CraftingofplasmonicAunanoparticlescoupledultrathinBiOBrnanosheetsheterostructure:steeringchargetransferforefficientCO2photoreduction

Integrating semiconductor photocatalysts with outstanding visible light absorption and fast surface/interface charge transfer kinetics is still an enormous challenge for efficient CO2 photoreduction. In this work, the Au nanoparticles have been coupled with ultrathin BiOBr nanosheets, the formed heterostructure（Au/BiOBr） possesses a localized surface plasmon resonance（LSPR） and enhances the visible light absorption ability, as well as forms a fast charge transport channel on the interface between Au and BiOBr. Thus, the heterostructure photocatalyst exhibits higher photocatalytic CO2 to CO performance(135.3/16.43 μmol g-1) than that of BiOBr(89.0/6.46 μmol g-1) under 300 W Xe lamp and visible light（λ > 400 nm） irradiation for 5 h, respectively. Finally, the in situ FT-IR spectroscopy revealed CO2 photoreduction process and found that the *COOH is the key intermediate for CO2 to CO. This work provides an effective method to construct multielectron transfer scheme for efficient photocatalytic CO2 reduction.