CuO/TiO2 S-Scheme heterostructure for efficient photocatalytic CO2 reduction with nearly 100% CO selectivity

The challenges associated with CO2 adsorption and the lack of product selectivity present significant obstacles to photocatalytic CO2 reduction. In this context, a novel CuO/TiO2 S-Scheme heterostructure has been designed to enhance CO2 conversion efficiency. Across the full spectrum, the CuO/TiO2 heterostructure exhibits optimal catalytic efficiency, nearly 100 % CO selectivity, and robust stability. The superior performance of the CuO/TiO2 heterostructure is attributed to the CuO component, which improves light absorption, modulates the adsorption microenvironment, enhances charge separation, and accumulates more electrons for CO2 reduction reaction. In this study, the 15-CuO/TiO2 demonstrates remarkable photocatalytic CO2 reduction activity, achieving a CO generation rate of 46.9 μmol g−1 h−1, which is significantly higher than that of pure TiO2 (by 5.6 times) and CuO (by 6.7 times), as well as surpassing the majority of previously reported catalytic systems summarized in Table S1. The mechanism of the photocatalytic CO2 reduction process is investigated with the support of theoretical calculations. This work contributes to the development of highly selective catalysts aimed at achieving sustainable photocatalytic CO2 reduction.