic acid are not. Coumarin oxidn. to form the OH• adduct product 7-hydroxycoumarin was found at anodic potentials lower than that necessary for OH• formation. D. functional theory (DFT) simulations found a thermodynamically favorable and non-OH• mediated pathway for 7-hydroxycoumarin formation, which is activationless at anodic potentials > 2.10 V/SHE. DFT simulations also provided ests. of E° values for OH• probe compds., which agreed with voltammetry results. Results from this study indicated that terephthalic acid is the most appropriate OH• probe compd. for the characterization of electrochem. and catalytic systems.
9静，Y.;卓别林，B.P.使用羟基自由基探针表征电化学高级氧化过程的有效性的机理研究。环境。Sci. Technol.2017， 51， 2355– 2365， DOI： 10.1021/acs.est.6b05513 - 10Wu, J.-H.; Chen, F.; Yang, T.-H.; Yu, H.-Q. Unveiling singlet oxygen spin trapping in catalytic oxidation processes using in situ kinetic EPR analysis. Proc. Natl. Acad. Sci. U.S.A.IF 11.1SCIEJCI 2.52Q1综合性期刊1区Top2023, 120, e2305706120, DOI: 10.1073/pnas.2305706120 Google Scholar Google 学术搜索There is no corresponding record for this reference.
10吴俊华;陈，F.;杨太华;Yu， H.-Q.使用原位动力学EPR分析揭示催化氧化过程中的单线态氧自旋捕获。美国国家科学院院刊 2023， 120， e2305706120， DOI： 10.1073/pnas.2305706120 - 11Saito, K.; Sail, D.; Yamamoto, K.; Matsumoto, S.; Blackman, B.; Kishimoto, S.; Brender, J. R.; Swenson, R. E.; Mitchell, J. B.; Krishna, M. C. Synthesis and evaluation of 13C-labeled 5–5-dimethyl-1-pyrroline-N-oxide aimed at in vivo detection of reactive oxygen species using hyperpolarized 13C-MRI. Free Radic. Biol. Med.IF 7.4SCIEJCI 1.47Q1生物学2区Top2019, 131, 18– 26, DOI: 10.1016/j.freeradbiomed.2018.11.013 Google Scholar Google 学术搜索11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXitl2it7zM&md5=0e4fc64944e15ad6feff9a0047f6db01Synthesis and evaluation of 13C-labeled 5-5-dimethyl-1-pyrroline-N-oxide aimed at in vivo detection of reactive oxygen species using hyperpolarized 13C-MRISaito, Keita; Sail, Deepak; Yamamoto, Kazutoshi; Matsumoto, Shingo; Blackman, Burchelle; Kishimoto, Shun; Brender, Jeffrey R.; Swenson, Rolf E.; Mitchell, James B.; Krishna, Murali C.Free Radical Biology & Medicine (2019), 131 (), 18-26CODEN: FRBMEH; ISSN:0891-5849. (Elsevier B.V.)Effective means to identify the role of reactive oxygen species (ROS) mediating several diseases including cancer, ischemic heart disease, stroke, Alzheimer's and other inflammatory conditions in in vivo models would be useful. The cyclic nitrone 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) is a spin trap frequently used to detect free radicals in vitro using EPR spectroscopy. The authors synthesized 13C-labeled DMPO for hyperpolarization by dynamic nuclear polarization, in which 13C NMR signal increases >10,000-fold. This allows in vivo 13C MRI to study the feasibility of in vivo ROS detection by the 13C-MRI. DMPO was 13C-labeled at C5 position, and deuterated to prolong the T1 relaxation time. The overall yield achieved for 5-13C-DMPO-d9 was 15%. Hyperpolarized 5-13C-DMPO-d9 provided a single peak at 76 ppm in the 13C-spectrum, and the T1 was 60 s in phosphate buffer making it optimal for in vivo 13C MRI. The buffered soln. of hyperpolarized 5-13C-DMPO-d9 was injected into a mouse placed in a 3 T scanner, and 13C-spectra were acquired every 1 s. In vivo studies showed the signal of 5-13C-DMPO-d9 was detected in the mouse, and the T1 decay of 13C signal of hyperpolarized 5-13C-DMPO-d9 was 29 s 13C-chem. shift imaging revealed that 5-13C-DMPO-d9 was distributed throughout the body in a minute after the i.v. injection. A strong signal of 5-13C-DMPO-d9 was detected in heart/lung and kidney, whereas the signal in liver was small compared to other organs. The results indicate hyperpolarized 5-13C-DMPO-d9 provided sufficient 13C signal to be detected in the mouse in several organs, and can be used to detect ROS in vivo.
11斋藤，K.;赛尔，D.;山本，K.;松本，S.;布莱克曼，B.;岸本，S.;布伦德，J.R.;斯文森，RE;米切尔，JB;Krishna， M. C.C-C-标记的 13 5-5-二甲基-1-吡咯啉-N-氧化物的合成和评估，旨在使用超极化 13 C-MRI进行活性氧的体内检测。免费 Radic。Biol. Med.2019， 131， 18– 26， DOI： 10.1016/j.freeradbiomed.2018.11.013 - 12Pei, S.; You, S.; Ma, J.; Chen, X.; Ren, N. Electron spin resonance evidence for electro-generated hydroxyl radicals. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2020, 54, 13333– 13343, DOI: 10.1021/acs.est.0c05287 Google Scholar Google 学术搜索12https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhvVert7fK&md5=0d7c82290550ecafb8f44ff43ab4adccElectron Spin Resonance Evidence for Electro-generated Hydroxyl RadicalsPei, Shuzhao; You, Shijie; Ma, Jun; Chen, Xiaodong; Ren, NanqiEnvironmental Science & Technology (2020), 54 (20), 13333-13343CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Electro-generated hydroxyl radicals (•OH) are of fundamental importance to the electrochem. advanced oxidn. process (EAOP). Radical-specific ESR evidence is still lacking in assocn. with the direct electron transfer (DET) reaction of spin trap (e.g., 5,5-dimethyl-1-pyrroline-N-oxide; DMPO) and side reactions of the DMPO-OH adduct in the strongly oxidative environment offered by anodic polarization. Herein, we showed ESR identification of electro-generated •OH in EAOP based on the principle of kinetic selection. Excessive addn. of a DMPO agent and fast spin trapping allowed suitable kinetic conditions to be set for effective spin trapping of electro-generated •OH and subsequent ESR identification. Otherwise, interferential triplet signals would emerge due to formation of paramagnetic dimer via dehydrogenation, DET oxidn., and dimerization reactions of the DMPO-OH adduct. The results demonstrate that •OH formation during spin-trapping on the titanium suboxide (TiSO) anode could be quantified as 47.84 ± 0.44μM at c.d. of 10 mA cm-2. This value revealed a pos. dependence on electrolysis time, c.d., and anode potential. The effectiveness of ESR measurements was verified by the results obtained with the terephthalic acid probe. The ESR identification not only provides direct evidence for electro-generated •OH from a fundamental point of view, but also suggests a strategy to screen effective anode materials.
12贝，S.;你，S.;马，J.;陈旭;任，N.电生成羟基自由基的电子自旋共振证据。环境。Sci. Technol.2020， 54， 13333– 13343， DOI： 10.1021/acs.est.0c05287 - 13Wang, L.; Fu, Y.; Li, Q.; Wang, Z. EPR evidence for mechanistic diversity of Cu(II)/peroxygen oxidation systems by tracing the origin of DMPO spin adducts. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2022, 56, 8796– 8806, DOI: 10.1021/acs.est.2c00459 Google Scholar Google 学术搜索13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhtlCmtL%252FI&md5=7be225c7fe6079c92bd4901b412d88beEPR Evidence for Mechanistic Diversity of Cu(II)/Peroxygen Oxidation Systems by Tracing the Origin of DMPO Spin AdductsWang, Lingli; Fu, Yu; Li, Qingchao; Wang, ZhaohuiEnvironmental Science & Technology (2022), 56 (12), 8796-8806CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)ESR (EPR) has been extensively used for the identification of free radicals that are generated from advanced oxidn. processes (AOPs) so as to establish the reaction mechanism. However, some misinterpretations or controversies on the identity of detected EPR signals remain in the literature. This study, with Cu(II)-based AOPs as examples, comprehensively investigated the origin of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) adducts in Cu(II) alone, Cu(II)/H2O2, Cu(II)/peroxymonosulfate (PMS), and Cu(II)/peroxydisulfate (PDS) systems. In most Cu(II) systems, DMPO-OH signals can be detected even without any peroxygens, indicating the presence of other origins of this adduct in addn. to the genuine spin trapping of •OH by DMPO. According to the formed secondary radical adducts (DMPO-OCH3 from a nonradical process or DMPO-CH2OH from a radical oxidn.) derived from methanol quenching, we propose that CuO+, instead of free radicals, is involved in the Cu(II)/PMS system, while •OH is indeed generated in the Cu(II)/H2O2 and Cu(II)/PDS systems under neutral conditions. Notably, 17O-incorporation expts. demonstrate that -OH in the detected DMPO-OH adduct originates 100% from water in the Cu(II) alone system but the amt. of -OH is over 99.8% from the oxidant while peroxygens are added. In addn., DMPO-O2- appears only in the Cu(II)/PDS system under highly alk. conditions and H2O is not involved in superoxide formation.
