Efficient visible-light-driven CO2 reduction mediated by novel Au-doped BiOBr nanosheets

Photocatalytic reduction of CO2 into valuable resources presents an efficient solution to mitigate the energy crisis and effects of climate change. However, the low efficiency of photocatalytic CO2 reduction of photocatalysts under visible light irradiation limits their industrial applications. Bismuth oxybromide (BiOBr) is a typical visible-light-driven photocatalyst with an appropriate band gap, but the charge separation efficiency still needs to be improved. In this work, the Au-doped BiOBr nanosheets with enhanced electrochemical characteristics were successfully synthesized through a simple one-step hydrothermal procedure. After Au-doping modification, the charge separation efficiency of BOB-Au-I sample were measured as 2.5 times than that of BiOBr nanosheets. And the BOB-Au-I samples exhibited an outstanding photocatalytic capacity for converting CO2 to CO with a yield rate of approximately four times higher than that of BOB nanosheets under visible light irradiation. Furthermore, the mechanism of CO2 reduction was elucidated through in situ Fourier-transform infrared spectroscopy. This study provides a facile method for achieving Au-doping modification of BiOBr nanosheets for efficient reduction of CO2.