Adsorption properties of single gold, nickel and platinum nanoparticles deposited on the silicon surface

Abstract

Gold, nickel and platinum nanoparticles were synthesized by impregnating the monocrystalline silicon surface with precursors (an aqueous solution of the corresponding salt). The morphology of formed nanostructured coatings has been studied, the electronic structure and adsorption properties of synthesized nanoparticles with respect to H2, O2, and H2O have been determined. It was found that oxidized nickel nanoparticles are reduced by molecular hydrogen, and unalloyed platinum nanoparticles are oxidized by molecular oxygen already at room temperature, which is not observed for particles deposited in a similar way on highly oriented pyrolytic graphite. We also found that the formation of water molecules on gold nanoparticles in interaction with H2 and O2 proceeds in two stages, unlike the three-stage process (sequential exposure in H2, O2, H2) which is characteristic of nanoparticles deposited on graphite. Differences in the adsorption properties of nanoparticles of the same type deposited on graphite and silicon are associated with the adsorption of a significant amount of test gases on the latter.