Adsorption Properties of the Film Formed by Gold and Copper Nanoparticles on Graphite

Resumo

Some physicochemical properties of homogeneous and heterogeneous films formed by Au and Cu nanoparticles on graphite are studied by scanning tunneling microscopy and spectroscopy. It is found that the nanoparticles have a shape close to spherical with a diameter of 3‒6 nm, the gold particles do not contain impurities, and the copper particles can be coated with oxide. The adsorption properties of nanostructured coatings with respect to hydrogen, carbon oxide, and oxygen are determined. Copper oxide is reduced by carbon oxide and hydrogen, but the latter is also adsorbed onto oxide-free copper particles and gold. Exposure to oxygen results in the reformation of the oxide on copper. The possibility of rearranging the electronic structure of copper nanoparticles during hydrogen adsorption is confirmed by the results of quantum chemical simulation.