13王L.;傅彦;李琦;Wang， Z.通过追踪DMPO自旋加合物的起源，为Cu（II）/过氧氧化体系的机理多样性提供EPR证据。环境。Sci. Technol.2022， 56， 8796– 8806， DOI： 10.1021/acs.est.2c00459 - 14Takahashi, M.; Shirai, Y.; Sugawa, S. Free-radical generation from bulk nanobubbles in aqueous electrolyte solutions: ESR spin-trap observation of microbubble-treated water. LangmuirIF 3.9SCIEJCI 0.67Q2化学2区2021, 37, 5005– 5011, DOI: 10.1021/acs.langmuir.1c00469 Google Scholar Google 学术搜索14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXoslShsr0%253D&md5=1290e6534556e6bb3f2e6550f2815e4bFree-Radical Generation from Bulk Nanobubbles in Aqueous Electrolyte Solutions: ESR Spin-Trap Observation of Microbubble-Treated WaterTakahashi, Masayoshi; Shirai, Yasuyuki; Sugawa, ShigetoshiLangmuir (2021), 37 (16), 5005-5011CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)Microbubbles are very fine bubbles that shrink and collapse when underwater within several minutes, leading to the generation of free radicals. ESR spectroscopy (ESR) confirmed the generation of hydroxyl radicals under strongly acidic conditions. The drastic environmental change caused by the collapse of the microbubbles may trigger radical generation via the dispersion of the elevated chem. potential that had accumulated around the gas-water interface. The present study also confirmed the generation of ESR signals from the microbubble-treated waters even after several months had elapsed following the dispersion of the microbubbles. Bulk nanobubbles were expected to be the source of the spin-adducts of hydroxyl radicals. Such microbubble stabilization and conversion might be caused by the formation of solid microbubble shells generated by iron ions in the condensed ionic cloud around the microbubble. Therefore, the addn. of a strong acid might cause drastic changes in the environment and destroy the stabilized condition. This would restart the collapsing process, leading to hydroxyl radical generation.
14高桥，M.;白井，Y.;Sugawa， S.水性电解质溶液中块状纳米气泡产生的自由基：微气泡处理水的ESR自旋阱观察。朗缪尔2021， 37， 5005– 5011， DOI： 10.1021/acs.langmuir.1c00469 - 15Kim, J.; Wang, J.; Ashley, D. C.; Sharma, V. K.; Huang, C.-H. Picolinic acid-mediated catalysis of Mn(II) for peracetic acid oxidation processes: Formation of high-valent Mn species. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2023, 57, 18929– 18939, DOI: 10.1021/acs.est.3c00765 Google Scholar Google 学术搜索15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhtVKnsLrF&md5=7df2e075d9eb6e8e54d5031e64dc5d46Picolinic Acid-Mediated Catalysis of Mn(II) for Peracetic Acid Oxidation Processes: Formation of High-Valent Mn SpeciesKim, Juhee; Wang, Junyue; Ashley, Daniel C.; Sharma, Virender K.; Huang, Ching-HuaEnvironmental Science & Technology (2023), 57 (47), 18929-18939CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)Metal-based advanced oxidn. processes (AOPs) with peracetic acid (PAA) have been extensively studied to degrade micropollutants (MPs) in wastewater. Mn(II) is a commonly used homogeneous metal catalyst for oxidant activation, but it performs poorly with PAA. This study identifies that the biodegradable chelating ligand picolinic acid (PICA) can significantly mediate Mn(II) activation of PAA for accelerated MP degrdn. Results show that, while Mn(II) alone has minimal reactivity toward PAA, the presence of PICA accelerates PAA loss by Mn(II). The PAA-Mn(II)-PICA system removes various MPs (methylene blue, bisphenol A, naproxen, sulfamethoxazole, carbamazepine, and trimethoprim) rapidly at neutral pH, achieving >60% removal within 10 min in clean and wastewater matrixes. Coexistent H2O2 and acetic acid in PAA play a negligible role in rapid MP degrdn. In-depth evaluation with scavengers and probe compds. (tert-Bu alc., methanol, Me Ph sulfoxide, and Me Ph sulfone) suggested that high-valent Mn species (Mn(V)) is a likely main reactive species leading to rapid MP degrdn., whereas sol. Mn(III)-PICA and radicals (CH3C(O)O• and CH3C(O)OO•) are minor reactive species. This study broadens the mechanistic understanding of metal-based AOPs using PAA in combination with chelating agents and indicates the PAA-Mn(II)-PICA system as a novel AOP for wastewater treatment.
15金，J.;王军;阿什利，哥伦比亚特区;夏尔马，VK;Huang， C.-H.吡啶甲酸介导的 Mn（II） 催化过氧乙酸氧化过程：高价 Mn 物种的形成。环境。Sci. Technol.2023， 57， 18929– 18939， DOI： 10.1021/acs.est.3c00765 - 16Zong, Y.; Guan, X.; Xu, J.; Feng, Y.; Mao, Y.; Xu, L.; Chu, H.; Wu, D. Unraveling the overlooked involvement of high-valent cobalt-oxo species generated from the cobalt(II)-activated peroxymonosulfate process. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2020, 54, 16231– 16239, DOI: 10.1021/acs.est.0c06808 Google Scholar Google 学术搜索16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitlyisrbP&md5=100e978728a5ae1e13de52556553efcfUnraveling the Overlooked Involvement of High-Valent Cobalt-Oxo Species Generated from the Cobalt(II)-Activated Peroxymonosulfate ProcessZong, Yang; Guan, Xiaohong; Xu, Jun; Feng, Yong; Mao, Yunfeng; Xu, Longqian; Chu, Huaqiang; Wu, DeliEnvironmental Science & Technology (2020), 54 (24), 16231-16239CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Sulfate radical (SO4•-) is widely recognized as the predominant species generated from the cobalt(II)-activated peroxymonosulfate (PMS) process. However, in this study, it was surprisingly found that Me Ph sulfoxide (PMSO) was readily oxidized to the corresponding sulfone (PMSO2) with a transformation ratio of ~ 100% under acidic conditions, which strongly implied the generation of high-valent cobalt-oxo species [Co(IV)] instead of SO4•- in the Co(II)/PMS process. Scavenging expts. using methanol (MeOH), tert-Bu alc., and DMSO further suggested the negligible role of SO4•- and hydroxyl radical (•OH) but favored the generation of Co(IV). By employing 18O isotope-labeling technique, the formation of Co(IV) was conclusively verified and the oxygen atom exchange reaction between Co(IV) and H2O was revealed. D. functional theory calcn. detd. that the formation of Co(IV) was thermodynamically favorable than that of SO4•- and •OH in the Co(II)/PMS process. The generated Co(IV) species was indicated to be highly reactive due to the existence of oxo-wall and capable of oxidizing the org. pollutant that is rather recalcitrant to SO4•- attack, for example, nitrobenzene. Addnl., the degrdn. intermediates of sulfamethoxazole (SMX) in the Co(II)/PMS process under acidic conditions were identified to further understand the interaction between Co(IV) and the representative contaminant. The developed kinetic model successfully simulated PMSO loss, PMSO2 prodn., SMX degrdn., and/or PMS decompn. under varying conditions, which further supported the proposed mechanism. This study might shed new light on the Co(II)/PMS process.
16宗Y.;关晓 X.;徐军;冯，Y.;毛，Y.;徐玲;朱，H.;揭开钴（II）活化的过氧单硫酸盐工艺产生的高价钴氧基物质被忽视的参与。环境。Sci. Technol.2020， 54， 16231– 16239， DOI： 10.1021/acs.est.0c06808 - 17Hu, C.-H.; Kim, S.-T.; Baik, M.-H.; Mirica, L. M. Nickel–carbon bond oxygenation with green oxidants via high-valent nickel species. J. Am. Chem. Soc.IF 15.0SCIEJCI 2.63Q1化学1区Top2023, 145, 11161– 11172, DOI: 10.1021/jacs.3c01012 Google Scholar Google 学术搜索17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXpvVOit70%253D&md5=f033852508bd14dcf701b2590f565337Nickel-Carbon Bond Oxygenation with Green Oxidants via High-Valent Nickel SpeciesHu, Chi-Herng; Kim, Seoung-Tae; Baik, Mu-Hyun; Mirica, Liviu M.Journal of the American Chemical Society (2023), 145 (20), 11161-11172CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)Described herein is the synthesis of the NiII complex (tBuMe2tacn)NiII(cycloneophyl) (tBuMe2tacn = 1-tert-butyl-4,7-dimethyl-1,4,7-triazacyclononane, cycloneophyl = -CH2CMe2-o-C6H4-) and its reactivity with dioxygen and peroxides. The new tBuMe2tacn ligand is designed to enhance the oxidatively induced bond-forming reactivity of high-valent Ni intermediates. Tunable chemoselectivity for Csp2-O vs Csp2-Csp3 bond formation was achieved by selecting the appropriate solvent and reaction conditions. Importantly, the use of cumene hydroperoxide and meta-chloroperbenzoic acid suggests a heterolytic O-O bond cleavage upon reaction with (tBuMe2tacn)NiII(cycloneophyl). Mechanistic studies using isotopically labeled H2O2 support the generation of a high-valent Ni-oxygen species via an inner-sphere mechanism and subsequent reductive elimination to form the Csp2-O bond. Kinetic studies of the exceptionally fast Csp2-O bond-forming reaction reveal a first-order dependence on both (tBuMe2tacn)NiII(cycloneophyl) and H2O2, and thus an overall second-order reaction. Eyring anal. further suggests that the oxidn. of the NiII complex by H2O2 is the rate-detg. step, which can be modulated by the presence of coordinating solvents. Moreover, computational studies fully support the conclusions drawn from exptl. results. Overall, this study reveals for the first time the ability to control the oxidatively induced C-C vs C-O bond formation reactions at a Ni center. Importantly, the described system merges the known organometallic reactivity of Ni with the biomimetic oxidative transformations resembling oxygenases and peroxidases, and involving high-valent metal-oxygen intermediates, which is a novel approach that should lead to unprecedented oxidative catalytic transformations.
