光催化剂Bi_(1-x)Gd_xVO_4的制备和表征及其光催化分解水  

Preparation and Characterization of Bi_(1-x)Gd_xVO_4 Photocatalyst and Its Application to Water Splitting

作　　者：王其召[1,2] 蒋丽[1] 刘恢[1] 袁坚[1] 陈铭夏[1] 施建伟[1] 上官文峰[1] 

机构地区：[1]上海交通大学燃烧与环境技术研究中心,上海200240 [2]西北师范大学化学化工学院,兰州730070

出　　处：《物理化学学报》2009年第8期1703-1707,共5页Acta Physico-Chimica Sinica

基　　金：国家重点基础研究发展计划(973)项目(2009CB220000)资助~~

摘　　要：通过高温固相法合成了不同组分的光催化剂Bi1-xGdxVO4(x=0,0.1,0.2,0.3,0.5,0.7,0.9,1.0),并用X射线衍射(XRD)、紫外-可见漫反射光谱(DRS)、比表面积分析(BET)、扫描电子显微镜(SEM)对催化剂Bi1-xGdxVO4进行了表征和分析.XRD结果表明,在Bi1-xGdxVO4中存在两种结构,当0.3≤x≤1.0时,Bi1-xGdxVO4为四方晶系硅酸锆型结构;当x=0时,为单斜晶系白钨矿结构BiVO4;当0<x<0.3时,Bi1-xGdxVO4为单斜BiVO4和四方Bi1-xGdxVO4的混合物.负载了0.3%(w)Pt的Bi1-xGdxVO4在紫外光照射下能够分解纯水产生氢气,其中Bi0.5Gd0.5VO4的催化活性最好.Bi0.5Gd0.5VO4负载了助催化剂Pt、RuO2、Pt/Cr2O3、Rh/Cr2O3、Rh或Au后,在紫外光下可以光催化分解水生成氢气和氧气.其中负载RuO2、Pt/Cr2O3、Rh/Cr2O3能够完全分解水,负载Rh/Cr2O3时具有最好的光催化活性,并且可见光分解水的活性也得到了验证.在紫外光照射下,负载Rh/Cr2O3的Bi0.5Gd0.5VO4催化剂分解水产生氢气和氧气的速率分别为48.22和24.13μmol·h-1.研究结果表明,形成固溶体来调节价带和导带,是获得可见光响应光催化剂的一种可行的方法.Bi1-xGdxVO4（x=0, 0.1, 0.2, 0.3, 0.5, 0.7, 0.9, 1.0） solid oxide solutions were synthesized by a solid state reaction at high temperature and characterized by X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy （DRS）, BET surface area and scanning electron microscopy （SEM）. XRD analysis of the Bi1-xGdxVO4 system showed the existence of two structures. For 0.3 ≤x ≤1.0, the structure was of zircon-tetragonal type while the structure was scheelite-monoclinic when x=0. For 0.1≤x≤0.3, tetragonal and monoclinic structures were observed. Bi1-xGdxVO4 can split water into hydrogen when loaded with 0.3% （w） Pt. Furthermore, while Bi0.5Gd0.5VO4 was found to act as a photocatalyst for overall water splitting under UV light when loaded with RuO2, Pt/Cr2O3 and Rh/Cr2O3 we found that the photocatalyst loaded with Rh/Cr2O3 had the best photocatalytic property. The amounts of hydrogen and oxygen produced were about 48.22 and 24.13 μmol·h^-1 under UV light irradiation, respectively. The photocatalytic activity for water splitting under visible light was also examined. This study indicated that the formation of a solid solution was a feasible method to adjust the conduction band and valence band to obtain a visible-light-driven photocatalyst.

关 键 词：光催化 Bi1-xGdxVO4 可见光 水的分解 固溶体 

分 类 号：O643.36[理学—物理化学]