Defect-Induced Band Gap Narrowed CeO2 Nanostructures for Visible Light Activities

详细信息    查看全文

• 作者：Mohammad Mansoob Khan ; Sajid Ali Ansari ; Debabrata Pradhan ; Do Hung Han ; Jintae Lee ; Moo Hwan Cho
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：June 11, 2014
• 年：2014
• 卷：53
• 期：23
• 页码：9754-9763
• 全文大小：590K
• 年卷期：v.53,no.23(June 11, 2014)
• ISSN：1520-5045

文摘

This work reports an electron beam irradiation (30 kGy and 90 kGy) approach to narrow the band gap of the pristine CeO₂ nanostructure (p-CeO₂) to enhance their visible light activity through defect engineering. This was confirmed by diffuse reflectance spectroscopy, photoluminescence, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Brunauer鈥揈mmett鈥揟eller, electrochemical impedance spectroscopy, and linear scan voltammetry. XPS revealed changes in the surface states, composition, Ce⁴⁺ to Ce³⁺ ratio, and other defects in the modified CeO₂ nanostructures (m-CeO₂). The m-CeO₂ exhibits excellent photocatalytic activities by degrading 4-nitrophenol and methylene blue in the presence of visible light (位 > 400 nm) compared to the p-CeO₂. The optical, photocatalytic, and photoelectrochemical studies and proposed mechanism further support the enhanced visible light photocatalytic activities of the m-CeO₂. This study confirmed that defect-induced band gap engineered m-CeO₂ could be used effectively as photocatalyst and photoelectrodes owing to their enhanced visible light photocatalytic activities.