17胡，C.-H.;金，S.-T.;白克，M.-H.;Mirica， L. M.通过高价镍物种与绿色氧化剂进行镍-碳键氧化。化学学报.2023， 145， 11161– 11172， DOI： 10.1021/jacs.3c01012 - 18Walling, S. A.; Um, W.; Corkhill, C. L.; Hyatt, N. C. Fenton and Fenton-like wet oxidation for degradation and destruction of organic radioactive wastes. npj Mater. Degrad.IF 5.1SCIEJCI 0.85Q2材料科学2区2021, 5, 50, DOI: 10.1038/s41529-021-00192-3 Google Scholar Google 学术搜索There is no corresponding record for this reference.
18Walling， S.A.;嗯，W.;科克希尔，CL;Hyatt， N. C.Fenton 和 Fenton 类湿氧化用于降解和破坏有机放射性废物。npj Mater.Degrad.2021， 5， 50， DOI： 10.1038/s41529-021-00192-3 - 19Shang, Y.; Xu, X.; Gao, B.; Wang, S.; Duan, X. Single-atom catalysis in advanced oxidation processes for environmental remediation. Chem. Soc. Rev.IF 46.2SCIEJCI 3.41Q1化学1区Top2021, 50, 5281– 5322, DOI: 10.1039/D0CS01032D Google Scholar Google 学术搜索19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXotFKjsbk%253D&md5=e552e57b5dc3de848e82867c8bce4bddSingle-atom catalysis in advanced oxidation processes for environmental remediationShang, Yanan; Xu, Xing; Gao, Baoyu; Wang, Shaobin; Duan, XiaoguangChemical Society Reviews (2021), 50 (8), 5281-5322CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)A review. Emerging single atom catalysts (SACs), esp. carbon-based SACs are appealing materials in environmental catalysis because of their ultrahigh performances, environmental friendliness, structural/chem. robustness, and the max. utilization of active metal sites. The metal centers, carbon matrixes, and coordination characteristics collectively det. the electronic features of carbon-based SACs, and their behaviors in catalyzing peroxide activation and efficiencies in advanced oxidn. processes (AOPs). However, there is lack of a comprehensive and crit. review reporting the successful marriage of carbon-based SACs in AOP-based remediation technologies. It is particularly necessary to systematically compare and reveal the catalytic sites and the assocd. mechanisms of carbon-based SACs in diverse AOP systems. In this review, we highlight the synthetic strategies, characterization, and computation of carbon-based SACs, and for the first time, showcase their innovative applications in AOP technologies. We unveil the origins of versatile catalytic oxidn. pathways in different AOP systems and the mechanisms of micropollutant degrdn. over carbon-based SACs, distinguished from the upsized counterparts (metals/oxides and carbon substrates). We also provide directions to the rational design of on-demand SACs for green chem. and environmental sustainability. Also, we suggest a designated and integrated exptl./theor. protocol for revealing the structure-catalysis relations of SACs in AOP applications, and propose the prospects for future opportunities and challenges.
19尚，Y.;徐旭;高，B.;王，S.;Duan， X.单原子催化在高级氧化工艺中的环境修复.Chem. Soc. Rev.2021， 50， 5281– 5322， DOI： 10.1039/D0CS01032D - 20Li, Y.; Dong, H.; Li, L.; Tang, L.; Tian, R.; Li, R.; Chen, J.; Xie, Q.; Jin, Z.; Xiao, J.; Xiao, S.; Zeng, G. Recent advances in waste water treatment through transition metal sulfides-based advanced oxidation processes. Water Res.IF 12.8SCIEJCI 2.15Q1环境科学与生态学1区Top2021, 192, 116850, DOI: 10.1016/j.watres.2021.116850 Google Scholar Google 学术搜索20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXitVamtb4%253D&md5=b1a494b8c1608c5c7ff6fae0a0841cadRecent advances in waste water treatment through transition metal sulfides-based advanced oxidation processesLi, Yangju; Dong, Haoran; Li, Long; Tang, Lin; Tian, Ran; Li, Rui; Chen, Jie; Xie, Qianqian; Jin, Zilan; Xiao, Junyang; Xiao, Shuangjie; Zeng, GuangmingWater Research (2021), 192 (), 116850CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)A review. With the ever-growing water pollution issues, advanced oxidn. processes (AOPs) have received growing attention due to their high efficiency in the removal of refractory org. pollutants. Transition metal sulfides (TMSs), with excellent optical, elec., and catalytical performance, are of great interest as heterogeneous catalysts. These TMSs-based heterogeneous catalysts have been demonstrated to becapable and adaptable in water purifn. through advanced oxidn. processes. The aim of this review is to conduct an exhaustive anal. and summary of recent progress in the application of TMSs-based AOPs for water decontamination. Firstly, the commonly used tuning strategies for TMSs-based catalysts are concisely introduced, including artificial size and shape control, compn. control, doping, and heterostructure manufg. Then, a comprehensive overview of the current state-of-the-art progress on TMSs-based AOPs (i.e., Fenton-like oxidn., photocatalytic oxidn., and electro chem. oxidn. processes) for wastewater treatment is discussed in detail, with an emphasis on their catalytic performance and involved mechanism. In addn., influencing factors of water chem., namely, pH, temp., dissolved oxygen, inorg. species, and natural org. matter on the catalytic performance of established AOPs are analyzed. Furthermore, the reusability and stability of TMSs-based catalysts in these AOPs are also outlined. Finally, current challenges and future perspectives related to TMSs-based catalysts and their applications for AOPs wastewater treatment are proposed. It is expected that this review would shed some light on the future development of TMSs-based AOPs towards water purifn.
20李Y.;董，H.;李，L.;唐，L.;田，R.;李，R.;陈军;谢清;金，Z.;肖，J.;肖，S.;Zeng， G.基于过渡金属硫化物的先进氧化工艺处理废水的最新进展.水资源研究 2021， 192， 116850， DOI： 10.1016/j.watres.2021.116850 - 21Huang, M.; Han, Y.; Xiang, W.; Zhong, D.; Wang, C.; Zhou, T.; Wu, X.; Mao, J. In situ-formed phenoxyl radical on the CuO surface triggers efficient persulfate activation for phenol degradation. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2021, 55, 15361– 15370, DOI: 10.1021/acs.est.1c03758 Google Scholar Google 学术搜索21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXitlSltrzE&md5=725329e2b1f8ba58e1c7d24751d00b88In Situ-Formed Phenoxyl Radical on the CuO Surface Triggers Efficient Persulfate Activation for Phenol DegradationHuang, Mingjie; Han, Yi; Xiang, Wei; Zhong, Delai; Wang, Chen; Zhou, Tao; Wu, Xiaohui; Mao, JuanEnvironmental Science & Technology (2021), 55 (22), 15361-15370CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)Transition-metal oxide (MxOy)-based persulfate (PDS) activation processes have demonstrated enormous potential for pollutant degrdn. in water purifn. However, the mechanistic insight of PDS activation by a MxOy catalyst concerning the mediate role of the org. substrate remains obscure. Here, we demonstrated that the in situ-formed phenoxyl radical on the CuO surface can trigger efficient persulfate activation for phenol degrdn. The formation of the phenoxyl radical was an inner-sphere process, which involved the successive steps of chemisorption through surface hydroxyl group substitution and the subsequent spontaneous electron transfer reaction from adsorbed phenol to CuO. The org. substrate phenol can be oxidized by the PDS mol. and surface-bound SO4•- through the nonradical and free-radical pathways, resp. Such a unique "half-radical" mechanism resulted in an extraordinarily high PDS utilization efficiency of 188.9%. More importantly, a general rule for phenoxyl radical formation was concluded; it can be formed in the cases of org. substrates with a Hammett const. σ+ lower than -0.02 and metal ion of a 3d subshell between half-filled and fully filled. This study clarifies the mediate role of the org. substrate for interfacial PDS activation on MxOy and also gives new insights into the rational design of a highly efficient MxOy catalyst for selective phenolic/aniline pollutant degrdn. in wastewater.
