Synergism of electronic structure regulation and interface engineering for boosting hydrogen evolution reaction on S-Scheme FeS2/S-ZnSnO3 heterostructure

The customization of the photocatalyst's composition and structure to achieve enhanced hydrogen (H2) evolution performance is still a major challenge. Herein, FeS2/S-ZnSnO3 (FeS2@S-ZSO) heterostructure was constructed for efficient photocatalytic hydrogen evolution reaction (HER) activity. The band structure of ZnSnO3 was regulated by sulfur doping (S-ZSO), followed by coupling with FeS2 nanoparticles to form a composite enabling improved optical absorption range and efficient spatial separation/transfer of photogenerated carriers. The HER performance of the optimal heterostructure (8.7%FeS2@S15%-ZSO) achieved 2225 μmol g-1 h-1, which was 14.4, 5 and 12.6 times greater than ZSO, S15%-ZSO and FeS2, respectively. DFT-based calculations further validated that S doping regulates the electronic structure of S-ZSO, while the coupling of FeS2 constructs a S-Scheme heterostructure, which accelerates the carrier separation and transport dynamics resulting in the improvement of the HER performance. This study presents a novel approach to improve the photocatalytic HER performance of wide bandgap semiconductors through electronic structural regulation and interface engineering approaches.