Directional spatial charge separation in well-designed S-scheme In2S3–ZnIn2S4/Au heterojunction toward highly efficient photocatalytic hydrogen evolution

Abstract

Constructing efficient and stable photocatalysts are quite crucial for solar-to-hydrogen energy conversion, which remains a great challenge. Nowadays, many photocatalysts still suffer from low solar energy conversion efficiency due to the rapid recombination of photoirradiated carriers mainly caused by their random flow. Regulating charge separation and transport is essential to improve the catalytic activity of photocatalysts toward highly efficient photocatalytic hydrogen production. Herein, a S-scheme In2S3–ZnIn2S4/Au heterojunction with coherent interfaces were constructed. Particularly, as a reduction cocatalyst, the plasmonic metallic Au nanoparticles were loading on the outer surface of S-scheme In2S3–ZnIn2S4 heterojunction. The coordination of S-scheme heterojunction and reductive cocatalyst can produce a directional spatial charge separation and transfer in In2S3–ZnIn2S4/Au heterojunction, leading to a highly efficient photocatalytic hydrogen production. As expected, the well-designed S-scheme In2S3–ZnIn2S4/Au heterojunction presents a remarkable H2 production rate of 12,369 μmol h−1 g−1. This charge transfer modulation mechanism may be applied to design other remarkable photocatalytic materials for efficient solar energy conversion.