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

Abstract Constructing a heterojunction structure is considered to be a promising strategy for the photocatalytic reduction of carbon dioxide. Herein, In 2 S 3 /TiO 2 composite materials were successfully prepared by a hydrothermal method and were used for the construction of a typical type II heterojunction. Through optimizing the In 2 S 3 /TiO 2 ratio, a high separation efficiency of the photogenerated electron‐hole pairs has been achieved. Therefore, 5 % In 2 S 3 /TiO 2 showed a CH 4 production rate of 16.21 μmol g −1 h −1 without using additional sacrificial agent, and the catalytic activity far exceeds that of pure TiO 2 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 CO 2 by 5 % In 2 S 3 /TiO 2 photocatalyst is proposed.