Enhanced electro-Fenton degradation of sulfamethazine using Co-based selenite modified graphite cathode via in-situ generation of •OH

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 463; p. 142419
• Main Authors: Sun, Wenxin, Zhou, Lingli, Liu, Guoshuai, Zheng, Yi, Zou, Hua, Song, Junling
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2023
• Subjects: Antibiotics treatment; Co-based selenite; Electro-Fenton; Hydrogen peroxide electro-synthesis; Proton transfer; CoSeO@GP; EF; SMZ; Electro-Fenton; AOP; Co-based selenite; PTFE; Proton transfer; Hydrogen peroxide electro-synthesis; GP; ECSA; ORR; CoSeO; ROSs; Antibiotics treatment
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.142419

[Display omitted] •Novel Co12(OH)2(SeO3)8(OH)6 zeolite-type electrocatalyst was synthesized.•CoSeO@GP cathode presented enhanced electrocatalytic activity for H2O2 production.•CoSeO@GP cathode exhibited excellent SMZ degradation efficiency and stability.•Degradation pathways and the toxicity of SMZ during degradation were studied. Electro-Fenton (EF) reaction has been regarded as a promising technology for practical wastewater treatments. However, the generation of H2O2 and •OH was limited by low O2 utilization and protonation efficiency in the conventional EF system. This research synthesized a novel electrocatalyst, Co12(OH)2(SeO3)8(OH)6 (CoSeO) to achieve efficient wastewater treatment via in-situ H2O2 generation in the EF system. The modified graphite plate-based cathode (CoSeO@GP) was fabricated by using a facile hydrothermal method combined with a simple coating. The CoSeO@GP cathode that had both hydrophilic and aerophilic properties achieved efficient H2O2 production (26.15 mgL-1h−1) at low air flow rate. Moreover, the average protonation rate was significantly improved to 0.00803 molH-1min−1 with this cathode. The presence of Co2+/Co3+ could significantly promote the in situ H2O2 decomposition, and boost the production of •OH. Sulfamethazine (SMZ) was completely degraded in 90 min with the kinetic constant of 0.05959 min−1 by using the CoSeO@GP cathode. In addition, this cathode maintained high stability and applicability after a 10-cycle continuous operation. This study provided a proof-of-concept design strategy for developing novel EF cathodes for the treatment of recalcitrant pollutants.