Journal of Inorganic Materials

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Doping Mechanism and Visible-light Photocatalytic Activity of S-doped TiO2 Nano Powders

ZHOU Wu-Yi1, CAO Qing-Yun2, TANG Shao-Qiu3, LIU Ying-Ju1   

  1. 1. Department of Applied Chemistry, College of Science, South-China Agricultural University, Guangzhou 510642, China;
    2.
    Center of Testing, College of Animal Science, South-China Agricultural University, Guangzhou 510642, China;
    3.
    College of Materials Science and Engineering, Hunan University, Changsha 410082, China

  • Received:2005-08-12 Revised:2005-11-18 Published:2006-07-20 Online:2006-07-20

Abstract:

S-doped TiO2 nanopowders were prepared by a sol-gel method with acid as the catalyst. The results of photocatalytic degradation methylene blue demonstrated that the doped TiO2 exhibited the highest photocatalytic activity when the mole ratio of thiourea and tetrabutyltitanate[Ti(OC4H9)4] was 3.5 and the doped TiO2 was calcined at 500℃ for 2h. The results from the X-ray diffraction (XRD), diffusion reflectance spectra (DRS) and X ray photoelectron spectroscopy (XPS) showed that sulfur doping controlled the increasing of nano TiO2 and restrained
the transformation from anatase to rutile. S2- was
oxidezed to S4+ during
the thermal treatment. The trance of sulfur ions (S4+)
substitued partially
for the lattice titanium ions (Ti4+), which resulted in
the localized crystal
deformation of TiO2 and the bandgap between valence band
and conduction
band narrowed, and the absorption light transferred to
visible light region.

Key words: nano TiO2, sulfur doping, mechanism, visible light catalytic degradation

CLC Number: