Hydrothermal synthesis of Nb5+-doped SrTiO3 mesoporous nanospheres with greater photocatalytic efficiency for Cr(VI) reduction

The Nb5+-doping strategy was adopted to enhance the photocatalytic efficiency of SrTiO3 to overcome the limitation for its practical photocatalytic applications. Different amounts of Nb5+ doped SrTiO3 (Nb-SrTiO3) mesoporous nanospheres were synthesized via a convenient hydrothermal approach. The photocatalytic reduction of aqueous Cr(VI) using the Nb-SrTiO3 products under xenon lamp irradiation was investigated. Results indicated that 3% Nb-SrTiO3 was the optimum product, which exhibited a photocatalytic efficiency 3 times as much as that of SrTiO3 and a fair reuse stability. Moreover, 3% Nb-SrTiO3 also demonstrated higher photocatalytic efficiency than many other metal cations doped SrTiO3 synthesized via the same process and a number of previously reported photocatalysts. The best photocatalytic activity of 3% Nb-SrTiO3 was found to be predominantly due to its most efficient separation and transfer of photogenerated holes and electrons. This study suggests that Nb-SrTiO3 is a potential efficient photocatalyst for the remediation of Cr(VI)-contaminated water.