Effects of Mo sources on Mo doped SrTiO3 powder prepared by spray pyrolysis for H2 evolution under visible light irradiation

SrTiO3 was doped with three types of molybdenum ions (Mo6+, Mo4+, and Mo2+) by spray pyrolysis. The molybdenum ions narrowed the band gap of SrTiO3 to allow hydrogen evolution under visible-light irradiation. The molybdenum-doped SrTiO3 photocatalyst prepared from MoO2 (0.4 mol%) exhibited hydrogen evolution up to a rate of 1410.3 mol g(-1) h(-1) with an induction period of 1 h. The use of MoO2 resulted in SrTiO3 doping by Mo6+ and Mo4+ ions, which enhanced the hydrogen evolution by forming 4d-like states under the conduction band. The ionic structure of SrTiO3 doped with Mo4+ and Mo4+ could be expressed as Sr[Ti-1(-x-y)4+(Mox4+Moy6+)]O-3 from the X-ray photoelectron spectra. (C) 2016 Elsevier B.V. All rights reserved.