21黄，M.;韩Y.;向，W.;钟博士;王，C.;周，T.;吴X.;毛，CuO 表面 J.In 原位形成的苯氧基自由基会触发有效的过硫酸盐活化以降解苯酚。环境。Sci. Technol.2021， 55， 15361– 15370， DOI： 10.1021/acs.est.1c03758 - 22Vencalek, B. E.; Laughton, S. N.; Spielman-Sun, E.; Rodrigues, S. M.; Unrine, J. M.; Lowry, G. V.; Gregory, K. B. In situ measurement of CuO and Cu(OH)2 nanoparticle dissolution rates in quiescent freshwater mesocosms. Environ. Sci. Technol. Lett.IF 10.9SCIEJCI 1.42Q1环境科学与生态学2区2016, 3, 375– 380, DOI: 10.1021/acs.estlett.6b00252 Google Scholar Google 学术搜索22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtlOqtb3N&md5=91d2b6a471e80353a49d5259122541d4In Situ Measurement of CuO and Cu(OH)2 Nanoparticle Dissolution Rates in Quiescent Freshwater MesocosmsVencalek, Brian E.; Laughton, Stephanie N.; Spielman-Sun, Eleanor; Rodrigues, Sonia M.; Unrine, Jason M.; Lowry, Gregory V.; Gregory, Kelvin B.Environmental Science & Technology Letters (2016), 3 (10), 375-380CODEN: ESTLCU; ISSN:2328-8930. (American Chemical Society)Recent studies have characterized Cu-based nanoparticles (CBNPs) as relatively insol., raising potential persistence, accumulation, and toxicol. concerns about their long-term application as agricultural pesticides. The dissoln. rates of 2 CBNPs were measured in natural and artificial waters under both satd. and unsatd. conditions with respect to CuO(s) (total Cu, <1 mg/Kg). Kocide 3000, an agricultural pesticide formulation with nanoscale Cu(OH)2 particles, rapidly dissolved with an exptl. half-life of <8 h in natural water. Cu oxide nanoparticles were longer-lived, with an exptl. half-life of 73 h in natural water. In contrast to prior reports of CuONP dissoln., our results suggest that even in moderately alk. waters, CuO and Cu(OH)2 NPs may persist as particles for days to weeks under quiescent conditions in a freshwater environment.
22文卡莱克，B.E.;劳顿，S.N.;斯皮尔曼-孙，E.;罗德里格斯，SM;安莱恩，JM;洛瑞，G.V.;Gregory， K. B.In 静态淡水中层中 CuO 和 Cu（OH） 2 纳米颗粒溶解速率的原位测量。环境。Sci. Technol. Lett.2016， 3， 375– 380， DOI： 10.1021/acs.estlett.6b00252 - 23Zhao, Z.; Peng, S.; Ma, C.; Yu, C.; Wu, D. Redox behavior of secondary solid iron species and the corresponding effects on hydroxyl radical generation during the pyrite oxidation process. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2022, 56, 12635– 12644, DOI: 10.1021/acs.est.2c04624 Google Scholar Google 学术搜索23https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitFelsL7K&md5=0eac48e135d1383145fa29264d3e9362Redox behavior of secondary solid iron species and the corresponding effects on hydroxyl radical generation during the pyrite oxidation processZhao, Zhenyu; Peng, Shuai; Ma, Canming; Yu, Chao; Wu, DeliEnvironmental Science & Technology (2022), 56 (17), 12635-12644CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)During the pyrite oxidn. process, aq. ferrous/ferric ions (Fe2+/Fe3+), as well as surface-adsorbed Fe2+/Fe3+, have been widely recognized to dominate hydroxyl radical (•OH) generation, while this study reveals that the secondary solid iron species also play non-negligible roles. Based on the different forms and the presence of sites, the secondary solid iron species were classified as Fecoat (iron-contg. coating on the pyrite surface) and Fedep (ex situ-deposited iron (oxyhydr)oxide that is not in contact with pyrite). Instead of participating in building a stubborn passivation layer on the pyrite surface, Fecoat is easy to fall off from the pyrite surface as the oxidn. of pyrite deepens, while large fractions of Fedep and Fecoat are found to be extractable with nitrilotriacetic acid (NTA). Achieved by cyclically oxidizing pyrite within different NTA levels (0/0.1/10 mM), Fecoat and Fedep were proved to have distinct redox behavior during the pyrite oxidn. process. Amorphous Fedep, originated from the hydrolyzation of dissolved Fe3+, accelerates the nonradical decay of hydrogen peroxide (H2O2); as a result, the accumulation of Fedep always decreases the •OH prodn. during the pyrite oxidn. process. However, part of Fedep adsorbs on the pyrite surface through electrostatic attraction and converts into Fecoat. The electron conduction between Fecoat and pyrite was verified, which accelerates the oxidative dissoln. of pyrite, produces reactive Fe(II), and therefore favors •OH generation. This study improves our understanding of the redox behavior of pyrite in complex media such as natural processes and practical engineering systems.
23赵志强;彭，S.;马，C.;俞，C.;二次固体铁物种的氧化还原行为及其对黄铁矿氧化过程中羟基自由基生成的相应影响.环境。Sci. Technol.2022， 56， 12635– 12644， DOI： 10.1021/acs.est.2c04624 - 24Stoll, S.; Schweiger, A. EasySpin, a comprehensive software package for spectral simulation and analysis in EPR. J. Magn. Reson.IF 2.2SCIEJCI 0.74Q3化学3区2006, 178, 42– 55, DOI: 10.1016/j.jmr.2005.08.013 Google Scholar Google 学术搜索24https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXht12it7bE&md5=2fffe78f07a39f44fa3279a64e68b5d3EasySpin, a comprehensive software package for spectral simulation and analysis in EPRStoll, Stefan; Schweiger, ArthurJournal of Magnetic Resonance (2006), 178 (1), 42-55CODEN: JMARF3; ISSN:1090-7807. (Elsevier)EasySpin, a computational package for spectral simulation and anal. in EPR, is described. It is based on Matlab, a com. tech. computation software. EasySpin provides extensive EPR-related functionality, ranging from elementary spin physics to data anal. It provides routines for the simulation of liq.- and solid-state EPR and ENDOR spectra. These simulation functions are built on novel algorithms that enhance scope, speed and accuracy of spectral simulations. Spin systems with an arbitrary no. of electron and nuclear spins are supported. The structure of the toolbox as well as the theor. background underlying its simulation functionality are presented, and some illustrative examples are given.
24斯托尔，S.;Schweiger， A.EasySpin，用于 EPR 光谱模拟和分析的综合软件包。J.马格。Reson.2006， 178， 42– 55， DOI： 10.1016/j.jmr.2005.08.013 - 25Huang, M.; Li, Y.-S.; Zhang, C.-Q.; Cui, C.; Huang, Q.-Q.; Li, M.; Qiang, Z.; Zhou, T.; Wu, X.; Yu, H.-Q. Facilely tuning the intrinsic catalytic sites of the spinel oxide for peroxymonosulfate activation: From fundamental investigation to pilot-scale demonstration. Proc. Natl. Acad. Sci. U.S.A.IF 11.1SCIEJCI 2.52Q1综合性期刊1区Top2022, 119, e2202682119, DOI: 10.1073/pnas.2202682119 Google Scholar Google 学术搜索There is no corresponding record for this reference.
25黄，M.;李永胜;张志清;崔，C.;黄Q.-Q.;李，M.;强，Z.;周，T.;吴X.;Yu， H.-Q.Facilely tuneting the intrinsic catalytic sites of the spinelic oxide for peroxymonosulfate activation： From fundamental investigation to pilot-scale demonstration.美国国家科学院院刊 2022， 119， e2202682119， DOI： 10.1073/pnas.2202682119 - 26Chen, L.; Duan, J.; Du, P.; Sun, W.; Lai, B.; Liu, W. Accurate identification of radicals by in-situ electron paramagnetic resonance in ultraviolet-based homogenous advanced oxidation processes. Water Res.IF 12.8SCIEJCI 2.15Q1环境科学与生态学1区Top2022, 221, 118747, DOI: 10.1016/j.watres.2022.118747 Google Scholar Google 学术搜索26https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhsFChsrbO&md5=7d062c7ebe3d08747d8fafd83c2117b4Accurate identification of radicals by in-situ electron paramagnetic resonance in ultraviolet-based homogenous advanced oxidation processesChen, Long; Duan, Jun; Du, Penghui; Sun, Weiliang; Lai, Bo; Liu, WenWater Research (2022), 221 (), 118747CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Accurate identification of radicals in advanced oxidn. processes (AOPs) is important to study the mechanisms on radical prodn. and subsequent oxidn.-redn. reaction. The commonly applied radical quenching expts. cannot provide direct evidences on generation and evolution of radicals in AOPs, while ESR (EPR) is a cutting-edge technol. to identify radicals based on spectral characteristics. However, the complexity of EPR spectrum brings uncertainty and inconsistency to radical identification and mechanism clarification. This work presented a comprehensive study on identification of radicals by in-situ EPR anal. in four typical UV-based homogenous AOPs, including UV/H2O2, UV/peroxodisulfate (and peroxymonosulfate), UV/peracetic acid and UV/IO-4 systems. Radical formation mechanism was also clarified based on EPR results. A reliable EPR method using org. solvents was proposed to identify alkoxy and alkyl radicals (CH3C(=O)OO·, CH3C(=O)O· and ·CH3) in UV/PAA system. Two activation pathways for radical prodn. were proposed in UV/IO-4 system, in which the produced IO3·, IO4·, ·OH and hydrated electron were precisely detected. It is interesting that addn. of specific org. solvents can effectively identify oxygen-center and carbon-center radicals. A key parameter in EPR spectrum for 5,5-dimethyl-1-pyrroline N-oxide (DMPO) spin adduct, AH, is ranked as: ·CH3 (23 G) >·OH (15 G) >IO3· (12.9 G) >O2·- (11 G) ≥·OOH (9-11 G) ≥IO4· (9-10 G) ≥SO4·- (9-10 G) >CH3C(=O)OO· (8.5 G) > CH3C(=O)O· (7.5 G). This study will give a systematic method on identification of radicals in AOPs, and shed light on the insightful understanding of radical prodn. mechanism.
