A novel electrocatalytic filtration system with carbon nanotube supported nanoscale zerovalent copper toward ultrafast oxidation of organic pollutants.
A novel electrocatalytic filtration system with carbon nanotube supported nanoscale zerovalent copper toward ultrafast oxidation of organic pollutants.
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DOI：
10.1016/j.watres.2021.116961
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发表时间：
2021-02
期刊：
影响因子：
12.8
通讯作者：
Wentian Zheng;Yanbiao Liu;Wen Liu;Haodong Ji;Fang Li;Chensi Shen;Xiaofeng Fang;X. Li;
中科院分区：
文献类型：
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作者：
Wentian Zheng;Yanbiao Liu;Wen Liu;Haodong Ji;Fang Li;Chensi Shen;Xiaofeng Fang;X. Li;
在这项研究中，我们设计了一种集成电化学过滤系统，用于催化活化过一硫酸盐 (PMS) 和降解水性微污染物。开发了碳纳米管（CNT）和纳米零价铜（nZVC）复合材料，可同时用作高性能催化剂、电极和过滤介质。我们观察到自由基和非自由基反应途径，它们共同促进了模型污染物的降解。在中性 pH 值下，单次通过 nZVC 单键碳纳米管过滤器 (τ <2 s)，刚果红被完全去除。刚果红降解的快速动力学在较宽的 pH 范围（3.0-7.0）、复杂的基质（例如自来水和湖水）中以及多种持久性有机污染物的降解中保持。 nZVC 单键碳纳米管的优异活性源于外部电场存在下 Cu2+/Cu+ 氧化还原循环的增强。由于对流增强的传质，流通式设计的性能明显优于传统的间歇系统。机理研究表明，CNT的羰基和亲电子氧分别作为电子供体和电子受体，通过电子传输激活PMS生成•OH和1O2。缺电子的Cu原子很容易通过表面羟基与PMS反应生成活性中间体(Cu2+-O-O-SO3−)，然后通过破坏亚稳态中间体的配位键生成1O2。该研究将通过基于催化氧化、电化学和纳滤技术的高效集成系统为有机污染修复提供绿色策略。
In this study, we designed an integrated electrochemical filtration system for catalytic activation of peroxymonosulfate (PMS) and degradation of aqueous microcontaminants. Composites of carbon nanotube (CNT) and nanoscale zero valence copper (nZVC) were developed to serve as high-performance catalysts, electrode and filtration media simultaneously. We observed both radical and nonradical reaction pathways, which collectively contributed to the degradation of model pollutants. Congo red was completely removedviaa single-pass through the nZVCsingle bondCNT filter (τ <2 s) at neutral pH. The rapid kinetics of Congo red degradation were maintained across a wide pH range (from 3.0–7.0), in complicated matrixes (e.g., tap water and lake water), and for the degradation of a wide array of persistent organic contaminants. The superior activity of nZVCsingle bondCNT stems from the boosted redox cycles of Cu2+/Cu+in the presence of an external electric field. The flow-through design remarkably outperformed the conventional batch system due to the convection-enhanced mass transport. Mechanism studies suggested that the carbonyl group and electrophilic oxygen of CNT served as electron donor and electron acceptor, respectively, to activate PMS to generate •OH and1O2viaone-electron transport. The electron-deficient Cu atoms are prone to react with PMSviasurface hydroxyl group to produce reactive intermediates (Cu2+-O-O-SO3−), and then1O2will be generated by breaking the coordination bond of the metastable intermediate. The study will provide a green strategy for the remediation of organic pollution by a highly efficient and integrated system based on catalytic oxidation, electrochemistry, and nano-filtration techniques.