物理化学学报 >> 2013, Vol. 29 >> Issue (10): 2232-2238.doi: 10.3866/PKU.WHXB201308291

催化和表面科学 上一篇    下一篇

Cu掺杂TiO2纳米管可见光催化矿化甲苯

赵伟荣, 奚海萍, 廖求文   

  1. 浙江大学环境工程系, 杭州 310058
  • 收稿日期:2013-05-21 修回日期:2013-08-27 发布日期:2013-09-26
  • 通讯作者: 赵伟荣 E-mail:weirong@mail.hz.zj.cn
  • 基金资助:

    国家自然科学基金(51178412, 51278456)及浙江省教育厅科研项目(Z201122663)资助

Cu-Doped Titania Nanotubes for Visible-Light Photocatalytic Mineralization of Toluene

ZHAO Wei-Rong, XI Hai-Ping, LIAO Qiu-Wen   

  1. Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, P. R. China
  • Received:2013-05-21 Revised:2013-08-27 Published:2013-09-26
  • Contact: ZHAO Wei-Rong E-mail:weirong@mail.hz.zj.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51178412, 51278456) and Zhejiang Provincial Education Department Scientific Research Projects, China (Z201122663).

摘要:

采用低温水热法制备氢钛酸管, 通过吸附-煅烧法制备Cu掺杂TiO2纳米管(Cu-TNT)催化剂. 利用X射线衍射(XRD)、电感耦合等离子体-原子发射光谱(ICP-AES)、X射线光电子能谱(XPS)、透射电镜(TEM)、紫外-可见漫反射光谱(UV-Vis-DRS)和电化学测试手段对样品进行表征, 并进行平面波赝势密度泛函理论(DFT)计算. 结果表明, 样品中Cu/Ti原子比接近理论值, Cu掺杂进入TiO2晶格内部, 诱发催化剂可见光活性. 掺Cu后,Cu 3d轨道和O 2p轨道杂化形成价带顶, 价带负向偏移, 样品禁带宽度减小为2.50-2.91 eV, 具有可见光响应.以甲苯为模型污染物研究催化剂对挥发性有机化合物(VOCs)的催化去除和矿化效果. 未掺杂的TNT可见光催化活性较差; Cu掺杂量超过0.1%(Cu/Ti原子比)时, 样品催化活性也减弱; Cu掺杂量为0.1%的催化剂具有最佳可见光催化氧化能力, 7 h内甲苯的去除率达77%, 甲苯的矿化率达59%.

关键词: 水热法, 吸附-煅烧法, 电化学, 密度泛函理论, 挥发性有机化合物, 二氧化碳

Abstract:

Based on hydrogen titanate nanotubes prepared by a low-temperature hydrothermal technique, Cu-doped titania nanotube (Cu-TNT) catalysts were prepared using absorption-calcination methods. They were characterized by X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and electrochemical techniques. Density functional theory (DFT) was used to calculate the nanotube band structure and density of states. Cu/Ti atomic ratios in the synthesized powders were very close to the nominal values, and the Cu-doped TiO2 lattice exhibited improved visible-light absorption. This was because the valence band, formed by hybridization of O 2p states with Cu 3d states, was negatively shifted. Thus, the band gap was reduced to 2.50-2.91 eV and the samples exhibited visible-light responses. Toluene was chosen as a model pollutant to evaluate the removal capacity and the CO2 mineralization rate of volatile organic compounds under visible light. Pure TNT displayed poor visible-light activity, and the activities of samples with >0.1% Cu doping were also weak. Samples doped with 0.1% Cu exhibited optimumvisible-light photocatalytic oxidation activity, with a 77%toluene degradation efficiency and a 59%mineralization rate in 7 h.

Key words: Hydrothermal method, Impregnation-calcination method, Electrochemical, Density functional theory, Volatile organic compounds, CO2

MSC2000: 

  • O643