26陈，L.;段杰;杜，P.;孙，W.;赖，B.;Liu， W.在紫外线均相高级氧化过程中通过原位电子顺磁共振准确识别自由基.水资源研究 2022， 221， 118747， DOI： 10.1016/j.watres.2022.118747 - 27Dou, J.; Cheng, J.; Lu, Z.; Tian, Z.; Xu, J.; He, Y. Biochar co-doped with nitrogen and boron switching the free radical based peroxydisulfate activation into the electron-transfer dominated nonradical process. Appl. Catal., BIF 22.1SCIEJCI 3.14Q1化学1区Top2022, 301, 120832, DOI: 10.1016/j.apcatb.2021.120832 Google Scholar Google 学术搜索27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXit1ygt7%252FK&md5=7fa8cf474c42b508ad15b2de646ebf48Biochar co-doped with nitrogen and boron switching the free radical based peroxydisulfate activation into the electron-transfer dominated nonradical processDou, Jibo; Cheng, Jie; Lu, Zhijiang; Tian, Ziqi; Xu, Jianming; He, YanApplied Catalysis, B: Environmental (2022), 301 (), 120832CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)In this study, N/B co-doped biochars were employed as metal-free activators of peroxydisulfate (PDS) for tetracycline degrdn., more importantly, the roles of dopants and the relative contribution of radical vs nonradical oxidns. were comprehensively investigated. Integrating with ESR and kinetics calcns., we showed that co-doping N and B into biochars not only boosted the catalytic activity but also switched the radical PDS-activated process into the electron transfer-dominated nonradical process. Compared with pristine biochar/PDS systems (22%), the nonradical contribution of N/B co-doped biochar/PDS systems increased to 59%, exhibiting outstanding stability and selectivity. Galvanic oxidn. tests and theor. simulations unveiled that doped biochars as conductive tunnels accelerate the p.d.-driven electron transfer from the HOMO of pollutants to the LUMO of PDS due to the lower energy gap. This study provided new insights into the crit. role of heteroatom-doped carbocatalysts in PDS nonradical activation.
27窦，J.;程杰;卢志强;田志强;徐军;He， Y.Biochar 与氮和硼共掺杂，将基于自由基的过氧二硫酸盐活化转变为电子转移主导的非自由基过程。应用催化， B2022， 301， 120832， DOI： 10.1016/j.apcatb.2021.120832 - 28Zhu, L.; Ji, J.; Liu, J.; Mine, S.; Matsuoka, M.; Zhang, J.; Xing, M. Designing 3D-MoS2 sponge as excellent cocatalysts in advanced oxidation processes for pollutant control. Angew. Chem., Int. Ed.IF 16.6SCIEJCI 2.6Q1化学1区Top2020, 59, 13968– 13976, DOI: 10.1002/anie.202006059 Google Scholar Google 学术搜索28https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtV2ktbvP&md5=c6ac477c0ec686707da101913e619aaeDesigning 3D MoS2 sponge as cocatalysts in advanced oxidation processes for pollution controlZhu, Lingli; Ji, Jiahui; Liu, Jun; Mine, Shinya; Matsuoka, Masaya; Zhang, Jinlong; Xing, MingyangAngewandte Chemie, International Edition (2020), 59 (33), 13968-13976CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)3D-MoS2 can adsorb org. mols. and provide multidimensional electron transport pathways, implying a potential application for environmental remediation. Here, we study the degrdn. of arom. orgs. in advanced oxidn. processes (AOPs) by a 3D-MoS2 sponge loaded with MoS2 nanospheres and graphene oxide (GO). Exposed Mo4+ active sites on 3D-MoS2 can significantly improve the concn. and stability of Fe2+ in AOPs and keep the Fe3+/Fe2+ in a stable dynamic cycle, thus effectively promoting the activation of H2O2/peroxymonosulfate (PMS). The degrdn. rate of org. pollutants in the 3D-MoS2 system is about 50 times higher than without cocatalyst. After a 140 L pilot-scale expt., it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D-MoS2 achieves a degrdn. rate of 120 mg L-1 antibiotic wastewater up to 97.87%. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications.
28朱玲玲;姬军;刘军;我的，S.;松冈，M.;张军;Xing， M.设计3D-MoS 2 海绵作为高级氧化工艺中用于污染物控制的优良助催化剂。昂热。Chem.， Int. Ed.2020， 59， 13968– 13976， DOI： 10.1002/anie.202006059 - 29Yi, Q.; Li, X.; Li, Y.; Dai, R.; Wang, Z. Unraveling the Co(IV)-mediated oxidation mechanism in a Co3O4/PMS-based hierarchical reactor: Toward efficient catalytic degradation of aromatic pollutants. ACS EST Engg. 2022, 2, 1836– 1846, DOI: 10.1021/acsestengg.2c00087 Google Scholar Google 学术搜索There is no corresponding record for this reference.
29易Q.;李旭;李勇;戴，R.;Unraveling the Co（IV）-mediadated oxidation mechanism in a Co 3 O 4 /PMS-based hierarchical rearchical reactorants： Towards efficient catalytic degradation of aromatic pollutants.ACS EST Engg.2022， 2， 1836– 1846， DOI： 10.1021/acsestengg.2c00087 - 30Niu, L.; Lin, J.; Chen, W.; Zhang, Q.; Yu, X.; Feng, M. Ferrate(VI)/periodate system: Synergistic and rapid oxidation of micropollutants via periodate/iodate-modulated Fe(IV)/Fe(V) intermediates. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2023, 57, 7051– 7062, DOI: 10.1021/acs.est.2c08965 Google Scholar Google 学术搜索30https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXotVWhtrk%253D&md5=da496d6dd1e9f1b1c1efdb0dffd8ccccFerrate(VI)/Periodate System: Synergistic and Rapid Oxidation of Micropollutants via Periodate/Iodate-Modulated Fe(IV)/Fe(V) IntermediatesNiu, Lijun; Lin, Jiang; Chen, Wenzheng; Zhang, Qian; Yu, Xin; Feng, MingbaoEnvironmental Science & Technology (2023), 57 (17), 7051-7062CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)The presence of org. micropollutants in water sources worldwide has created a need for the development of effective and selective oxidn. methods in complex water matrixes. This study is the first report of the combination of ferrate(VI) (Fe(VI)) and periodate (PI) for synergistic, rapid, and selective elimination of multiple micropollutants. This combined system was found to outperform other Fe(VI)/oxidant systems (e.g., H2O2, peroxydisulfate, and peroxymonosulfate) in rapid water decontamination. Scavenging, probing, and ESR expts. showed that high-valent Fe(IV)/Fe(V) intermediates, rather than hydroxyl radicals, superoxide radicals, singlet oxygen, and iodyl radicals, played a dominant role in the process. Further, the generation of Fe(IV)/Fe(V) was evidenced directly by the 57Fe M.ovrddot.ossbauer spectroscopic test. Surprisingly, the reactivity of PI toward Fe(VI) is rather low (0.8223 M-1 s-1) at pH 8.0, implying that PI was not acting as an activator. Besides, as the only iodine sink of PI, iodate also played an enhanced role in micropollutant abatement by Fe(VI) oxidn. Further expts. proved that PI and/or iodate might function as the Fe(IV)/Fe(V) ligands, causing the utilization efficiency of Fe(IV)/Fe(V) intermediates for pollutant oxidn. to outcompete their auto-decompn. Finally, the oxidized products and plausible transformation pathways of three different micropollutants by single Fe(VI) and Fe(VI)/PI oxidn. were characterized and elucidated. Overall, this study proposed a novel selective oxidn. strategy (i.e., Fe(VI)/PI system) that could efficiently eliminate water micropollutants and clarified the unexpected interactions between PI/iodate and Fe(VI) for accelerated oxidn.
30牛，L.;林杰;陈，W.;张琦;俞旭;Feng， M.Ferrate（VI）/Oxiate System：通过高碘酸盐/碘酸盐调节的Fe（IV）/Fe（V）中间体对微污染物进行协同和快速氧化。环境。Sci. Technol.2023， 57， 7051– 7062， DOI： 10.1021/acs.est.2c08965 - 31Cai, P.; Zhao, J.; Zhang, X.; Zhang, T.; Yin, G.; Chen, S.; Dong, C.-L.; Huang, Y.-C.; Sun, Y.; Yang, D.; Xing, B. Synergy between cobalt and nickel on NiCo2O4 nanosheets promotes peroxymonosulfate activation for efficient norfloxacin degradation. Appl. Catal., BIF 22.1SCIEJCI 3.14Q1化学1区Top2022, 306, 121091, DOI: 10.1016/j.apcatb.2022.121091 Google Scholar Google 学术搜索31https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhvFGitL4%253D&md5=cf0ea4459f215345ea10db8c2b8efa02Synergy between cobalt and nickel on NiCo2O4 nanosheets promotes peroxymonosulfate activation for efficient norfloxacin degradationCai, Pengcheng; Zhao, Jian; Zhang, Xiaohui; Zhang, Tianyu; Yin, Guiming; Chen, Shuai; Dong, Chung-Li; Huang, Yu-Cheng; Sun, Yuanyuan; Yang, Dongjiang; Xing, BaoshanApplied Catalysis, B: Environmental (2022), 306 (), 121091CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)Developing an ultraefficient heterogeneous catalyst for peroxymonosulfate (PMS) activation at a wide pH range is a challenge. Herein, ultrathin NiCo2O4 nanosheets (NiCo2O4NS, ∼1 nm), with the dominant exposure of (311) facet, was designed for PMS activation. The NiCo2O4NS/PMS system exhibited superior degrdn. of norfloxacin (NOR) over a wide pH range. The synergistic effects between Ni and Co were the dominant activation mechanism. Compared with Co3O4, NiCo2O4NS adsorb PMS through a unique "bridge" mode, where both Co and adjacent Ni interact with the same O atom in PMS, increasing the no. of electron transfer for enhanced breakage of O-O bond. NiCo2O4NS with high cycling stability, could reach 100% degrdn. of other typical pollutants, and showed higher degrdn. performance in actual wastewater. This work unveils the intrinsic origin of the superior activity of Co-Ni spinel oxides for PMS activation for the first time, and demonstrates its application potential for org. contaminants degrdn.
