Electrocatalytic dechlorination of Florfenicol using crystalline Co3S4/Ni3S4 nanowires arrayed on nickel foam via cathodic reduction

Abstract

Chlorinated antibiotics, particularly Florfenicol (FF), pose a serious global threat to humans and animals by contaminating freshwater and causing water pollution. Electrocatalytic dechlorination (ECH) is effective for removing chlorinated organic compounds during wastewater treatment and water remediation, however, there are limited reports on high-performance, cost-effective, and environmentally friendly cathode materials. In this study, a catalyst was prepared using a two-step hydrothermal process, and a vertically grown 2D Co3S4/Ni3S4 heterostructure was constructed on a nickel foam electrode. Owing to its inherently high electron transfer performance and H* adsorption properties, extensive dechlorination of FF could be achieved via cathodic reduction. The electrode formed using a 100 mM Na2S concentration during the hydrothermal reaction exhibited an optimal crystal composition and morphology, resulting in a substantial electrocatalytic dechlorination effect exhibiting nearly 100 % FF removal after 120 min at −1 V vs Ag/AgCl. The experimental results indicated that the dechlorination of FF is primarily achieved via direct electron transfer, with the degradation rate decreasing by only 5 % after the addition of 400 mM tert-butanol, confirming that H* played a supporting role. Therefore, this study proposes a cost-effective and sustainable electrochemical approach for reducing chlorinated antibiotics using a highly efficient non-noble metal electrode material. It can be successfully utilized as an effective, eco-friendly electrochemical strategy for the removal of similar antibiotics.