Enhanced Visible-Light Photoactivities of Perovskite-Type LaFeO3 Nanocrystals by Simultaneously Doping Er3+ and Coupling MgO for CO2 Reduction

摘要

The use of solar energy to convert CO2 into chemical fuels not only can create renewable energy but also can alleviate the greenhouse effect. In this work, MgO/LaFeO3 : Er3+ composites were prepared, and their photocatalytic CO2 reduction capability was tested under visible-light irradiation. The MgO/LaFeO3 : Er3+ composites displayed improved charge carrier separation efficiency, higher CO2 adsorption capacity, and increased photoactivities for photocatalytic CO2 reduction to CO and CH4 (71.52 mu mol g(-1) h(-1) and 5.54 mu mol g(-1) h(-1), respectively). As a comparison, the production rates of CO and CH4 are 29.36 mu mol g(-1) h(-1) (CO) and 4.13 mu mol g(-1) h(-1), respectively for pure LaFeO3. The enhanced photoactivities are attributed to the increased electron-hole separation rate resulting from the Er3+ doping and improved CO2 adsorption capacity by MgO coupling. This work thus identifies a novel approach towards highly efficient photocatalysts for CO2 reduction.