Preparation and photocatalytic activity of visible light-active sulfur and nitrogen co-doped SrTiO₃

Nitrogen and sulfur co-doped SrTiO₃ was prepared by high energy grinding of the mixture of SrTiO₃ and thiourea. A new band gap in visible light region (522 nm) corresponding to 2.37 eV could be formed by the co-doping. The photocatalytic activity for nitrogen monoxide oxidation of SrTiO₃ in visible light region especially in the long wavelength range (λ > 510 nm) could be improved greatly. Under the irradiation of light with wavelength larger than 510 nm, the photocatalytic activity of nitrogen and sulfur co-doped SrTiO₃ was 10.9 times greater than that of pure SrTiO₃. The high visible light photocatalytic activity of this substance may be due to the formation of a new band gap that enables to absorb visible light effectively.