Construct the sulfur-vacancy rich In2S3/Ni Schottky junction to largely boost the visible light-driven photocatalytic synthesis of hydrogen peroxide

The photocatalytic production of H 2 O 2 from H 2 O and O 2 via solar light-driven is a low-cost, safe, and environmentally friendly route for H 2 O 2 production, but the high carrier recombination rate and insufficient active sites in the photocatalytic process greatly limit the efficiency of H 2 O 2 generation. Here, we combined both vacancy modification and heterojunction engineering strategies to modify In 2 S 3 , successfully constructing In 2 S 3 /Ni Schottky junctions (SvIS/Ni) with rich S vacancies via a two-step calcination-photo-deposition method. The introduction of rich S vacancies and the formation of Ni Schottky both enhance the absorption of visible light by In 2 S 3 and substantially improve its carrier separation efficiency. Notably, we also found that SvIS/Ni is capable of realizing multi-channel reaction pathways for oxygen reduction and water oxidation to promote the H 2 O 2 generation. Benefiting from the above advantages, the H 2 O 2 yield of SvIS/Ni in the pure water system under visible light irradiation could reach 1146.6 µmol·g −1 h −1 , which is 13.4 times that of pure In 2 S 3 , and the apparent quantum yield (AQY) at 400 nm can reach 3.58 %. This study provides a novel idea for designing highly efficient photocatalysts by combining defect engineering and heterojunction modification strategies.