▎ 摘　　要

The most efficient method of converting CO2 to hydrocarbon fuels is a photocatalyst-based process, in which the efficient charge transfer and the recombination rate of the electron-hole pair are important parameters that determine the catalytic activity of the photocatalyst. Novel structured ternary photocatalyst keeps more advantage than binary material because it has strong light absorption rate and enhanced photocatalytic potency. Based on the abovementioned superiority, our study proposes a new model of a ternary nanocomposite synthesized by solvothermal methods consisting of graphene, TiO2, and chalcogenide-quaternary nanostructures. The high surface area of 2D-structured graphene can be a bridge between the semiconductor and a quaternary, increases light absorption, and enhances the photogenerated charge transfer. The preparation of quaternary nanocomposite was based on metallic citrate polymerization which used ethylene glycol (C2H6O2) and citric acid (C6H8O7) as chelate cations. The morphology and charge carrier properties of the ternary nanocomposite were analyzed by physical characterization equipment, and the catalytic activity was determined by the reduction experiment of CO2 with different electron-scavengers and different electron-donor scavengers were used in the experiment. The final yield of methanol under UV light was 8.62% and 7.23%, and the yield under visible light was 6.25% and 5.92%, respectively. In addition, the stability and reusability of the photocatalyst were analyzed by a six-times cycling test without loss of methanol formation by CO2 evolution. The catalytic activity test confirmed that the ternary photocatalyst had high catalytic activity and stability, and this study confirms that the newly modeled nanomaterials are active materials that can be used for applications in environmental pollution removal and production of hydrocarbon fuels.