Au-CeO2 nanoporous films/carbon nanotubes composites prepared by magnetron sputtering

► Carbon exhibits a significant influence on morphology and stoichiometry of the sputtered CeO2 thin films. ► Au-CeO2 catalyst films prepared by simultaneous magnetron sputtering exhibit high concentration of Au+ and Au3+ ions. ► Distribution of gold oxidation states on the surface of the catalyst as well as surface roughness were found to be depending on the film thickness.