Fabrication of novel perovskite-type Sr2Ta(Fe1−xGax)O6 nanoparticles with high visible-light photocatalytic activity

Abstract

Novel Sr₂Ta(Fe_1−xGa_x)O₆ perovskite photocatalysts were successfully synthesized by a simple one-step sol–gel method and characterized for structural, morphological and optical properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), Brunauer Emmett Teller (BET) and UV-visible (UV-vis) diffused reflectance spectroscopy (DRS), respectively. A sample of Sr₂Ta(Fe_0.8Ga_0.2)O₆ calcined at 900 °C for 10 h exhibited the highest photocatalytic activity, and the photodegradation rate of methylene blue (MB) achieved 96.2% after 2 h visible light irradiation. The enhanced photocatalytic performance and outstanding stability were attributed to the appropriate crystallinity, Ga³⁺ doping content and the special perovskite structure. This Ga-doping created impurity levels in the forbidden band, which shortened the band gap and generated more photoactive sites to facilitate photocatalytic activity.