Rationally construct of CoSx/MoS2/g-C3N4 double heterojunction with promoting the separation of carriers for enhanced photocatalysis

g-C3N4 (CN) has attracted extensive attention in photocatalysis field, but its weak visible light absorption and rapid charge recombination limit its application. In this, MoS2 and CoSx (ZIF67 derivatives) as cocatalyst grew on the surface of semiconductor CN in situ to construct CoSx/MoS2/CN double heterojunction. Then the activities of photocatalytic hydrogen evolution and degradation MB were researched. The hydrogen production rate of 5%CoSx/MoS2/CN-2 photocatalyst is 9800 mmol h-1 g-1 and is about 6.5 times as great as CN, 46 times than MoS2 and 98 times than CoSx, respectively. Under natural sunlight and simulated sunlight, the degradation efficiency of MB is 99.95% and 99.50% after 4 h, respectively. Catalyst characterizations have pointed out that CoSx/MoS2/CN catalyst has abundant active sites and larger specific surface area, which increase absorption of water and oxygen. At the same time, internal electric field and S vacancy enhance electrons transfer rate, which effectively inhibit the recombination of e --h+. This work provides a new idea into the creation of steady, high-efficiency and continuable photocatalytic cata-lyst for visible light. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, a CoSx/MoS2/CN double heterojunction was constructed by growing MoS2 and CoSx (ZIF67 derivatives) as cocatalyst on the surface of g-C3N4 semiconductor in situ. The activities of photocatalytic hydrogen evolution and degradation of MB were investigated. The hydrogen production rate of 5%CoSx/MoS2/CN-2 photocatalyst is 9800 mmol h-1 g-1, which is about 6.5 times higher than CN, 46 times higher than MoS2 and 98 times higher than CoSx, respectively. Under natural sunlight and simulated sunlight, the degradation efficiency of MB is 99.95% and 99.50% after 4 hours, respectively. This study provides a new idea for the development of steady, high-efficiency, and sustainable photocatalytic catalysts for visible light.