TiO2/In2S3 S-scheme photocatalyst with enhanced H2O2-production activity

Photocatalytic production of hydrogen peroxide (H2O2) is an ideal pathway for obtaining solar fuels. Herein, an S-scheme heterojunction is constructed in hybrid TiO2/In2S3 photocatalyst, which greatly promotes the separation of photogenerated carriers to foster efficient H2O2 evolution. These composite photocatalysts show a high H2O2 yield of 376 mu mol/(L center dot h). The mechanism of charge transfer and separation within the S-scheme heterojunction is well studied by computational methods and experiments. Density functional theory and in-situ irradiated X-ray photoelectron spectroscopy results reveal distinct features of the S-scheme heterojunction in the TiO2/In2S3 hybrids and demonstrate charge transfer mechanisms. The density functional theory calculation and electron paramagnetic resonance results suggest that O-2 reduction to H2O2 follows stepwise one-electron processes. In2S3 shows a much stronger interaction with O-2 than TiO2 as well as a higher reduction ability, serving as the active sites for H2O2 generation. The work provides a novel design of S-scheme photocatalyst with high H2O2 evolution efficiency and mechanistically demonstrates the improved separation of charge carriers.

Automated summary

An S-scheme heterojunction is constructed in a hybrid TiO2/In2S3 photocatalyst, which greatly promotes the separation of photogenerated carriers and enhances the production of H2O2. Computational methods and experiments are used to study the charge transfer and separation mechanisms within the S-scheme heterojunction.