Solvothermal synthesis nitrogen doped SrTiO3 with high visible light photocatalytic activity

Nitrogen (N)-doped SrTiO3 (SrTiO3−xNy) photocatalysts were synthesized by a solvothermal method using Sr(NO3)2·4H2O and Ti(OC3H7)4 as starting materials in KOH solution, hexamethylenetetramine as a source of nitrogen. The physicochemical properties of the photocatalysts were analyzed by Field-Emission Scanning Electron Microscopy (FE-SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area and ultraviolet–visible spectroscopy (UV–vis). The photocatalytic activity of the SrTiO3−xNy was evaluated by degrading methyl orange (MO) dye under a mercury lamp xenon lamp irradiation, respectively. The results proved that the N doping amount had an important effect on the photocatalytic activity of the catalysts. The pH effects on the photocatalytic degradation were also investigated. The prepared SrTiO3−xNy photocatalyst showed excellent photocatalytic activity for the decomposition of MO under visible-light irradiation, being superior to that of pure SrTiO3 or commercial TiO2 (P25) powders. After five cycles, the photocatalytic activity of the SrTiO3−xNy showed no significant decrease, which indicated that the photocatalysts were stable under visible light irradiation.