Magnetic ZnFe2O4鈥揅3N4 Hybrid for Photocatalytic Degradation of Aqueous Organic Pollutants by Visible Light

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• 作者：Yunjin Yao ; Yunmu Cai ; Fang Lu ; Jiacheng Qin ; Fengyu Wei ; Chuan Xu ; Shaobin Wang
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：November 5, 2014
• 年：2014
• 卷：53
• 期：44
• 页码：17294-17302
• 全文大小：582K
• ISSN：1520-5045

文摘

Magnetic ZnFe₂O₄鈥揅₃N₄ hybrids were successfully synthesized through a simple reflux treatment of ZnFe₂O₄ nanoparticles (NPs) (ca. 19.1 nm) with graphitic C₃N₄ sheets in methanol at 90 掳C, and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and UV鈥搗is diffuse reflectance spectroscopy. Also, the catalytic activities of heterogeneous ZnFe₂O₄鈥揅₃N₄ catalysts were evaluated in photo-Fenton discoloration toward Orange II using H₂O₂ as an oxidant under visible light (位 > 420 nm) irradiation. The reaction kinetics, degradation mechanism, and catalyst stability, as well as the roles of ZnFe₂O₄ and C₃N₄ in photoreaction, were comprehensively studied. It was found that the ZnFe₂O₄鈥揅₃N₄ photocatalysts presented remarkable catalytic ability at neutral conditions, which is a great advantage over the traditional Fenton system (Fe²⁺/H₂O₂). The ZnFe₂O₄鈥揅₃N₄ hybrid (mass ratio of ZnFe₂O₄/g-C₃N₄ = 2:3) exhibits the highest degradation rate of 0.012 min^鈥?, which is nearly 2.4 times higher than that of the simple mixture of g-C₃N₄ and ZnFe₂O₄ NPs. g-C₃N₄ acted as not only a p-conjugated material for the heterojunction formation with ZnFe₂O₄, but also a catalyst for the decomposition of H₂O₂ to 路OH radicals. The heterogeneous ZnFe₂O₄鈥揅₃N₄ hybrid exhibited stable performance without losing activity after five successive runs, showing a promising application for the photo-oxidative degradation of organic contaminants.