Enhanced photoexcited carrier separation in CdS-SnS2 heteronanostructures: a new 1D-0D visible-light photocatalytic system for the hydrogen evolution reaction

摘要

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 H-2 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.