Study on the mechanisms of photoinduced carriers separation and recombination for Fe³⁺–TiO₂ photocatalysts

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• 作者：Baifu Xin ; Zhiyu Ren ; Peng Wang ; Jia Liu ; Liqiang Jing ; Honggang Fu
• 关键词：Fe³⁺ doped TiO₂ ; Photocatalysis ; Photoinduced carrier characteristics
• 刊名：Applied Surface Science
• 出版年：2007
• 期刊代码：6_01694332
• 类别：ms
• 出版时间：28 February 2007
• 卷：253
• 期：9
• 页码：4390-4395
• 文件大小：459 K

摘要

The iron(III)-ion doped TiO₂ (Fe³⁺–TiO₂) with different doping Fe³⁺ content were prepared via a sol–gel method. The as-prepared Fe³⁺–TiO₂ nanoparticles were investigated by means of surface photovoltage spectroscopy (SPS), field-induced surface photovoltage spectroscopy (FISPS), and the photoelectrochemical properties of Fe³⁺–TiO₂ catalysts with different Fe³⁺ content are performed by electrical impedance spectroscopy (EIS) as well as photocatalytic degradation of RhB are studied under illuminating. Based on the experiment results, the mechanism of photoinduced carriers separation and recombination of Fe³⁺–TiO₂ was revealed: that is, the Fe³⁺ captures the photoinduced electrons, inhibiting the recombination of photoinduced electron–hole pairs, this favors to the photocatalytic reaction at low doping concentration (Fe/Ti ≤ 0.03 mol%); while Fe³⁺ dopant content exceeds 0.03 mol%, Fe₂O₃ became the recombination centers of photoinduced electrons and holes because of that the interaction of Fe₂O₃ with TiO₂ leads to that the photoinduced electrons and holes of TiO₂ transfer to Fe₂O₃ and recombine quickly, which is unfavorable to the photocatalytic reaction.