Boosting oxygen activation by CoP/carbon nitride photocatalyst in low-concentration H2S oxidation

Abstract

Aerobic photocatalytic oxidation is considered as an efficient and green method to remedy low-concentration H₂S pollutants associated with the energy and chemical industries. However, the fabrication of a sulfur-resistant catalyst with good performance is a great challenge because of the poisoning effect of H₂S and the difficulty in oxygen (O₂) activation. Herein, a photocatalytic hybrid material composed of chemically stable cobalt phosphide (CoP) and structural base-enriched carbon nitride (CN) was developed for the efficient oxidation of H₂S, which could achieve 95% H₂S conversion, and its service time could last more than 35 h with over 80% H₂S conversion. Reflecting from the characterizations and theoretical simulations, the enhanced H₂S conversion was on account that CoP could stimulate the electrons shuttling from the photocatalytic system towards the gaseous O₂, facilitating the production of critical superoxide radical via the O₂ reduction process and accelerating the surface H₂S oxidation process. This work provides new insights into the design of a sustainable photocatalytic oxidation system for the treatment of chemically active contaminants through constructing stable interfacial electron transfer channels for prominent O₂ activation.