Utilizing photocorrosion-recrystallization to prepare a highly stable and efficient CdS/WS2 nanocomposite photocatalyst for hydrogen evolution

Efficiency and stability are the two key elements for photocatalyst. The application of CdS, as a classical photocatalyst, has been seriously restricted because of the inherent photocorrosion issue. Based on the rate-theory analysis, in this paper, we propose the photocorrosion and recrystallization of CdS on the surface of WS2 nanosheets under visible light irradiation to resolve the photocorrosion issue. A highly stable and efficient CdS/WS2 photocatalyst has been obtained following this strategy for the first time. The rate of H2 evolution distinctly increases (56.2 times) compared with that in pure CdS nanoparticles, and keeps excellent stability in hydrogen generation for more than 200 h without any decrease, which are superior to any other previously reported CdS based photocatalysts. This new approach has potential application in designing and fabricating more stable and efficient composite chalcogenide photocatalysts.