▎ 摘　　要

Carbon dioxide (CO2) resulting from the burning of organic carbons has aroused serious concern because of increasing concentrations in the atmosphere and its effect on global warming. Therefore, finding an efficient method for CO2 utilization is important. In this research, CO2 underwent efficient reduction when graphene (GN)-TiO2 was used as a catalyst under visible light irradiation. The radicals involved in the reaction as intermediates were observed by ESR to identify the reduction pathways. Furthermore, the hypothetical pathways were verified by the steady-state approximation model. The calculated rate constants of the final products and intermediates (including radicals) indicated that the formation of CH3OH was mainly derived from center dot CO- rather than from HCOOH. Furthermore, the effects of GN loading, catalyst loading, and light source were also discussed. Optimal performance was achieved at 0.4 g L-1 of 40% GN-TiO2 loading under visible light irradiation.