Synergistic effect of Cu2+ and Cu+ in SrTiO3 nanofibers promotes the photocatalytic reduction of CO2 to methanol

Photocatalytic reduction of CO 2 to methanol over SrTiO 3 (ST) perovskite oxide is considered as a promising method to alleviate environment and energy problems at the same time. Meanwhile, the inducing of Cu plays an important role in photocatalytic activity and selectivity. Herein, a series of SrTi 1-x Cu x O 3 -H 2 (STCu x -H, x = 0.04, 0.06, 0.08, and 0.1) nanofiber catalysts were prepared by electrospinning combined with in-situ dissolution strategy. Cu x O dissolved in situ on a one-dimensional nanofiber structure could realize more active sites exposed and convenient directional movement of electrons, simultaneously. The unique structure facilitates the enhancement of photocatalytic activity and the improvement of selectivity. The methanol yield of STCu 0.08 -H nanofiber catalyst upped to 5.38 ± 0.19 μmol·g −1 ·h −1 , which was twice that of ST. Moreover, the photocatalytic activity did not decrease significantly after four times of reuse. The characterization further demonstrated that STCu 0.08 -H had stronger light response ability and faster electron transfer ability than ST under the synergistic action of Cu 2+ and Cu + . STCu 0.08 -H had superior CO 2 adsorption, activation ability, and electronic reduction capability by DFT calculation. This study provided a new idea about the design of perovskite oxide nanofiber for photocatalytic CO 2 reduction.