Preparation method and application of tin-doped cobaltosic oxide material with oxygen vacancies for efficient photocatalytic reduction of CO2

The invention provides a preparation method of a material with the performance of photocatalytic reduction of carbon dioxide (CO2). The material can be well applied to a system for selectively synthesizing methane (CH4) through photocatalytic conversion of CO2. The preparation method comprises the following steps: respectively taking cobalt nitrate hexahydrate (Co (NO3) 2.6 H2O) and tin tetrachloride pentahydrate (SnCl4. 5H2O) as a cobalt source precursor and a tin source precursor, adding the cobalt nitrate hexahydrate (Co (NO3) 2.6 H2O) and the tin tetrachloride pentahydrate (SnCl4. 5H2O) into an aqueous solution of ammonium carbonate ((NH4) 2CO3), uniformly mixing, and then carrying out oil bath, drying, calcining and other steps to obtain the tin-doped cobaltosic oxide (x-Sn/Co3O4) hybrid material with oxygen vacancies. According to the method disclosed by the invention, the doping amount of tin can be simply controlled by controlling the amount of the input SnCl4. 5H2O, and some oxygen vacancies can be i