Morphology-controlled fabrication of Nb5+ doped SrTiO3 for promoting photocatalytic reduction of Cr(VI)

Abstract

To achieve improved photocatalytic activity of Nb5+ doped SrTiO3 (Nb-SrTiO3), Nb-SrTiO3 nanomaterials with different morphologies were prepared via a one-step solvothermal method in ethylene glycol (EG)-H2O mixed solvents. The photocatalytic activities of the as-prepared Nb-SrTiO3 samples were evaluated by the reduction of Cr(VI) under xenon lamp irradiation. The effects of the ratio of VEG/VH2O on the morphology, optical and electronic properties, and photocatalytic activity of Nb-SrTiO3 were investigated. The results indicated that Nb-SrTiO3 with different shapes, including block, sphere, and flower-like structure, could be prepared by controlling the ratio of VEG/VH2O. The sphere-shaped Nb-SrTiO3-3 obtained with the ratio of VEG/VH2O being 4 exhibited stronger light absorption, more efficient separation and transfer of photo-generated charge carriers, and superior photocatalytic activity. Moreover, Nb-SrTiO3-3 can catalyze the reduction of almost 100 % Cr(VI) in the diluted Cr(VI)-containing passivation solution after light irradiation for 25 min, so it holds promise in Cr(VI) wastewater treatment.