Research on Chemical Intermediates

, Volume 39, Issue 4, pp 1633–1644

Effect of Ag doping concentration on the electronic and optical properties of anatase TiO2: a DFT-based theoretical study

  • Matiullah Khan
  • Junna Xu
  • Ning Chen
  • Wenbin Cao
  • Asadullah
  • Zahid Usman
  • D. F. Khan
Article

DOI: 10.1007/s11164-012-0897-y

Cite this article as:
Khan, M., Xu, J., Chen, N. et al. Res Chem Intermed (2013) 39: 1633. doi:10.1007/s11164-012-0897-y

Abstract

The electronic and optical properties of pure and Ag-doped anatase TiO2 have been calculated by spin-polarized density functional theory. Ag-doped TiO2 with different Ag doping concentrations ranging from 2.08 to 8.33 % was investigated, and the electronic and optical properties evaluated. Substitutional Ag doped at Ti sites introduced Ag 4d states just above the valence-band maximum, which may help in shifting visible-light excited electrons to the conduction band. Our results show that increasing the doping concentration will enhance visible-light absorption up to Ag doping concentration of 6.25 %; however, further increase of the doping concentration leads to a decrease in visible-light absorption. These results indicate the possibility of tailoring the band gap and optical absorption of TiO2 doped with Ag by varying the doping concentration. The enhanced visible-light absorption for Ag-doped TiO2 with doping concentration of 6.25 % may be due to the existence of widely distributed Ag 4d states above the valence-band maximum and the optimal doping concentration. Ag doping shifted the absorption edge of TiO2 towards visible light, consistent with recent experimental results. Our calculation results provide a reasonable explanation for the experimental findings.

Keywords

Ag-doped TiO2DFTOptimal doping

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Matiullah Khan
    • 1
    • 4
  • Junna Xu
    • 1
  • Ning Chen
    • 1
  • Wenbin Cao
    • 1
  • Asadullah
    • 2
  • Zahid Usman
    • 3
  • D. F. Khan
    • 2
  1. 1.Department of Inorganic Nonmetallic MaterialsSchool of Materials Science and Engineering, University of Science and Technology Beijing (USTB)BeijingChina
  2. 2.School of Materials Science and EngineeringUniversity of Science and Technology Beijing (USTB)BeijingChina
  3. 3.School of Material Science and Engineering, Beijing Institute of TechnologyBeijingChina
  4. 4.Physics DepartmentUniversity of Science and Technology BannuBannuPakistan