Rare earth doping BaTiO3 for enhancing photocatalytic CO2 reduction performance

The light absorption capacity has a crucial effect on photocatalytic activity as one of the essential properties of photocatalysts. Herein, a series of tetragonal phase Ba[Formula: see text]MxTiO3 (M = Eu, Ce, Sm, Gd, La) photocatalysts were synthesized by a hydrothermal method. Among rare earth dopants, Ba[Formula: see text]SmxTiO3 exhibits a smaller grain size ([Formula: see text] [Formula: see text]nm), and provides more sites for the adsorption and activation of CO2, compared to pristine BaTiO3. The introduction of Sm ion extends the optical response range of BaTiO3 to the visible region and reduces the band gap. Under 300[Formula: see text]W Xe lamp, the 4[Formula: see text]h CO and CH4 yields of Ba[Formula: see text]SmxTiO3 catalysts increased to [Formula: see text]mol[Formula: see text] ⋅ g[Formula: see text] and 0.46[Formula: see text] [Formula: see text]mol[Formula: see text] ⋅ [Formula: see text]g[Formula: see text], respectively, which were 1.89 and 0.76 times that of the pristine BaTiO3. This work provides insights for designing rare earth-doped photocatalysts and realizing efficient conversion of solar fuel.