Fast charge transfer kinetics in Sv-ZnIn2S4/Sb2S3 S-scheme heterojunction photocatalyst for enhanced photocatalytic hydrogen evolution

Constructing a S-scheme heterojunction with tight interface contact and fast charge transfer is beneficial to improving the photocatalytic hydrogen evolution performance. Herein, a unique one-dimensional (1D)/two-dimensional (2D) S-scheme heterojunction containing 1D Sb2S3 nanorods and 2D ZnIn2S4 with affluent sulfur vacancies (denoted as Sv-ZnIn2S4@Sb2S3) was designed. The introduced sulfur vacancy can promote the effective adsorption of H+ for the following interfacial hydrogen-evolution reaction. Furthermore, the larger contact area and stronger electron interaction between Sb2S3 and ZnIn2S4 effectively inhibits the recombination of photo-generated electron–hole pairs and abridges the migration distance of charges. As a result, the optimal Sv-ZnIn2S4@Sb2S3 sample achieves H2 evolution activity of 2741.3 mol·h−1·g−1, which is 8.6 times that of pristine ZnIn2S4 and 3.0 times that of the Sv-ZnIn2S4 samples. Based on the experimental result, the photo-reactivity S-scheme mechanism of hydrogen evolution from water splitting with Sv-ZnIn2S4@Sb2S3 is proposed. This work provides an effective method for developing S-scheme heterojunction composites of transition metal sulfide with high hydrogen evolution performance.