Defect density modulation of La2TiO5: An effective method to suppress electron-hole recombination and improve photocatalytic nitrogen fixation

Surface defects were introduced into La 2 TiO 5 nanoparticles, which possessed the following obvious advantages: (1) improving the absorption capacity of visible light and broadening the spectral response range; (2) the formation of defect energy levels is conducive to the transition of electrons; (3) oxygen vacancy can further improve the photocatalytic activity. The yield of photocatalytic nitrogen fixation under simulated sunlight could reach 158.13 μmol·g −1 ·h −1 and the photocatalytic mechanism was systematically studied. • Defective La 2 TiO 5 nanpparticles with broad visible light absorption were obtained. • Without any precious metal co-catalyst, the NH 3 yield of photocatalyst under simulated sunlight irradiation was 158.13 μmol·g −1 ·h −1 . Highly active and efficient photocatalysts are crucial for the exploration of ammonia synthesis because of the serious problem of energy deficiency. La 2 TiO 5 (LTO) perovskite materials have great advantages in the field of photocatalytic nitrogen fixation because of the broadly diversified properties. The rational design of surface defect is a valid method to modulate photoinduced charge traps and create defect energy levels, especially it is an effective way to suppress the photoinduced charge recombination. Herein, LTO was obtained by a simple sol-gel method and was further reduced by NaBH 4 to introduce oxygen defect on its surface. UV–vis spectra proved that the surface defects could reduce the band gap value of samples, which is beneficial for improving photocatalytic nitrogen fixation activity. For the best photocatalytic samples with good cycle stability, the nitrogen fixation rate is 158.13 μmol·g −1 ·h −1 . The mechanism of photocatalytic nitrogen fixation was proposed by the PL, XPS, and PEC results, which provided possibilities for exploring more promising perovskite catalysts in the field of nitrogen fixation.