31蔡，P.;赵杰;张X.;张T.;尹国;陈，S.;董，C.-L.;黄永昌;孙，Y.;杨博士;钴和镍在NiCo 2 O 4 纳米片上的协同作用促进了过氧单硫酸盐的活化，从而有效地降解了诺氟沙星。应用催化， B2022， 306， 121091， DOI： 10.1016/j.apcatb.2022.121091 - 32Wang, Y.; Sun, H.; Ang, H. M.; Tadé, M. O.; Wang, S. 3D-hierarchically structured MnO2 for catalytic oxidation of phenol solutions by activation of peroxymonosulfate: Structure dependence and mechanism. Appl. Catal., BIF 22.1SCIEJCI 3.14Q1化学1区Top2015, 164, 159– 167, DOI: 10.1016/j.apcatb.2014.09.004 Google Scholar Google 学术搜索32https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsFOqtr3M&md5=0cda9a7a07a4f5ca98f754cbc8c14f3d3D-hierarchically structured MnO2 for catalytic oxidation of phenol solutions by activation of peroxymonosulfate: Structure dependence and mechanismWang, Yuxian; Sun, Hongqi; Ang, Ha Ming; Tade, Moses O.; Wang, ShaobinApplied Catalysis, B: Environmental (2015), 164 (), 159-167CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)Hierarchical materials have facilitated fascinating applications in heterogeneous catalysis due to that micro-sized bulk is easily separable and nano-sized sub-blocks can significantly enhance catalytic performance. In this study, corolla-like δ-MnO2 with sub-blocks of nanosheets, and urchin-shaped α-MnO2 with sub-blocks of nanorods were synthesized by a simple hydrothermal route. The hydrothermal temp. significantly influenced the crystal structure, morphol. and textural structure of the obtained three-dimensional (3D) MnO2 catalysts. The catalytic activities of three samples prepd. at 60, 100 and 110 °C (denoted as Mn-60, -100 and -110, resp.) were thoroughly evaluated by activation of peroxymonosulfate (PMS) for catalytic oxidn. of phenol solns. Based on first-order kinetics, the rate consts. of Mn-60, -100 and -110 catalysts were detd. to be 0.062, 0.132, and 0.075 min-1, resp. The activation energy of Mn-100 in catalytic oxidn. of phenol solns. was estd. to be 25.3 kJ/mol. The catalytic stability of Mn-100 was also tested and discussed by monitoring Mn leaching. ESR (EPR), quenching tests, total org. carbon (TOC) anal. and identification of intermediates were applied to illustrate the activation processes of PMS and the mechanism of phenol degrdn.
32王永;孙，H.;洪，HM;塔德，M.O.;Wang，S.3D分层结构的MnO 2 通过活化过氧单硫酸盐催化氧化苯酚溶液：结构依赖性和机理。应用催化， B2015， 164， 159– 167， DOI： 10.1016/j.apcatb.2014.09.004 - 33Kottapurath Vijay, A.; Marks, V.; Mizrahi, A.; Wen, Y.; Ma, X.; Sharma, V. K.; Meyerstein, D. Reaction of FeaqII with peroxymonosulfate and peroxydisulfate in the presence of bicarbonate: Formation of FeaqIV and carbonate radical anions. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2023, 57, 6743– 6753, DOI: 10.1021/acs.est.3c00182 Google Scholar Google 学术搜索33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXns1SisLs%253D&md5=c95ee75244f86f41bea80b811df834a9Reaction of FeaqII with Peroxymonosulfate and Peroxydisulfate in the Presence of Bicarbonate: Formation of FeaqIV and Carbonate Radical AnionsKottapurath Vijay, Aswin; Marks, Vered; Mizrahi, Amir; Wen, Yinghao; Ma, Xingmao; Sharma, Virender K.; Meyerstein, DanEnvironmental Science & Technology (2023), 57 (16), 6743-6753CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)Many advanced oxidn. processes (AOPs) use Fenton-like reactions to degrade org. pollutants by activating peroxymonosulfate (HSO5-, PMS) or peroxydisulfate (S2O82-, PDS) with Fe(H2O)62+ (FeaqII). This paper presents results on the kinetics and mechanisms of reactions between FeaqII and PMS or PDS in the absence and presence of bicarbonate (HCO3-) at different pH. In the absence of HCO3-, FeaqIV, rather than the commonly assumed SO4•-, is the dominant oxidizing species. Multianal. methods verified the selective conversion of DMSO (DMSO) and Ph Me sulfoxide (PMSO) to di-Me sulfone (DMSO2) and Ph Me sulfone (PMSO2), resp., confirming the generation of FeaqIV by the FeaqII-PMS/PDS systems without HCO3-. Significantly, in the presence of environmentally relevant concns. of HCO3-, a carbonate radical anion (CO3•-) becomes the dominant reactive species as confirmed by the ESR (EPR) anal. The new findings suggest that the mechanisms of the persulfate-based Fenton-like reactions in natural environments might differ remarkably from those obtained in ideal conditions. Using sulfonamide antibiotics (sulfamethoxazole (SMX) and sulfadimethoxine (SDM)) as model contaminants, our study further demonstrated the different reactivities of FeaqIV and CO3•- in the FeaqII-PMS/PDS systems. The results shed significant light on advancing the persulfate-based AOPs to oxidize pollutants in natural water.
33科塔普拉斯·维杰（Kottapurath Vijay），A.;马克斯，V.;米兹拉希，A.;温，Y.;马，X.;夏尔马，VK;Meyerstein，D.Fe aq 在碳酸氢盐存在下 II 与过氧单硫酸盐和过氧二硫酸盐的反应：Fe aq IV 和碳酸盐自由基阴离子的形成。环境。Sci. Technol.2023， 57， 6743– 6753， DOI： 10.1021/acs.est.3c00182 - 34Li, N.; Wang, Y.; Cheng, X.; Dai, H.; Yan, B.; Chen, G.; Hou, L. a.; Wang, S. Influences and mechanisms of phosphate ions onto persulfate activation and organic degradation in water treatment: A review. Water Res.IF 12.8SCIEJCI 2.15Q1环境科学与生态学1区Top2022, 222, 118896, DOI: 10.1016/j.watres.2022.118896 Google Scholar Google 学术搜索34https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhvFygs77J&md5=c0cd4327b35f3e769b8af836fe396604Influences and mechanisms of phosphate ions onto persulfate activation and organic degradation in water treatment: A reviewLi, Ning; Wang, Yanshan; Cheng, Xiaoshuang; Dai, Haoxi; Yan, Beibei; Chen, Guanyi; Hou, Li'an; Wang, ShaobinWater Research (2022), 222 (), 118896CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)A review. Currently, various strategies have been applied to activate persulfate (PS) for contaminant removal from water. However, the background phosphate ions in water affect PS activation and org. degrdn., and the mechanism of their influence on the processes is still controversial. In this review, the possible effects of different phosphate forms (HPO2-4, H2PO-4, and PO3-4) on PS activation and contaminant degrdn. were systematically evaluated and summarized. Specifically, HPO2-4 promotes contaminant degrdn. in direct peroxymonosulfate (PMS) oxidn. and thermal/PMS systems, while it exhibits inhibition to thermal/peroxodisulfate (PDS) and UV/PDS systems. Meanwhile, H2PO-4 inhibits most oxidn. processes based on PMS and PDS, except for non-metal dominated and metal assisted PMS systems. Coexisting HPO2-4 and H2PO-4 could present beneficial effects in thermal, Co2+ and non-metal activated and metal assisted PMS systems. Nevertheless, their inhibitory effects were found in direct PMS oxidn., UV/PMS (or PDS) and metal dominated PMS systems. Generally, phosphate ions inhibit PMS/PDS activation through competing adsorption with PMS or PDS on the solid surface, forming a complex with metal ions, as well as occupying active sites on solid catalysts. In addn., phosphate ions can quench radicals for reduced degrdn. of contaminants. However, phosphate ions could weaken the bond dissocn. energy via combining with PMS and contaminants or form a complex with Co2+, thus displaying a facilitative effect. This review further discusses major challenges and opportunities of PS activation with co-existing phosphates and will provide guidance for better PS utilization in real water treatment practice.
