Thermally assisted photocatalysis: oxygen vacancy-mediated enhanced photothermal synergistic CO2 reduction over Cu-Ni Co-doped Bi2MoO6

This study employs a Cu–Ni co–doping strategy to construct a Bi 2 MoO 6 photothermal synergistic catalyst, achieving highly efficient conversion of CO 2 reduction. Under ultraviolet–visible (UV–Vis) xenon lamp irradiation and 200 °C external heating conditions, the optimal sample (3Cu-6Ni-Bi 2 MoO 6 ) exhibited CO and CH 4 yields of 293.16 μmol·g −1 and 98.43 μmol·g −1 respectively, within 4 h, representing 6.8-fold and 5.3-fold increases compared to the undoped sample. The significant enhancement in CO 2 conversion activity can be attributed to the following factors: (1) Co-doping with Cu 2+ and Ni 2+ induces lattice distortion and oxygen vacancy formation, generating defect energy levels near the valence band edge. This reduces the bandgap to 2.1 eV, thereby broadening the visible light absorption range; (2) Oxygen vacancy defects provide highly efficient CO 2 adsorption and activation sites; (3) Doping with Cu and Ni enhances the separation and transport efficiency of photogenerated carriers.