Enhanced photoexcited carrier separation in CdS–SnS2 heteronanostructures: a new 1D–0D visible-light photocatalytic system for the hydrogen evolution reaction
Photocatalytic water splitting to produce hydrogen is a significant reaction for renewable energy storage and needs highly efficient and stable catalysts. Considering the attractive properties such as a suitable bandgap, high specific surface area and appropriate band structure one-dimensional CdS is a promising visible-light photocatalyst; however, its severe recombination rate and photocorrosion impede its widespread application. Fabrication of heterostructures composed of heterojunctions is a very effective approach to design highly stable and active photocatalytic systems. Here, we report for the first time the fabrication of one-dimensional (1D)/zero-dimensional (0D) core–shell heteronanostructures (CSHNSs), where 0D SnS2 quantum dots are grown on the surface of 1D CdS nanorods to realize efficient H2 evolution reaction under sunlight. The proposed CdS–SnS2 CSHNS system significantly improved the electron–hole separation efficiency between CdS and SnS2 components. Meanwhile in the core–shell structure, the deposited SnS2 quantum dots not only act as a shielding layer to restrain CdS photocorrosion but also have a large contact interface which can further improve the electron–hole separation efficiency. As a result, the optimized CdS–SnS2 CSHNS photocatalyst exhibits excellent visible light absorption and shows a superior hydrogen evolution rate of 35.65 mmol g−1 h−1 under the illumination of simulated sunlight with very good stability.