Efficient photocatalytic reduction of CO2 by amine-functionalized g-C3N4

Abstract Photocatalytic conversion of CO 2 into hydrocarbon fuels using semiconductor photocatalysts has attracted great attention, which is considered as a promising approach to resolve the energy shortage and greenhouse effect. In this work, amine-functionalized g-C 3 N 4 was prepared by heating urea at 500 °C, with a subsequent functionalization treatment by monoethanolamine solution. The amine-functionalized g-C 3 N 4 exhibits improved photocatalytic performance on CO 2 photoreduction, which can be attributed to the enhanced CO 2 adsorption capacity. The optimized photocatalyst shows much higher CO 2 conversion efficiency as compared to pure g-C 3 N 4 under the same conditions, with a CH 4 -production rate of 0.34 μmol h −1  g −1 and CH 3 OH-production rate of 0.28 μmol h −1  g −1 . This work demonstrates the surface amine functionalization is a successful strategy to improve the CO 2 adsorption capacity of g-C 3 N 4 for the enhancement of CO 2 photoreduction activity.