Hydrogenation of the greenhouse gas CO2 to higher alcohols through catalysis holds great promise for resource transformation in low-carbon energy supply system, but the efficient and selective synthesis of value-added ethanol by a robust heterogeneous catalyst under relatively mild conditions remains a major challenge. Based on our previous work on Au/TiO2 as an active and selective catalyst for ethanol synthesis, we report here that a facile photochemical route can be used for the preparation of anatase TiO2 supported gold catalyst (Au/a-TiO2) for efficient hydrogenation of CO2. Compared with the conventional deposition-precipitation method requiring strong bronsted base and flammable H-2 gas in the complicated and time-consuming process, the photochemical way for the facile preparation of supported gold catalyst shows the advantages of green and energy-saving. Of significant importance is that an impressive space-time-yield of 869.3 mmol g(Au) (-1) h(-1), high selectivity, and excellent stability can be readily attained at 200 degrees C and total pressure of 6 MPa. The effects of irradiation time, solvent, and metal loading or Au particle size on ethanol synthesis are systematically investigated.