Regulating the Electronic Structure of Cu Single-Atom Catalysts toward Enhanced Electro-Fenton Degradation of Organic Contaminants via <sup>1</sup>O<sub>2</sub> and <sup>•</sup>OH
Genwang Zhu, Xinfei Fan, Yueling Yu, Yanming Liu, Xie Quan
Abstract
Heterogeneous electro-Fenton degradation with 1 O 2 and • OH generated from O 2 reduction is cost-effective for the removal of refractory organic pollutants from wastewater. As 1 O 2 is more tolerant to background constituents such as salt ions and a high pH value than • OH, tuning the production of 1 O 2 and • OH is important for efficient electro-Fenton degradation. However, it remains a great challenge to selectively produce 1 O 2 and improve the species yield. Herein, the electronic structure of atomically dispersed Cu–N 4 sites was regulated by doping electron-deficient B into porous hollow carbon microspheres (CuBN-HCMs), which improved *O 2 adsorption and significantly enhanced 1 O 2 selectivity in electro-Fenton degradation. Its 1 O 2 yield was 2.3 times higher than that of a Cu single-atom catalyst without B doping. Meanwhile, • OH was simultaneously generated as a minor species. The CuBN-HCMs were efficient for the electro-Fenton degradation of phenol, sulfamethoxazole, and bisphenol A with a high mineralization efficiency. Its kinetic constants showed insignificant changes under various anions and a wide pH range of 1–9. More importantly, it was energy-efficient for treating actual coking wastewater with a low energy consumption of 19.0 kWh kg COD –1 . The superior performance of the CuBN-HCMs was contributed from 1 O 2 and • OH and its high 1 O 2 selectivity.