Efficient photocatalytic water splitting using Sn-doped SrTiO3 perovskite with Sn at Sr sites

Abstract

The photocatalytic performance of SrTiO3 is significantly limited by intrinsic Ti3+ defects, which act as recombination centers for photogenerated charge carriers. To address this issue, SnO2 doping is employed to modulate the defect structure of SrTiO3. In this work, Sn is successfully incorporated into the Sr sites of the SrTiO3 lattice, predominantly in the form of Sn2+, which effectively suppresses the formation of Ti3+ defects. The optimized Sn-doped SrTiO3 (SSTO-1) sample demonstrates remarkable photocatalytic activity, achieving H2 and O2 evolution rates of 365.5 µmol·h⁻¹ and 180.5 µmol·h⁻¹, respectively, representing a 10.4-fold enhancement in overall water splitting efficiency compared to pure SrTiO3. Detailed characterizations confirm that Sn substitution at Sr sites play a critical role in reducing Ti3+ defects, thereby improving charge carrier separation and photocatalytic efficiency. This work demonstrates that SnO2 doping at appropriate concentrations is a highly effective strategy for enhancing the photocatalytic performance of SrTiO3, offering new insights for the design of advanced photocatalysts for solar energy conversion.