Bi‐, Y‐Codoped TiO2 for Carbon Dioxide Photocatalytic Reduction to Formic Acid under Visible Light Irradiation

Abstract Bi‐ and Y‐codoped TiO 2 photocatalysts were synthesized through a sol‐gel method, and they were applied in the photocatalytic reduction of CO 2 to formic acid under visible light irradiation. The results revealed that, after doping Bi and Y, the surface area of TiO 2 was increased from 5.4 to 93.1 m 2 /g when the mole fractions of doping Bi and Y were 1.0% and 0.5%, respectively, and the lattice structures of the photocatalysts changed and the oxygen vacancies on the surface of the photocatalysts formed, which would act as the electron capture centers and slow down the recombination of photo‐induced electron and hole. The photocurrent spectra also proved that the photocatalysts had better electronic transmission capacities. The HCOOH yield in CO 2 photocatalytic reduction was 747.82 μmol/g cat by using 1% Bi‐0.5% Y‐TiO 2 as a photocatalyst. The HCOOH yield was 1.17 times higher than that by using 1% Bi‐TiO 2 , and 2.23 times higher than that by using pure TiO 2 . Furthermore, the 1% Bi‐0.5% Y‐TiO 2 showed the highest apparent quantum efficiency (AQE) of 4.45%.