可见光响应型CuO/BiVO_4的光催化活性研究  

The photocatalytic activity of CuO/BiVO_4 composites under visible light

作　　者：尹盛[1] 曹娟[1] 许晖[1,2] 李华明[1] 吴春笃[2] 徐远国[1] 

机构地区：[1]江苏大学化学化工学院,江苏镇江212013 [2]江苏大学环境学院,江苏镇江212013

出　　处：《环境污染与防治》2010年第4期20-24,共5页Environmental Pollution & Control

基　　金：国家自然科学基金资助项目(No.20876071;No.20676057;No.20871061);江苏省普通高校研究生科研创新计划项目(No.CX08B-142Z)

摘　　要：采用浸渍法制备了CuO/BiVO4光催化剂,通过X射线衍射(XRD)、热重/差示扫描量热(TG/DSC)和傅立叶红外光谱(FTIR)对其进行了表征,并在可见光照射下考察了其光催化氧化亚甲基蓝(MB)的动力学特性。结果表明,Cu的掺杂并未改变BiVO4的晶型结构;Cu(NO3)2/BiVO4在热处理(30～300℃)过程中,NO3-已经完全分解,Cu最终以CuO的形式存在于CuO/BiVO4光催化剂体系中;掺杂不同量Cu的CuO/BiVO4中的Cu2+/Bi+(摩尔比)实测值与理论值相近,该系列光催化剂的合成过程具有较高的可信度;在可见光照射下,CuO/BiVO4光催化降解MB反应符合表观一级反应动力学特征;当Cu2+/Bi+为0.050时,反应动力学速率常数(k)达到最高值(0.4334h-1),此时的k比单体BiVO4作用下的提高了1.04倍;由于异质结的存在,CuO/BiVO4与单体BiVO4相比,电子和空穴的利用率大大增加,使得CuO/BiVO4的光催化活性较单体BiVO4有了大幅度提高。The CuO/BiVO4 photocatalyst was synthesized by dipping method, and then characterized by X-ray diffraction （XRD）, TG/DSC and FTIR. The kinetics characteristic of methylene blue （MB） degradation by CuO/ BiVO4 under visible light irradiation was also investigated. The results indicted that the presence of CuO did not change the crystallinity of the host BiVO4. The FTIR and TG/DSC analysis showed NO3^- was completely decomposed and CuO generated through the thermal treatment of the Cu（NO3）2/BiVO4 mixture under 300 ℃. The process of CuO/BiVO4 synthesis was proved to be highly reliable, for the measured Cu^2＋/Bi^＋ of different Cu contained CuO/BiVO4 agreed well with theory Cu^2＋/Bi^＋ values. The photocatalytic degradation of MB using CuO/BiVO4 catalysts followed the first-order reaction kinetic model. The rate constant k, which increased with increasing CuO content, could reach the highest of 0. 433 4 h^-1 when Cu^2＋/Bi^＋ was 0. 050, and the reaction rate was 1.04 times superior to that of single BiVO4. The photocatalytic activity of CuO/BiVO4 was greatly improved for the existence of heterojunction enhanced the utilization efficiency of electrons and holes.

关 键 词：CuO/BiVO4 光催化 可见光 亚甲基蓝 

分 类 号：X703[环境科学与工程—环境工程]