Novel Ag2ZnGeO4 photocatalyst for dye degradation under visible light irradiation
Novel Ag2ZnGeO4 photocatalyst for dye degradation under visible light irradiation
复制标题
DOI：
10.1016/j.apcata.2007.09.033
复制
发表时间：
2008-01-01
影响因子：
5.5
通讯作者：
Ye, Jinhua
中科院分区：
文献类型：
--
作者：
Li, Xiukai;Ouyang, Shuxin;Ye, Jinhua
我们报道了一种具有方英石相关结构的多金属氧化物Ag2ZnGeO4，作为可见光敏感光催化剂（例如2.29 eV）用于染料降解。通过 XRD、紫外可见漫反射光谱和 SEM 等技术检查了样品的物理特性。 Ag2ZnGeO4 的光催化活性通过罗丹明 B (RhB) 和 Orange II 在水相中的光降解得到证实。可见光（λ > 420 nm）照射360 min后，RhB和Orange II的转化率分别达到100%和69.2%。通过基于密度函数理论（DFY）的能带结构计算研究了Ag2ZnGeO4的电子结构。结果表明，杂化的Ag 4d(10) 和O 2P(6) 轨道形成了Ag2ZnGeO4 的价带顶，这导致与Na2ZnGeO4 母体样品相比带隙窄得多。我们认为 Ag2ZnGeO4 的特定方英石结构有利于光生载流子的迁移率，这对观察到的染料降解光催化活性有积极贡献。 (c) 2007 Elsevier B.V. 保留所有权利。
We report a multiple-metal oxide Ag2ZnGeO4 With cristobalite-related structure as a visible light-sensitive photocatalyst (Eg 2.29 eV) for dye degradation. The physical characteristics of the samples were examined by techniques such as XRD, UV-vis diffuse reflectance spectroscopy and SEM. The photocatalytic activity of Ag2ZnGeO4 was confirmed by Rhodamine B (RhB) and Orange II photodegradation in aqueous phase. After 360 min of visible light (lambda > 420 nm) irradiation, the conversions of RhB and Orange II reached 100% and 69.2%, respectively. The electronic structure of Ag2ZnGeO4 was investigated by band structure calculation based on the density function theory (DFY). Results revealed that the hybridized Ag 4d(10) and O 2P(6) orbitals form the valence band top of Ag2ZnGeO4, which leads to a much narrowed band gap as compared with that of the Na2ZnGeO4 parent sample. We propose that the specific cristobalite structure of Ag2ZnGeO4 favors the mobility of photo-generated carriers, and that this contributes positively to the observed photocatalytic activity for dye degradation. (c) 2007 Elsevier B.V. All rights reserved.