Electro-catalytic activity of CeOx modified graphite felt for carbamazepine degradation via E-peroxone process

E-peroxone (EP) was one of the most attractive AOPs for removing refractory organic compounds from water, but the high energy consumption for in situ generating H2O2 and its low reaction efficiency for activating O-3 under acidic conditions made the obstacles for its practical application. In this study, cerium oxide was loaded on the surface of graphite felt (GF) by the hydrothermal method to construct the efficient electrode (CeOx/GF) for mineralizing carbamazepine (CBZ) via EP process. CeOx/GF was an efficient cathode, which led to 69.4% TOC removal in CeOx/GF-EP process with current intensity of 10 mA in 60 min. Moreover, CeOx/GF had the flexible application in the pH range from 5.0 to 9.0, TOC removal had no obvious decline with decrease of pH. Comparative characterizations showed that CeOx could enhance surface hydrophilicity and reduce the charge-transfer resistance of GF. About 5.4 mg/L H2O2 generated in CeOx/GF-EP process, which was 2.1 times as that in GF-EP process. The greater ozone utility was also found in CeOx/GF-EP process. More O-3 was activated into hydroxyl radicals, which accounted for the mineralization of CBZ. An interfacial electron transfer process was revealed, which involved the function of oxygen vacancies and Ce3+/Ce4+ redox cycle. CeOx/GF had the good recycling property in fifth times' use. (C) Higher Education Press 2021

Automated summary

CeOx/GF was successfully constructed as an efficient electrode for mineralizing CBZ via EP process, showing high TOC removal efficiency, wide pH range adaptability, increased H2O2 generation, enhanced ozone utility, and promotion of CBZ mineralization.