Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (10): 2232-2238.doi: 10.3866/PKU.WHXB201308291

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

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).

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