Synergistic Electrocatalytic Hydrogen Evolution and Peroxymonosulfate Activation over CoS/CoTiO3 Nanocomposites for Levofloxacin Degradation

Abstract

Abstract The global energy crisis and escalating water pollution necessitate the development of sustainable technologies that integrate environmental remediation with clean energy production. Therefore, if key technologies for hydrogen production from organic pollutant waste liquids can be developed, it will have significant value for both energy production and environmental governance. In this work, CoS/CoTiO3 composite catalysts were prepared, and the electrocatalytic hydrogen evolution reaction was coupled with advanced persulfate oxidation technology. The degradation performance of levofloxacin (LEV) catalyst in a coupled system was systematically evaluated, and its electrocatalytic hydrogen evolution activity was investigated. The experimental results showed that under the conditions of an initial LEV concentration of 20 mg·L–1, catalyst dosage of 0.5 g·L–1, and PMS dosage of 0.8 mmol·L–1, the degradation rate of LEV by CoS/CoTiO3 coupling system could reach over 97%, significantly better than that of a single CoTiO3 coupling system (50%). In terms of electrocatalytic hydrogen evolution performance, the overpotential of CoS/CoTiO3 composite catalyst decreased by about 300 mV compared to CoTiO3, with a Tafel slope of 251.7 mV·dec–1, while the Tafel slope of CoTiO3 was 329.2 mV·dec–1, indicating a significant enhancement in the hydrogen evolution reaction kinetics of the composite material. The CoS/CoTiO3 composite catalyst constructed in this study achieves efficient degradation of organic pollutants and synergistic coupling of electrocatalytic hydrogen evolution, providing a technological approach for waste liquid resource utilization and clean energy production. It has important application potential in the fields of environmental pollution control and hydrogen energy development.