Efficient photocatalytic reduction of CO2 into liquid products over cerium doped titania nanoparticles synthesized by a sol–gel auto-ignited method

• The CH3OH yield of CT reached 188 μmol g− 1 h− 1 under UV light irradiation.
• The impact of Ce doping on the structural properties of CT was discussed.
• The role of Ce species in the CO2 photocatalytic reduction was investigated.
• The influence of product desorption on the deactivation of CT catalyst was discussed.

Cerium doped TiO2 nanoparticles were synthesized through a simple sol–gel auto-ignited method. Ce doping inhibited the growth of TiO2 particles and increased the surface area of the catalysts. The catalyst was well characterized and used as photocatalysts to convert CO2 and H2O into hydrocarbons, including CH3OH, HCHO, and CH4, in liquid phase. CH3OH was found to be the primary product with a highest yield of 188 μmol/g obtained by 1% Ce doped TiO2 catalyst after UV irradiation for 8 h, which was much higher than that of pure TiO2 and P25. The selective formation of CH3OH can be ascribed to the compromise between charge transfer and thermodynamics. The introduction of CeO2 can enhance the chemisorbed oxygen on the surface of the catalyst and the existence of Ce3 +/Ce4 + mixture can effectively inhibit the recombination of photogenerated electron–hole pairs, resulting in remarkable activity of cerium doped TiO2 catalyst. Desorption of the reaction products plays an important role on the deactivation of the catalyst.

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