Preparation of the visible light responsive N3--doped WO3 photocatalyst by a thermal decomposition of ammonium paratungstate

The nitrogen doped WO3 (N-WO3) photocatalyst was successfully prepared by a thermal decomposition of an ammonium paratungstate [(NH4)(10)W12O41 center dot 5H(2)O]containing NH4+ ions as a nitrogen source. The N-WO3 prepared at 673-873 K efficiently absorbed visible light in longer wavelength regions as compared to a commercial N-free WO3. Although small amount of Pt particles must be deposited on the catalyst surfaces, the N-WO3 photocatalysts were found to decompose gaseous methanol into CO2 and H2O under visible or solar light irradiations. As well as, the Pt particles on the N-WO3 surfaces to enhance the photocatalytic activity showed an oxidation catalysis property at low temperatures of 323-333 K. These results suggest that the N-WO3 deposited with Pt particles can effectively utilize the sunlight as light and/or heat sources. (C) 2011 Elsevier B.V. All rights reserved.