Preparation of an In2S3/TiO2 Heterostructure for Enhanced Activity in Carbon Dioxide Photocatalytic Reduction

Constructing a heterojunction structure is considered to be a promising strategy for the photocatalytic reduction of carbon dioxide. Herein, In2S3/TiO2 composite materials were successfully prepared by a hydrothermal method and were used for the construction of a typical type II heterojunction. Through optimizing the In2S3/TiO2 ratio, a high separation efficiency of the photogenerated electron‐hole pairs has been achieved. Therefore, 5 % In2S3/TiO2 showed a CH4 production rate of 16.21 μmol g−1 h−1 without using additional sacrificial agent, and the catalytic activity far exceeds that of pure TiO2 nanosheets. The high catalytic activity of the hybrid catalyst can be ascribed to the high specific surface area, enhanced visible light harvesting ability and improved electron transport capability. In addition, based on the XPS valence band spectrum, UV/Vis DRS and photoelectrochemical characteristics, a possible mechanism for the reduction of CO2 by 5 % In2S3/TiO2 photocatalyst is proposed. More than the sum of its parts: TiO2 nanosheets and In2S3 nanosheets are integrated by a solvothermal method to construct a type II heterojunction. The composite material demonstrates excellent photocatalytic carbon dioxide reduction performance facilitated by enhanced light absorption and enhanced charge transport capabilities.