Study on the Effect of Bi Metal-Doped TiO2 on the Performance of Photothermal Catalytic Reduction of CO2 to Renewable Synthetic Fuels

In today’s context of carbon-neutral carbon peaking and uneven distribution of global fossil energy, future-oriented artificial photosynthesis may become the key to solving the problem, and the realization of photothermal coupling catalytic one-step reduction of CO2 and H2O to renewable synthetic fuels is a more critical step in the selection and design of catalysts and the study of the reaction mechanism. Among them, TiO2 is widely used in the photothermal reduction of CO2 because of its excellent photothermal chemical properties. However, the photothermal catalytic mechanism of TiO2 is not clear at present, and there is a lack of effective modification to enhance the catalytic activity. In this study, TiO2 nanoribbon materials with an anatase phase were synthesized by hydrothermal modification of TiO2 carriers, and the doping of metal Bi was carried out by various methods on this basis. The performance and selectivity of the modified TiO2 catalysts were evaluated by photothermal catalytic reduction of CO2 and H2O, while the physicochemical properties and photochemistry were determined by XRD, Raman, BET, SEM, EDS mapping, TEM, XPS, UV–vis DRS, PL, TR-PL, CO2-TPD, and in situ DRFITS. The catalysts were analyzed by in situ characterization techniques to reveal the effects of carrier modification, semiconductor compounding, metal loading, and doping on the catalytic performance, physicochemical properties, and photothermal properties of the catalysts and then to explain the mechanism of CO2 catalytic reduction, which provides theoretical guidance and data support to improve the selection and design of catalysts.