Honeycomb-like porous carbon loaded with CdS/ZnS heterojunction with enhanced photocatalytic performance towards tetracycline degradation and H2 generation

Abstract

Accelerating the charge separation efficiency is a crucial approach to improve the photocatalytic performance of semiconductors. The design and synthesis of heterojunctions can effectively inhibit the recombination of photogenerated electron-hole pairs and enhance the charge separation efficiency. In this work, an easy-handling calcination route was proposed to prepare CdS/ZnS heterojunction loaded on honeycomb-like porous carbon (CZS@C) using chitosan as a precursor. The unique honeycomb-like porous structure facilitated the separation and migration of photoexcited electrons and holes, improving the utilization of visible light and shortening the distance of electron transport. The photocatalytic performance of CZS@C was evaluated by the degradation of tetracycline (TC) and H2 production from water splitting under visible light. The optimized CZS@C composite can degrade almost 92.40 % of TC under visible light irradiation in 60 min. Such CZS@C composite presented an excellent photocatalytic activity with H2 production rate of 5.49 mmol h−1 g−1, which was 54.9 and 2.28-folds higher than ZnS@C and CdS@C. Furthermore, the possible photocatalytic reaction mechanism and pathway towards TC degradation and simultaneous H2 generation was proposed.