Ultraviolet Radiation Induced Dopant Loss in a TiO2 Photocatalyst

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• 作者：Nicholas P. ChadwickAndreas Kafizas ; Raul Quesada-Cabrera ; Carlos Sotelo-Vazquez ; Salem M. Bawaked ; Mohamed Mokhtar ; Shaeel A. Al Thabaiti ; Abdullah Y. Obaid ; Sulaiman N. Basahel ; James R. Durrant ; Claire J. CarmaltIvan P. Parkin
• 刊名：ACS Catalysis
• 出版年：2017
• 出版时间：February 3, 2017
• 年：2017
• 卷：7
• 期：2
• 页码：1485-1490
• 全文大小：357K
• ISSN：2155-5435

文摘

Doped TiO₂ has been studied with intense interest in recent decades because of its ability to utilize visible wavelengths and enhance the efficiency of photocatalytic processes. Thus, as a class of materials, it is of significant interest for use in environmental ambient energy utilization applications. Using a popular and well-studied form of doped TiO₂ (nitrogen doped) as an example, we show how 28 days of UVA irradiation which is identical in intensity with solar conditions is sufficient to cause the UV induced surface segregation and eventual loss of nitrogen dopant species in TiO₂. This is evidenced by X-ray photoelectron spectroscopy and transient absorption spectroscopy. The loss of interstitial nitrogen dopants correlates with the eventual permanent loss of photocatalytic activity and visible light absorption. The UV induced loss of dopants in a metal oxide is unprecedented and represents a potential problem where the environmental use of doped metal oxides in applications is concerned.