Shedding Light on Aging of N-Doped Titania Photocatalysts

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• 作者：Alexey Tarasov ; Anton Minnekhanov ; German Trusov ; Elizaveta Konstantinova ; Alexandr Zyubin ; Tatiana Zyubina ; Alexey Sadovnikov ; Yury Dobrovolsky ; Eugene Goodilin
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：August 13, 2015
• 年：2015
• 卷：119
• 期：32
• 页码：18663-18670
• 全文大小：612K
• ISSN：1932-7455

文摘

A detailed analysis of nitrogen dopant behavior in nanostructured microspheres of the TiO₂ photocatalyst obtained by the thermally assisted reactions in aqueous sprays method has been performed for the first time using electron paramagnetic resonance, X-ray photoelectron spectroscopy, and UV鈥搗is spectroscopy and is supported by theoretical simulation of possible defect structures. The nitrogen species were found to undergo the N^{鈥?/sup> to N鈥?/sup> transformation during sample storage under different conditions, with an activation energy of about 0.45 eV. Three main possible evolution pathways for the dopant state were identified and discussed. It was established that the most probable transformation consists of migration of an oxygen vacancy site to an interstitial nitrogen atom followed by the formation of a nonparamagnetic substitution nitrogen center. Possible diffusion routes of oxygen vacancy and corresponding energy barriers were estimated and found to be in agreement with experimental observations.}