The gold ion modified TiO 2 was prepared by means of sol\|gel whereas gold deposited TiO\-2 was prepared by means of photo\|reduction. The physical properties were influenced significantly by the presence of gold ion or gold. The enhanced photo\|activity of gold modified TiO\-2 was quantified in terms of methylene blue degradation. The presence of gold ion in TiO\-2 lattices or gold on TiO\-2 surface enhanced their photo\|activity. The optimum molar content of gold ion doping and gold deposition all was 0.5%. The first\|order rates constants of gold modified TiO\-2 was more than that of pure TiO\-2, and decreased by increasing the content of gold ion and gold when their contents were more than 0.5%. Gold ion doped in TiO\-2 lattices was more effective to enhance the photo\|activity than gold on TiO\-2 surface. Moreover, the relationship between physical properties, chemical properties and photo\|activity has been discussed.
LI Fang-baiGU Guo-bangHUANG Guo-fengLI Xin-junWAN Hong-fu
