Photocatalysis of a unique hollandite compound was investigated for the reductions of nitric oxide (NO) in gas phase and nitrate ion (NO3 -) in water with reducing agents under UV radiation. Both NO and NO3 - are hazardous chemicals to human. Recently, it was reported that titanium oxide (TiO2) photocatalyst performed the oxidative decomposition of NO to NO3 -. However, an ideal photocatalytic removal of NO would be the reductive decomposition of NO to N2 and O2 without by-products. In this study, the surface activity of the unloaded hollandite, prepared by sol-gel method, was applied to the photocatalytic reaction. The present photocatalysis was quantitatively examined by using on-line mass spectrometry and ion chromatography, and the adsorption species on the hollandite surface was analyzed by in-situ IR spectroscopy. UV-irradiated hollandite exhibited high selectivity for the formation of N2 in the reductive decomposition of NO. Moreover, this catalyst also showed the reductive decomposition of NO3 - to NO2 - and N2 in water. In particular, the photocatalytic decomposition of NO3 - would be a new pathway that has not been reported for popular photo-catalysts such as unloaded TiO2. Probably, this type compound is expected to have potentialities as a new type photocatalyst.
|Number of pages||6|
|Journal||Materials Research Society Symposium - Proceedings|
|Publication status||Published - 1 Jan 1999|
|Event||Proceedings of the 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998' - Boston, MA, USA|
Duration: 30 Nov 1998 → 3 Dec 1998