Atomic Layer Deposition of Gold Nanoparticles with Controlled Size and Distribution on Titania Support

Graphical Ultrafine Au nanoparticles with a narrowly distributed size were synthesized on TiO 2 by ALD using Me 2 Au(acac) and ozone as the precursor reactants. Nano-sized gold particles have shown unique merits in the field of catalysis, sensing and imaging, whereas their controllable synthesis with sub-nanometer size and narrow distribution on a support still remains a challenge. Herein, we developed a facile and controllable process of atomic layer deposition (ALD) using dimethyl(acetylacetonate)gold (Me 2 Au(acac)) and ozone as the precursor reactants to directly synthesize ultrafine Au nanoparticles on titania support. The size of Au nanoparticles could be precisely controlled via the modulation of depositing temperature and the counter reactant. Additionally, the dispersion of Au nanoparticles on the support is decreased by pre-calcining TiO 2 in air, which is due to the decreased surface hydroxyls concentration on support, leading to less adsorption sites of gold precursor. Moreover, we demonstrated that Au nanoparticles prepared by this method on TiO 2 could function as an effective co-catalyst for photocatalytic hydrogen evolution reaction.