34李，N.;王勇;程X.;戴，H.;闫，B.;陈，G.;侯，洛杉矶;磷酸根离子对水处理中过硫酸盐活化和有机降解的影响及其机制研究进展.水资源研究 2022， 222， 118896， DOI： 10.1016/j.watres.2022.118896 - 35Chen, Z.; Wan, Q.; Wen, G.; Luo, X.; Xu, X.; Wang, J.; Li, K.; Huang, T.; Ma, J. Effect of borate buffer on organics degradation with unactivated peroxymonosulfate: Influencing factors and mechanisms. Sep. Purif. Technol.IF 8.6SCIEJCI 1.37Q1工程技术1区Top2021, 256, 117841, DOI: 10.1016/j.seppur.2020.117841 Google Scholar Google 学术搜索35https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitVymu7zN&md5=d11885b2724e4be03878dd9918b88387Effect of borate buffer on organics degradation with unactivated peroxymonosulfate: Influencing factors and mechanismsChen, Zhuhao; Wan, Qiqi; Wen, Gang; Luo, Xinyu; Xu, Xiangqian; Wang, Jingyi; Li, Kai; Huang, Tinglin; Ma, JunSeparation and Purification Technology (2021), 256 (), 117841CODEN: SPUTFP; ISSN:1383-5866. (Elsevier B.V.)Considering that borate buffer is frequently used to maintain the pH in the peroxymonosulfate (PMS)-based advanced oxidn. process and several oxygenated anions (OH-, PO3-4, and CO2-3) can stimulate PMS, the efficient degrdn. of org. pollutants through a PMS/borate system was systematically reported in this work. The presence of borate significantly enhanced the degrdn. of acid orange 7 (AO7) by PMS at all PMS concns., but not by persulfate or hydrogen peroxide. Addnl., concns. of borate from 0.04 to 0.6 M accelerated the degrdn. of AO7 by PMS, while the corresponding kobs values increased and then decreased, reaching a max. of 0.0284 min-1 at 0.1 M borate. The decline at higher borate concns. resulted from the generation of unreactive intermediate peroxoboric acid (HOOB(OH)2) between HSO-5 and H3BO3, which consumed a portion of PMS. The removal of AO7 was stimulated by the presence of borate at lower pH = 7.0-9.0 but was suppressed at a higher of pH 9.5 and 10.0. Based on scavenging expts. and ESR tests, it can be inferred that 1O2 together with SO·-4 and ·OH were responsible for AO7 removal in the PMS/borate system. TOC removal was also enhanced by PMS/borate system compared to PMS alone. PMS/borate system was also effective in the degrdn. of other org. contaminants and preferentially oxidized the electron-rich moieties. Consequently, more attention should be paid to the use of borate buffer in the studies of PMS-based advanced oxidn. processes, and this work can provide a ref. for future research.
35陈志强;万Q.;温，G.;罗X.;徐旭;王军;李杭;黄，T.;马，J.硼酸盐缓冲液对未活化过氧单硫酸盐有机物降解的影响：影响因素和机制。9月普里夫。Technol.2021， 256， 117841， DOI： 10.1016/j.seppur.2020.117841 - 36Li, B.; Cheng, X.; Zou, R.; Yong, X.; Pang, C.; Su, Y.; Zhang, Y. Simple modulation of Fe-based single atoms/clusters catalyst with acidic microenvironment for ultrafast Fenton-like reaction. Appl. Catal., BIF 22.1SCIEJCI 3.14Q1化学1区Top2022, 304, 121009, DOI: 10.1016/j.apcatb.2021.121009 Google Scholar Google 学术搜索36https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXivVagurfM&md5=88f6ccb41c41ceaa14611b72a4b0218eSimple modulation of Fe-based single atoms/clusters catalyst with acidic microenvironment for ultrafast Fenton-like reactionLi, Biao; Cheng, Xiaolong; Zou, Rusen; Yong, Xiaoyu; Pang, Chengfang; Su, Yanyan; Zhang, YifengApplied Catalysis, B: Environmental (2022), 304 (), 121009CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)Single atom catalysts (SACs) are emerging as efficient peroxide activators to eliminate water contaminants, yet the correlation between structure and catalytic activity remains elusive. Here we moderated the Fe sites on the carbon nitride and obtained a combination of single atoms and clusters sites on FeCN5 with the recorded methylene blue oxidn. rate of 59.43 mg/L min-1 via direct ultrafast H2O2 activation. The excellent performance was mainly ascribed to the high active sites exposure, self-creating acidic microenvironment, and assistance of leaching Fe. Nevertheless, excessive exposure of the catalyst at high pH may destroy the surface environment and inhibit H2O2 activation. To solve this issue, we developed a flow-through filter that reached nearly 100% pollutant degrdn. and H2O2 utilization and stability over 320 h when treating actual wastewater treatment. These findings provide profound insights into catalyst manipulation at at. scales and the development of viable catalytic systems toward real-world application.
36李，B.;程X.;邹，R.;杨，X.;庞，C.;苏，Y.;Fe基单原子/团簇催化剂在酸性微环境中的简单调控超快Fenton类反应.应用催化， B2022， 304， 121009， DOI： 10.1016/j.apcatb.2021.121009 - 37Gao, Y.; Zhou, Y.; Pang, S.-Y.; Jiang, J.; Yang, Z.; Shen, Y.; Wang, Z.; Wang, P.-X.; Wang, L.-H. New insights into the combination of permanganate and bisulfite as a novel advanced oxidation process: Importance of high valent manganese-oxo species and sulfate radical. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2019, 53, 3689– 3696, DOI: 10.1021/acs.est.8b05306 Google Scholar Google 学术搜索37https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXltVCgurw%253D&md5=d098404724e0a49bde50a57501e05dc0New Insights into the Combination of Permanganate and Bisulfite as a Novel Advanced Oxidation Process: Importance of High Valent Manganese-Oxo Species and Sulfate RadicalGao, Yuan; Zhou, Yang; Pang, Su-Yan; Jiang, Jin; Yang, Zhifeng; Shen, Yongming; Wang, Zhen; Wang, Pan-Xin; Wang, Li-HongEnvironmental Science & Technology (2019), 53 (7), 3689-3696CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Recently, it has been reported that the combination of permanganate (Mn(VII)) and bisulfite can lead to a rapid degrdn. of org. contaminants, where sol. Mn(III) probably is responsible. We demonstrated the involvement of high-valent Mn-oxo species (possibly Mn(V)) as well as sulfate radical in the Mn(VII)/bisulfite system, by using Me Ph sulfoxide (PMSO) as a chem. probe. The combination of Mn(VII) and bisulfite resulted in appreciable degrdn. of PMSO under various conditions, while negligible PMSO was degraded by Mn dioxide (MnO2) in the presence of bisulfite under similar conditions. Mn(III) intermediate formed in situ in both Mn(VII)/bisulfite and MnO2/bisulfite systems as proposed in literature exhibited sluggish reactivity toward PMSO. In parallel, the formation of Me Ph sulfone (PMSO2) product in the Mn(VII)/bisulfite system was obsd., suggesting the role of high-valent Mn-oxo species as an O-atom donor in conversion of PMSO to PMSO2. Also, the yield of PMSO2 (i.e., mole of PMSO2 produced per mol. of PMSO degraded) was quantified to be 20-100%, strongly depending on the [Mn(VII)]/[bisulfite] ratio as well as soln. pH. The competitive contribution of sulfate radical, which oxidized PMSO to hydroxylated and/or polymeric products but not to PMSO2, accounted for the yield of PMSO2 <100%. This work advances the fundamental understanding of a novel class of oxidn. technol. based on the combination of Mn(VII) and bisulfite for environmental decontamination.
37高Y.;周，Y.;彭淑娟;江 J.;杨振;沈永;王志强;王，P.-X.;高锰酸盐和亚硫酸氢盐结合作为新型高级氧化过程的新见解：高价锰氧基和硫酸盐自由基的重要性。环境。Sci. Technol.2019， 53， 3689– 3696， DOI： 10.1021/acs.est.8b05306 - 38Pan, X.-Q.; Zhang, X.-Y.; Huang, G.-X.; Mei, S.-C.; Huang, J.-W.; Chen, J.-J.; Liu, W.-J.; Yu, H.-Q. Promoting electrocatalytic hydrogenation of 5-hydroxymethylfurfural using buffer electrolytes as proton-donating motifs: Theoretical predictions and experimental validations. Appl. Catal., BIF 22.1SCIEJCI 3.14Q1化学1区Top2023, 323, 122191, DOI: 10.1016/j.apcatb.2022.122191 Google Scholar Google 学术搜索38https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XivFSrsLjM&md5=8658365dbba6bc2d40cc1a12a97edeb9Promoting electrocatalytic hydrogenation of 5-hydroxymethylfurfural using buffer electrolytes as proton-donating motifs: Theoretical predictions and experimental validationsPan, Xiao-Qiang; Zhang, Xin-Yu; Huang, Gui-Xiang; Mei, Shu-Chuan; Huang, Jia-Wei; Chen, Jie-Jie; Liu, Wu-Jun; Yu, Han-QingApplied Catalysis, B: Environmental (2023), 323 (), 122191CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)Electrocatalytic hydrogenation (ECH) represents a promising alternative to conventional hydrogenation techniques with high-pressure H2 as a reductant. The proton-donating motif is an important factor governing the reaction efficiency but is usually overlooked in the ECH process. Herein, on the basis of d. functional theory (DFT) predictions and exptl. validations, we demonstrate that proton-buffer salts such as phosphate, carbonate and borate can greatly promote ECH efficiency. The DFT results predict that the buffer species can outperform water in donating protons for *C=O hydrogenation into *C-OH via the Langmuir-Hinshelwood or proton-coupled electron transfer (PCET) mechanism, thus promoting the hydrogenation of carbonyl compds. The exptl. results demonstrate that with the buffer-promoting effects, 5-hydroxymethylfurfural (HMF) can be effectively converted at an efficiency of 96% into the value-added 2,5-dihydroxymethylfuran (DHMF) with a yield of 80% over cobalt oxide (Co3O4) nanoarray catalysts under near-neutral buffer electrolyte. In situ Raman anal. and kinetic isotope exptl. results reveal that the real mechanism is a combined Langmuir-Hinshelwood and PCET process. Such a buffer-promoting strategy also exhibits wide applicability in ECH of various other carbonyl compds. with different electrode catalysts. This work may provide a deep understanding of the ECH process and open up new opportunities to design effective systems for the conversion of HMF into value-added products.
