Solvothermal fabrication of La-WO3/SrTiO3 heterojunction with high photocatalytic performance under visible light irradiation

A series La-doped WO 3 /SrTiO 3 heterojunctions photocatalyst were successfully prepared using solvothermal method . The as-fabricated heterostructures composite included La-doped WO 3 fluff spheres tightly grew on the surface of SrTiO 3 cubic particles. The crystallanity, structural, morphological and optical features of the catalysts were characterized using several techniques including XRD , XPS , SEM, TEM UV−vis and HRTEM. The photocatalytic activity of the heterojunction was evaluated by the photocatalytic degradation of methyl orange (MO) under visible-light irradiation. The influence of La doping and SrTiO 3 molar ratio on heterojunctions photocatalysts was investigated. Among the as-prepared photocatalysts, the LWS50 sample exhibited the highest photocatalytic activity , almost 100% MO were completely decomposed within 75 min under visible light irradiation (λ > 420 nm). Compared with the pure WO 3 and SrTiO 3 , the enhancement of photocatalytic activity was mainly attributed to the three-dimensional hierarchical structure and the effectively transfer and separation of photogenerated electron–hole pairs in La doped WO 3 and SrTiO 3 heterojunctions