Designing and fabricating a CdS QDs/Bi 2 MoO 6 monolayer S-scheme heterojunction for highly efficient photocatalytic C 2 H 4 degradation under visible light

Achieving efficient photocatalytic degradation of atmospheric volatile organic compounds (VOCs) under sun-light is still a significant challenge for environmental protection. The S-scheme heterojunction with its unique charge migration route, high charge separation rate and strong redox ability, has great potential. However, how to regulate interfacial charge transfer of the S-scheme heterojunction is of significant importance. Here, density functional theory (DFT) calculations were first conducted and predicted that an S-scheme heterojunction could be formed in the CdS quantum dots/Bi MoO monolayer system. Subsequently, this novel heterojunction is constructed by in-situ hydrothermal synthesis of CdS quantum dots on monolayer Bi MoO . Under visible-light, this novel S-scheme system gives a high-efficiency photocatalytic degradation rate (6.04 × 10 min ) towards C H , which is 30.3 times higher than that of pure CdS (1.99 × 10 min ) and 41.7 times higher than pure Bi MoO (1.45 × 10 min ). Strong evidence for the S-scheme charge transfer path is provided by in-situ XPS, PL, TRPL and EPR.