Electrochemical oxygen reduction behaviour of platinum nanoparticles supported on multi-walled carbon nanotube/titanium dioxide composites

Pt nanoparticle-titanium dioxide/multi-walled carbon nanotube (Pt-TiO₂/MWCNT) materials were synthesised by combining chemical vapour deposition (CVD), atomic layer deposition (ALD) and magnetron sputtering techniques. These composite materials were employed as electrocatalysts for oxygen reduction reaction (ORR). The surface morphology of the prepared catalysts as well as their supports was examined by scanning electron microscopy (SEM). The SEM images revealed the preferential growth of aligned MWCNTs. The surface composition of Pt-TiO₂/MWCNT catalysts was characterised using X-ray photoelectron spectroscopy (XPS). Their electrocatalytic properties toward the ORR were investigated in acid and alkaline media using the rotating disk electrode (RDE) technique. The ORR activity of Pt-TiO₂/MWCNT was compared with that of commercial Pt/C catalyst and bulk Pt.