Efficient electron transport at the perovskite nanodots interface facilitates CO2 photoreduction.

ABSTRACT

How to achieve controllable preparation of heterostructure and in-situ optimize the interface and internal electron transfer by a fast and economic synthesis method has become a big challenge in the practical application of photocatalysis. Herein, an island-shaped SrTiO3 (STO) perovskite nanodots and TiO2 (T) compounded S-scheme SrTiO3/TiO2 (ST) heterostructure was successfully developed. During the millisecond reaction process, the decomposed Sr2+ penetrated into the TiO2 lattice causing the lattice expansion and inducing local atomic rearrangements, resulting in the generation of STO phase. Owing to the synergy of the efficient electron transport at the perovskite nanodots interface and the stronger reduction capacity, the performance of the optimized ST1 sample is greatly improved to 86.90 µmol g-1 for CO2-to-CO and 21.31 µmol g-1 for CO2-to-CH4. The utilization of electrons reached up to 119.74 µmol g-1 h-1, which was 3.13 times higher than that of T. Detailed characterizations and density functional theory (DFT) calculations proof that the formation of intermediates HCOO- and CO32- is the key to the performance improvement critically. Overall, this work originally reports a feasible strategy for flame synthesis of S-scheme heterostructure photocatalyst.