Preparation and characterization of nitrogen doped SrTiO3 photocatalyst

Nitrogen doped SrTiO3 powders were prepared by the mechanochemical reaction of SrTiO3 and 20 wt.% of three kinds of doping sources, hexamethylenetetramine, urea, and ammonium carbonate using a high energy planetary ball mill, followed by calcination at 400 °C for 1 h. The photocatalysis of nitrogen doped SrTiO3 powders under the irradiation of wavelength λ>400 nm and near ultraviolet light regions (λ>290 nm) greatly changed depending on particle size, specific surface area and porosity. The absorption of visible light increased with increasing nitrogen content doped in SrTiO3 lattice. Nitrogen monoxide elimination ability of SrTiO3 could be greatly improved by nitrogen doping. The photocatalytic activity of nitrogen doped SrTiO3 made by 20 wt.% hexamethylenetetramine-SrTiO3 under light λ>400 nm irradiation was about 3.5 and 1.4 times higher than those of pure SrTiO3 and commercial titania powder (Degussa P-25).