Constructing a 2D/2D interfacial contact in ReS2/TiO2via Ti–S bond for efficient charge transfer in photocatalytic hydrogen production

Abstract

Exploring and adjusting the transport path of photo-generated carriers is vital to promote the charge separation efficiency and charge transfer ability for the photocatalytic hydrogen performance of novel semiconductor composites. Herein, this work focuses on the construction of a homojunction and heterojunction in semiconductors by fabricating ReS₂ nanosheets on a TiO₂ homojunction via Ti–S bond. The optimized built-in electric field of the homojunction immensely inhibits the recombination of photo-generated electrons and holes. The 2D/2D intimate interfacial contact between ReS₂ nanosheets and 2D TiO₂ is achieved by Ti–S bond, which gains high hydrogen evolution efficiency due to the shorter migration carrier distance and more rapid charge transfer. Additionally, theoretical calculations demonstrate that the O vacancy possesses stronger chemical interaction with sulfides in order to form a Ti–S bond. Compared with pure TiO₂ and physical mixtures of ReS₂ and TiO₂, the optimized ReS₂/TiO₂ sample possesses 20 times and 3.6 times higher photocatalytic hydrogen performance, respectively. This work obtains an efficient charge transfer pathway of photocatalysts by preventing the recombination of carriers, which provides some new designs for growing sulfides and investigating the interfacial contact of photocatalysts.