Gold nanoparticles supported on titania for the reduction of p-nitrophenol

Supported gold nanoparticles on titania have been prepared using the deposition-precipitation method at several pH levels. The effects of pH on gold loading, particle size and particle size distribution are studied, both below and above the isoelectric point of TiO2. The effects of adjusting the pH before and after the addition of the support to gold chloride solution are also investigated. Gold particles with diameters of less than 10 nm have been obtained. The results reveal dependence of the gold particle size, and loading and distribution on the pH. The supported Au nanoparticles have been tested for the reduction of p-nitrophenol and found to exhibit particle size-dependent behavior. The highest rate constant of 16.9 × 10 s has been obtained for the Au particles size between 4 and 5 nm.