Improvement of efficiency and selectivity of CO2 photoreduction over Bi2O2SO4 catalysts with Cu-Bi alloys

Structural design of semiconductor photocatalysts plays an important role in promoting light absorption, molecular activation, and charge separation in the CO 2 reduction reaction, which is beneficial for improving photocatalytic activity. In this paper, a simple photodeposition strategy was employed to load Cu onto Bi 2 O 2 SO 4 and form a Cu-Bi alloy. Under simulated sunlight conditions, the optimal catalyst demonstrates impressive photocatalytic activity and selectivity for CO 2 reduction, with a corresponding yield of 18.8 μmol g -1 h -1 , 15 times higher than that of pure Bi 2 O 2 SO 4 , and CO selectivity reaching 97.1%. The results indicate that metal deposition enhances light absorption utilization efficiency and promotes the separation and transfer of photogenerated carriers. Additionally, the combination of in-situ FT-IR spectra and theoretical calculations reveal the molecular mechanisms of photocatalytic CO 2 reduction. This work discusses the synergistic effect of metal deposition and oxygen vacancies on photocatalytic reduction of CO 2 , providing a feasible method for constructing metal deposition structures with defects.