He Li, Yao Fubing, Zhong Yu, Tan Chang, Chen Shengjie, Pi Zhoujie, Li Xiaoming, Yang Qi
College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
School of Metallurgy and Environment, Central South University, Changsha 410083, China; Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Changsha 410083, PR China.
J Hazard Mater. 2024 May 15;470:134120. doi: 10.1016/j.jhazmat.2024.134120. Epub 2024 Mar 24.
Numerous chlorinated disinfection by-products (DBPs) are produced during the chlorination disinfection of water. Among them, chloroacetic acids (CAAs) are of great concern due to their potential human carcinogenicity. In this study, effective electrocatalytic dechlorination of trichloroacetic acids (TCAA), a typical CAAs, was achieved in the electrochemical system with the three-dimensional (3D) self-supported CoP on cobalt foam modified by carbon nanotubes (CNT/CoP/CF) as the cathode. At a 10 mA cm current density, 74.5% of TCAA (500 μg L) was converted into AA within 100 min. In-situ growth of CoP increased the effective electrochemical surface area of the electrode. Electrodeposited CNT promoted electron transfer from the electrode surface to TCAA. Therefore, the production of surface-adsorbed atomic hydrogen (H*) on CNT/CoP/CF was improved, further resulting in excellent electrochemical dechlorination of TCAA. The dechlorination pathway of TCAA proceeded into acetic acids via direct electronic transfer and H*-mediated reduction on CNT/CoP/CF electrode. Additionally, the electroreduction efficiency of CNT/CoP/CF for TCAA exceeded 81.22% even after 20 cycles. The highly efficient TCAA reduction performance (96.57%) in actual water revealed the potential applicability of CNT/CoP/CF in the complex water matrix. This study demonstrated that the CNT/CoP/CF is a promising non-noble metal cathode to remove chlorinated DBPs in practice.
在水的氯化消毒过程中会产生大量的含氯消毒副产物（DBPs）。其中，氯乙酸（CAAs）因其潜在的人类致癌性而备受关注。在本研究中，以碳纳米管修饰的泡沫钴上的三维（3D）自支撑CoP作为阴极的电化学系统中，实现了典型的CAAs——三氯乙酸（TCAA）的有效电催化脱氯。在10 mA cm的电流密度下，100分钟内500 μg L的TCAA中有74.5%转化为乙酸（AA）。CoP的原位生长增加了电极的有效电化学表面积。电沉积的碳纳米管促进了电子从电极表面向TCAA的转移。因此，CNT/CoP/CF上表面吸附的原子氢（H*）的生成得到改善，进一步导致TCAA具有优异的电化学脱氯性能。TCAA的脱氯途径通过直接电子转移和在CNT/CoP/CF电极上的H*介导还原转化为乙酸。此外，即使经过20次循环，CNT/CoP/CF对TCAA的电还原效率仍超过81.22%。在实际水中高效的TCAA还原性能（96.57%）揭示了CNT/CoP/CF在复杂水基质中的潜在适用性。本研究表明，CNT/CoP/CF是一种在实际中去除含氯DBPs的有前景的非贵金属阴极。
