Photocatalytic Properties of the Ag-Doped TiO2 Prepared by Sol-Gel Process/Photodeposition

졸-겔공정/광증착법을 이용한 Ag-Doped TiO2 합성 및 광촉매 특성

  • Kim, Byeong-Min (Department of Materials Science and Engineering, University of Seoul) ;
  • Kim, Jung-Sik (Department of Materials Science and Engineering, University of Seoul)
  • 김병민 (서울시립대학교 신소재공학과) ;
  • 김정식 (서울시립대학교 신소재공학과)
  • Received : 2015.12.18
  • Accepted : 2016.01.08
  • Published : 2016.02.27


$TiO_2$ nanoparticles were synthesized by a sol-gel process using titanium tetra isopropoxide as a precursor at room temperature. Ag-doped $TiO_2$ nanoparticles were prepared by photoreduction of $AgNO_3$ on $TiO_2$ under UV light irradiation and calcinated at $400^{\circ}C$. Ag-doped $TiO_2$ nanoparticles were characterized for their structural and morphological properties by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The photocatalytic properties of the $TiO_2$ and Ag-doped $TiO_2$ nanoparticles were evaluated according to the degree of photocatalytic degradation of gaseous benzene under UV and visible light irradiation. To estimate the rate of photolysis under UV (${\lambda}=365nm$) and visible (${\lambda}{\geq}410nm$) light, the residual concentration of benzene was monitored by gas chromatography (GC). Both undoped/doped nanoparticles showed about 80 % of photolysis of benzene under UV light. However, under visible light irradiation Ag-doped $TiO_2$ nanoparticles exhibited a photocatalytic reaction toward the photodegradation of benzene more efficient than that of bare $TiO_2$. The enhanced photocatalytic reaction of Ag-doped $TiO_2$ nanoparticles is attributed to the decrease in the activation energy and to the existence of Ag in the $TiO_2$ host lattice, which increases the absorption capacity in the visible region by acting as an electron trapper and promotes charge separation of the photoinduced electrons ($e^-$) and holes ($h^+$). The use of Ag-doped $TiO_2$ nanoparticles preserved the option of an environmentally benign photocatalytic reaction using visible light; These particles can be applicable to environmental cleaning applications.


Supported by : Ministry of Land, Infrastructure and Transport of Korean government


  1. M. Anpo and M. Takeuchi, J. Catal., 216, 505 (2003).
  2. A. Fujishima and K. Honda, Bull. Chem. Soc. Jpn., 44, 1148 (1971).
  3. A. Fujishima and K. Honda, Nature, 238, 37 (1972).
  4. S. D. Mo and L. B. Lin, J. Phys. Chem. Solid., 55, 1309 (1994).
  5. K. Vinodgopal, D. E. Wynkoop and P. V. Kamat, Environ. Sci. Tech., 30, 1660 (1996).
  6. V. Vamathevan, R. Amal, D. Beydoun, G. Low and S. McEvoy, J. Photochem. Photobiol. Chem., 148, 233 (2002).
  7. J. M. Herrmann, J. Disdier and P. Pichat, J. Phys. Chem., 90, 6028 (1986).
  8. K. Shiba, H. Hinode and M. Wakihara, React. Kinet. Catal. Lett., 64, 281 (1998).
  9. G. Fu, P. S. Vary and C. T. Lin, J. Phys. Chem. B, 109, 8889 (2005).
  10. N. Nino-Martinez, G. A. Martinez-Castanon, A. Aragon-Pina, F. Martinez-Gutierrez, J. R. Martinez-Mendoza and Facundo Ruiz, Nanotechnology, 19, 065711 (2008).
  11. A. L. Patterson, Phys. Rev., 56, 978 (1939).
  12. R. A. Spurr and H. Myers, Anal. Chem., 29, 760 (1957).
  13. A. Peled and N. Mirchin, Photo-Excited Process, Diagnostics and Applications (PEPDA), Aaron Peled ed., p.251, Kluwer Academic Publishers, Netherlands (2003).
  14. C. Crisafulli, S. Scire, S. Giuffrida, G. Ventimiglia and R. Lo Nigro, Appl. Catal. Gen., 306, 51 (2006).
  15. S. Giuffrida, G. G. Conderelli, L. L. Costanzo, G. Ventimiglia, R. Lo Nigro, M. Favazza, E. Votrico, C. Bongiorno and I. L. Fragala, J. Nanopart. Res., 9, 611 (2007).
  16. S. Scire, C. Crisafulli, S. Giuffrida, G. Ventimiglia, C. Bongiorno and C. Spinella, J. Mol. Catal. Chem., 333, 100 (2010).
  17. J. C. Scaiano, P. Billone, C. M. Gonzalez, L. Marett, M. L. Marin, K. L. McGilvray and N. Yuan, Pure. Appl. Chem., 81, 635 (2009).
  18. A. L. Linsebigler, G. Lu and J. T. Yates, Chem. Rev., 95, 735 (1995).
  19. D. Yang, S. E. Park, J. K. Lee and S. W. Lee, J. Cryst. Growth, 311, 508 (2009).
  20. C. Suwanchawalit, S. Wongnawa, P. Sriprang and P. Meanha, Ceram. Int., 38, 5201 (2012).
  21. D. Zhang, X. Song, R. Zhang, M. Zhang and F. Liu, Eur. J. Inorg. Chem., 2005, 1643 (2005).