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

Abstract

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.