THE SURFACE-CHEMISTRY OF HYBRID NANOMETER-SIZED PARTICLES .2. CHARACTERIZATION AND MICROSTRUCTURE OF AU CLUSTERS SUPPORTED ON TIO2

Nanometer sized Au/TiO2 particles were synthesized by irradiation of a HAuCl4 solution containing colloidal TiO2 with light of wavelength (l ambda) >330 nm. The absorption maximum attributed to the surface plasm on band of gold was observed at 530 nm, a red shift of about 10 nm fro m the position in aqueous solution, The particle size of Au/TiO2 deter mined by TEM was about 25 nm. The Au clusters are situated on the surf ace of TiO2 in terms of microcrystallite, which was confirmed by HRTEM , EDS, and XRD, A negative shift of binding energy in the Au 4f(7/2) f or gold cluster an the surface of TiO2 was found, and the electronic i nteraction between the metal and the support was discussed. (C) 1997 A cademic Press.