Insight of the State for Deliberately Introduced A-Site Defect in Nanofibrous LaFeO₃ for Boosting Artificial...

Perovskite-type LaFeO₃ is regarded as a potentially efficient visible-light photocatalyst owing to its narrow bandgap energy and unique photovoltaic properties. However, the insufficient active sites and the unsatisfactory utilization of photogenerated carriers severely restrict the realistic application of pure LaFeO₃. Herein, we fabricated a series of La_xFeO_3-δ nanofibers (x = 1.0, 0.95, 0.9, 0.85, 0.8) with an A-site defect via sol-gel combined with the electrospinning technique. Wherein, the nonstoichiometric La_0.9FeO_3-δ possessed the highest CH₃OH yield of 5.30 μmol·g^-1·h^-1 with good chemical stability. A series of advanced characterizations were applied to investigate the physicochemical properties and charge-carrier behaviors of the samples. The results illustrated that the one-dimensional (1D) nanostructures combined with the appropriate concentration of vacancy defects on the surface contributed to the radial migration of photogenerated carriers, inhibited the recombination of carriers, and provided more CO₂ adsorption-activation sites. Furthermore, density functional theory (DFT) calculations were employed to reveal the influence mechanism of vacancy defects on LaFeO₃. This work provides a strategy to enhance the performance of photocatalytic CO₂ reduction by modulating the induced oxygen vacancies caused by the A-site defect in perovskite oxides.