Visible light driven photocatalytic reduction of CO2 on Au-Pt/Cu2O/ReS2 with high efficiency and controllable selectivity

Photocatalytic conversion of CO2 to value-added chemicals and fuels is a green and sustainable approach to solve the problems of CO2 concentration increment and fossil fuels shortage. Employing photocatalysts with high catalytic activity and selectivity to realize CO2 conversion has attracted extensive attention. However, the efficiency of photocatalysts is still unsatisfied and the selectivity of products is hard to be regulated, hindering their practical applications in large scale commercial purpose. In this work, for the first time, the Au and Pt was co-deposited on the heterostructure consisted of Cu2O quantum dots and ReS2 nanosheets to achieve high efficiency and controllable selectivity during CO2 photoreduction. The Au-Pt/Cu2O/ReS2 photocatalysts show superior efficiency of CO2 reduction than that of Au/Cu2O/ReS2, Pt/Cu2O/ReS2, Cu2O/ReS2, Cu2O. Such distinct improvement is attributed to the indirect Z-scheme mechanism and Schottky junction effect. Moreover, the synergetic effect of Au and Pt plays an important role of improving the photocatalytic activity, and the Au1-Pt5/Cu2O/ReS2 exhibits the highest Relectron of 516.86 μmol/g during one hour of visible light illumination, which is much larger than many recently reported photocatalysts under comparable condition. Meanwhile, the selectivity of CO and CH4 is effortlessly tunable from 0 to 100% by modulating Au/Pt metal mass ratio due to the strong CO adsorption on Pt metals and the intensive interaction between Au and Pt atoms at the Au/Pt interface. This controllable selectivity provides admirable strategy to tune the component proportion of the gas products for the subsequent conversion into high value-added chemicals or liquid fuels. Our study proposes novel and deep insights into the design and fabrication of practical photocatalysts with high catalytic activity and controllable selectivity to perform efficient CO2 photoconversion.