Chemistry of NOx on TiO2 Surfaces Studied by Ambient Pressure XPS: Products, Effect of UV Irradiation, Water, and Coadsorbed K+
详细信息 查看全文
- 作者：Olivier Rosseler ; Mohamad Sleiman ; V. Nahuel Montesinos ; Andrey Shavorskiy ; Valerie Keller ; Nicolas Keller ; Marta I. Litter ; Hendrik Bluhm ; Miquel Salmeron ; Hugo Destaillats
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2013
- 出版时间：February 7, 2013
- 年：2013
- 卷：4
- 期：3
- 页码：536-541
- 全文大小：451K
- 年卷期：v.4,no.3(February 7, 2013)
- ISSN：1948-7185
文摘
Self-cleaning surfaces containing TiO2 nanoparticles have been postulated to efficiently remove NOx from the atmosphere. However, UV irradiation of NOx adsorbed on TiO2 also was shown to form harmful gas-phase byproducts such as HONO and N2O that may limit their depolluting potential. Ambient pressure XPS was used to study surface and gas-phase species formed during adsorption of NO2 on TiO2 and subsequent UV irradiation at 位 = 365 nm. It is shown here that NO3鈥?/sup>, adsorbed on TiO2 as a byproduct of NO2 disproportionation, was quantitatively converted to surface NO2 and other reduced nitrogenated species under UV irradiation in the absence of moisture. When water vapor was present, a faster NO3鈥?/sup> conversion occurred, leading to a net loss of surface-bound nitrogenated species. Strongly adsorbed NO3鈥?/sup> in the vicinity of coadsorbed K+ cations was stable under UV light, leading to an efficient capture of nitrogenated compounds.