Enhanced photo--catalytic activity of gold ion and gold modified

The gold ion modified TiO2 was prepared by means of sol-gel whereas gold deposited TiO2 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 TiO2 was quantified in terms of methylene blue degradation. The presence of gold ion in TiO2 lattices or gold on TiO2 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 TiO2 was more than that of pure TiO2, and decreased by increasing the content of gold ion and gold when their contents were more than 0.5%. Gold ion doped in TiO2 lattices was more effective to enhance the photo-activity than gold on TiO2 surface. Moreover, the relationship between physical properties, chemical properties and photo-activity has been discussed.