Controlled Deposition of Gold Nanoparticles on Titania Support

In our research, the commercial TiO2 (Degussa P25) was modified with gold nanoparticles (Au NPs) by reduction reaction with trisodium citrate. A remarkable influence of pH on particle size, size distribution and dispersion of Au on TiO2 support was observed. The size of Au NPs on TiO2 surface decreased with increase in the pH of the precursor solution. The increase of pH involved a transformation of [AuCl4]- complexes to [Au(OH)xCl(4-x)]- complexes which could induce strong Au-TiO2 interactions, resulted in uniform dispersion of Au NPs. Complete citrate reduction of Au precursor facilitated the deposition of stable Au NPs with small particle size and narrow size distribution.