Construction of IO-B-TiO2/In2O3 S-scheme heterojunction with photothermal effects and its highly efficient photocatalytic reduction of CO2 under full-spectrum light

The conversion of greenhouse gases such as carbon dioxide (CO2) into fuel and high-value chemical materials using solar energy is considered as a viable solution to the environmental pollution and the alleviation of the energy crisis. Herein, a black titanium dioxide/indium oxide S-scheme heterojunction (IO-B-TiO2/In2O3) with a three-dimensional porous inverse opal structure was prepared. In the photocatalytic reduction of CO2, IO-B-TiO2/In2O3 exhibited an excellent CO production rate (251.25 μmol·g−1·h−1), being 8.62 and 1.55 times of pure IO-TiO2 and IO-B-TiO2/In2O3 under non-photothermal conditions, respectively. A series of characterizations and theoretical calculations (DFT) systematically demonstrated that the excellent photocatalytic performance results from the full spectral response of the material, fast charge separation and transport efficiency, and superior photothermal conversion efficiency of the infrared light. This work will provide a promising insight to the design of S-scheme catalysts with outstanding photocatalytic performance via photothermal assistance and the improved solar energy conversion efficiency.