Photocatalytic decomposition of N2O on highly dispersed Ag+ ions on TiO2 prepared by photodeposition

Nitrous oxide (N2O) was photocatalytically decomposed on Ag-photodeposited TiO2 in the presence of methanol vapor. The N2O decomposition activity of Ag-photodeposited TiO2 was much higher than that of Ag-loaded TiO2 prepared by deposition-precipitation or impregnation methods. The difference in the N2O decomposition activity between the preparation methods was discussed in terms of the surface conditions observed by transmittance electron microscopy and X-ray photoelectron spectroscopy. The N2O decomposition activity depended on the amount of photodeposited Ag, and the TiO2 loaded with only 0.16 wt% Ag has revealed the highest level of activity. Highly dispersed Ag+ ions prepared by photodeposition were effective for the photocatalytic decomposition of N2O. In the deposition-precipitation or impregnation methods, Ag+ ions aggregated to form Ag particles and the N2O decomposition activity of these catalysts showed a low level of efficiency. Nitrogen of N2O was reduced into N-2 gas, whereas oxygen was released as CO or CO2 by the reaction with methanol or its derivatives, (C) 2000 Academic Press.