Practical liquid phase mixing-calcination synthesis of Nb5+ doped SrTiO3 nanoparticles with elevated photocatalysis

•Facile liquid phase mixing-calcination synthesis of Nb5+ doped SrTiO3 nanoparticles.•Nb-SrTiO3 has improved separation and transfer of photogenerated electrons and holes.•Nb-SrTiO3 has a photocatalytic Cr(VI) reduction activity 4.2 times that of SrTiO3.•Reasons for the improved photocatalytic activity of Nb-SrTiO3 are proposed. The mediocre photocatalytic activity and unpractical preparation methods of SrTiO3 have restricted its practical application as a photocatalyst. Herein, a practical liquid phase mixing-calcination method was designed to synthesize Nb5+ doped SrTiO3 (Nb-SrTiO3) with remarkably elevated photocatalytic activity. Nb-SrTiO3 nanoparticles were synthesized by mixing Sr(NO3)2, NbCl5 and tetrabutyl titanate in deionized water (DW), evaporating the solvent (DW) and calcining the evenly mixed precursors at 700 °C for 4 h. The as-synthesized Nb-SrTiO3 exhibited a photocatalytic activity 4.2 times that of SrTiO3 in the reduction of Cr(VI) under Xenon lamp irradiation. Moreover, Nb-SrTiO3 showed a rather good photocatalytic stability. Nb5+ doping can decrease the particle size and promote the photogenerated carrier separation and transfer of SrTiO3, thereby contributing to heightened photocatalytic activity of Nb-SrTiO3.