Construction of Cu cocatalyst on TiO2 for regulating the selectivity of photocatalytic CO2 reduction

Construction of efficient photocatalysts without noble metals for selective photoreduction of CO2 to CH4 remains a challenge. Herein, Cu cocatalyst modified TiO2 photocatalysts were successfully prepared by a convenient solvothermal method. The selectivity of photocatalytic CO2 reduction can be well regulated through valence state and loading amount of Cu. Cu (0) is beneficial to H2 evolution, while high valence Cu contributes to higher CH4 selectivity. The loaded Cu cocatalyst promoted the separation of photogenerated electron-hole and served as the active site for CO2 photoreduction, significantly improving the photocatalytic activity of TiO2. The highest CH4 generation rate of 12.52 μmol g−1 h−1 was achieved on 0.1CT with high CH4 selectivity of 96.9% toward carbon products, which is 397 times higher than pure TiO2 in terms of electrons involved in the reaction. The current work provides significant guidance for the construction of efficient photocatalysts for regulating product selectivity toward CO2 photoreduction.Graphical abstract