银粒子修饰下的介孔二氧化钛的制备及其光催化性能的研究

doi:10.15541/jim20150535

摘要/Abstract

摘要：

利用光还原的方法制备一系列不同银含量的改性介孔二氧化钛的颗粒。采用X射线粉末衍射(XRD)、透射电子显微镜(TEM)、紫外一可见漫反射谱(DRS)和X射线能谱仪(EDX)等技术手段对制备的样品进行了表征。结果表明, 银纳米粒子被牢牢固定在二氧化钛表面, 并在银和二氧化钛界面形成肖特基势垒用以提高电子-空穴的分离。而从紫外可见漫反射光谱中看出, 银二氧化钛样品与未改性的二氧化钛样品相比显示出更高的红移。以亚甲基蓝(MB)为光降解模型, 银改性二氧化钛表现出较高的活性。

关键词: 银纳米粒子, 介孔二氧化钛, 光催化, 光致还原

Abstract:

A series of Ag-modified mesoporous titania (TiO₂) particles with various silver contents were prepared by photoreduction. The prepared Ag-TiO₂samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive X-ray spectrometry (EDX) and UV-visible diffuse reflectance spectroscopic (DRS) techniques. The visible light photocatalytic property was demonstrated for photodegradation of methylene blue (MB) solution. The results showed that Ag nanoparticles were firmly immobilized on the TiO₂ surface, which improved electron-hole separation by forming the Schottky barrier at the Ag-TiO₂ interface. The diffusion of reflectance UV-Vis spectra were also served as an indication that the Ag-TiO₂ samples displayed higher red shifts in comparison with un-modified TiO₂sample. Under visible light, the optimal photoactivity was obtained for the sample m-TiO₂-Ag- 2.0wt%. The TiO₂-Ag catalyst is likely to be used again for a number of times without any additional treatment.

Key words: silver nanoparticles, mesoporous titania, photodegraduation, photoreduction

中图分类号:

TQ174

王慧蕾, 刘孝恒. 银粒子修饰下的介孔二氧化钛的制备及其光催化性能的研究[J]. 无机材料学报, 2016, 31(5): 555-560.

WANG Hui-Lei1,2, LIU Xiao-Heng 1. Preparation of Silver Nanoparticle Loaded Mesoporous TiO₂ and Its Photocatalytic Property[J]. Journal of Inorganic Materials, 2016, 31(5): 555-560.

图/表 6

Fig. 1 XRD patterns of the m-TiO2 and Ag-modified TiO2 catalysts

Fig. 2 TEM micrographs of the prepared samples(a) TiO2-Ag-2.0wt%; (b) TiO2-Ag-24.0wt%; (c) TiO2-Ag-0.25wt%; (d) m-TiO2

Fig. 3 EDX spectra of the sample TiO2-Ag-2.0wt%

Fig. 4 Diffuse re?ectance absorption spectra of mesoporous TiO2 and Ag modiﬁed mesoporous TiO2

Fig. 5 Photocatalytic degradation curves of MB on samples and P25 under visible light

Fig. 6 Schematic illustration of the effect of Ag loadings on catalyst

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