Photogenerated charges transfer across the interface between NiO and TiO₂ nanotube arrays for photocatalytic degradation: A surface photovoltage study

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• 作者：Libo Hou^a ; Shuo Li^a ; Yanhong Lin^a ; Dejun Wang^a ; ^b ; Tengfeng Xie^a ; ^{xietf@jlu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Photocatalytic ; Surface photovoltage ; Photogenerated charges ; Interfacial electric field ; Work function
• 刊名：Journal of Colloid and Interface Science
• 出版年：2016
• 出版时间：15 February 2016
• 年：2016
• 卷：464
• 期：Complete
• 页码：96-102
• 全文大小：1907 K

文摘

To better understand the behavior of photogenerated charges in the composite photocatalyst interface is beneficial to the designing of effective photocatalyst for photocatalytic reaction. In our work, the separation and transfer process of photogenerated charges in NiO/TiO₂ nanotube arrays (NiO/TiO₂ NTAs) has been studied by surface photovoltage (SPV) spectroscopy and transient photovoltage (TPV) measurement. Through the experimental results analysis, we find that an interfacial electric field is formed at NiO/TiO₂ NTAs interface, which is attributed to the work function difference between NiO and TiO₂ NTAs. The photogenerated holes in TiO₂ can transfer to the NiO layer along the interface electric field under the ultraviolet irradiation. A large amount of photogenerated holes can be separated effectively and then prolonged the holes lifetime to participate in the photocatalytic oxidation reaction. The above results show that the favorable hole-collecting process of NiO in the surface of TiO₂ NTAs is the main factor being responsible for the increase the photocatalytic efficiency.