38潘，X.-Q.;张旭彦;黄国旭;梅，S.-C.;黄建伟;陈建军;刘伟杰;使用缓冲电解质作为质子供体基序促进5-羟甲基糠醛的电催化氢化：理论预测和实验验证。应用催化， B2023， 323， 122191， DOI： 10.1016/j.apcatb.2022.122191 - 39Litvinov, A.; Feintuch, A.; Un, S.; Goldfarb, D. Triple resonance EPR spectroscopy determines the Mn2+ coordination to ATP. J. Magn. Reson.IF 2.2SCIEJCI 0.74Q3化学3区2018, 294, 143– 152, DOI: 10.1016/j.jmr.2018.07.007 Google Scholar Google 学术搜索39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtl2gtrfP&md5=32c36576b691caded06801915eebadccTriple resonance EPR spectroscopy determines the Mn2+ coordination to ATPLitvinov, Aleksei; Feintuch, Akiva; Un, Sun; Goldfarb, DaniellaJournal of Magnetic Resonance (2018), 294 (), 143-152CODEN: JMARF3; ISSN:1090-7807. (Elsevier B.V.)Mn2+ often serves as a paramagnetic substitute to Mg2+, providing means for exploring the close environment of Mg2+ in many biol. systems where it serves as an essential co-factor. This applies to proteins with ATPase activity, where the ATP hydrolysis requires the binding of Mg2+-ATP to the ATPase active site. In this context, it is important to distinguish between the Mn2+ coordination mode with free ATP in soln. as compared to the protein bound case. In this work, we explore the Mn2+ complexes with ATP, the non-hydrolysable ATP analog, AMPPNP, and ADP free in soln. Using W-band 31P electron-nuclear double resonance (ENDOR) we obtained information about the coordination to the phosphates, whereas from electron-electron double resonance (ELDOR) - detected NMR (EDNMR) we detd. the coordination to an adenosine nitrogen. The coordination to these ligands has been reported earlier, but whether the nitrogen and phosphate coordination is within the same nucleotide mols. or different ones is still under debate. By applying the correlation technique, THYCOS (triple hyperfine correlation spectroscopy), and measuring 15N-31P correlations we establish that in Mn-ATP in soln. both phosphates and a nitrogen are coordinated to the Mn2+ ion. We also carried out DFT calcns. to substantiate this finding. In addn., we expanded the understanding of the THYCOS expt. by comparing it to 2D-EDNMR for 55Mn-31P correlation expts. and through simulations of THYCOS and 2D-EDNMR spectra with 15N-31P correlations.
39利特维诺夫，A.;Feintuch，A.;联合国，S.;Goldfarb， D.三重共振EPR波谱法确定了Mn 2+ 与ATP的配位。J.马格。Reson.2018， 294， 143– 152， DOI： 10.1016/j.jmr.2018.07.007 - 40Gao, H.-Y.; Huang, C.-H.; Mao, L.; Shao, B.; Shao, J.; Yan, Z.-Y.; Tang, M.; Zhu, B.-Z. First direct and unequivocal electron spin resonance spin-trapping evidence for pH-dependent production of hydroxyl radicals from sulfate radicals. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2020, 54, 14046– 14056, DOI: 10.1021/acs.est.0c04410 Google Scholar Google 学术搜索40https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitVykurnE&md5=138dfc674522d3908c6fa33d5a6e8e70First Direct and Unequivocal Electron Spin Resonance Spin-Trapping Evidence for pH-Dependent Production of Hydroxyl Radicals from Sulfate RadicalsGao, Hui-Ying; Huang, Chun-Hua; Mao, Li; Shao, Bo; Shao, Jie; Yan, Zhu-Ying; Tang, Miao; Zhu, Ben-ZhanEnvironmental Science & Technology (2020), 54 (21), 14046-14056CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Recently, the sulfate radical (SO4·-) has been found to exhibit broad application prospects in various research fields such as chem., biomedical, and environmental sciences. It has been suggested that SO4·- could be transformed into a more reactive hydroxyl radical (·OH); however, no direct and unequivocal exptl. evidence has been reported yet. In this study, using an ESR (ESR) secondary radical spin-trapping method coupled with the classic spin-trapping agent 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and the typical ·OH-scavenging agent DMSO (DMSO), we found that ·OH can be produced from three SO4·--generating systems from weakly acidic (pH = 5.5) to alk. conditions (optimal at pH = 13.0), while SO4·- is the predominant radical species at pH < 5.5. A comparative study with three typical ·OH-generating systems strongly supports the above conclusion. This is the first direct and unequivocal ESR spin-trapping evidence for ·OH formation from SO4·- over a wide pH range, which is of great significance to understand and study the mechanism of many SO4·--related reactions and processes. This study also provides an effective and direct method for unequivocally distinguishing ·OH from SO4·-.
40高晟;黄振华;毛，L.;邵，B.;邵杰;闫志英;唐，M.;Zhu， B.-Z.第一个直接和明确的电子自旋共振自旋捕获证据，用于从硫酸盐自由基依赖性地产生羟基自由基的pH依赖性证据。环境。Sci. Technol.2020， 54， 14046– 14056， DOI： 10.1021/acs.est.0c04410 - 41Ren, W.; Cheng, C.; Shao, P.; Luo, X.; Zhang, H.; Wang, S.; Duan, X. Origins of electron-transfer regime in persulfate-based nonradical oxidation processes. Environ. Sci. Technol.IF 11.4SCIEJCI 1.44Q1环境科学与生态学1区Top2022, 56, 78– 97, DOI: 10.1021/acs.est.1c05374 Google Scholar Google 学术搜索41https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXislyhsbnJ&md5=a1723888c375d858078b8d7f1f1a7106Origins of Electron-Transfer Regime in Persulfate-Based Nonradical Oxidation ProcessesRen, Wei; Cheng, Cheng; Shao, Penghui; Luo, Xubiao; Zhang, Hui; Wang, Shaobin; Duan, XiaoguangEnvironmental Science & Technology (2022), 56 (1), 78-97CODEN: ESTHAG; ISSN:1520-5851. (American Chemical Society)A review. Persulfate-based nonradical oxidn. processes (PS-NOPs) are appealing in wastewater purifn. due to their high efficiency and selectivity for removing trace org. contaminants in complicated water matrixes. In this review, we showcased the recent progresses of state-of-the-art strategies in the nonradical electron-transfer regimes in PS-NOPs, including design of metal and metal-free heterogeneous catalysts, in situ/operando characterization/anal. techniques, and insights into the origins of electron-transfer mechanisms. In a typical electron-transfer process (ETP), persulfate is activated by a catalyst to form surface activated complexes, which directly or indirectly interact with target pollutants to finalize the oxidn. We discussed different anal. techniques on the fundamentals and tactics for accurate anal. of ETP. Moreover, we demonstrated the challenges and proposed future research strategies for ETP-based systems, such as computation-enabled mol.-level investigations, rational design of catalysts, and real-scenario applications in the complicated water environment. Overall, this review dedicates to sharpening the understanding of ETP in PS-NOPs and presenting promising applications in remediation technol. and green chem.
41任，W.;程，C.;邵，P.;罗X.;张，H.;王，S.;Duan， X.基于过硫酸盐的非自由基氧化过程中电子转移机制的起源。环境。Sci. Technol.2022， 56， 78– 97， DOI： 10.1021/acs.est.1c05374 - 42Zhang, Y.-J.; Chen, J.-J.; Huang, G.-X.; Li, W.-W.; Yu, H.-Q.; Elimelech, M. Distinguishing homogeneous advanced oxidation processes in bulk water from heterogeneous surface reactions in organic oxidation. Proc. Natl. Acad. Sci. U.S.A.IF 11.1SCIEJCI 2.52Q1综合性期刊1区Top2023, 120, e2302407120, DOI: 10.1073/pnas.2302407120 Google Scholar Google 学术搜索There is no corresponding record for this reference.
42张永俊;陈建军;黄国旭;李，W.-W.;俞汉清;Elimelech， M.区分散装水中的均质高级氧化过程与有机氧化中的非均相表面反应。美国国家科学院院刊 2023， 120， e2302407120， DOI： 10.1073/pnas.2302407120
Cited By 施引文献
This article has not yet been cited by other publications.
本文尚未被其他出版物引用。