Electrocatalytic reduction of oxygen on bimetallic copper–gold nanoparticles–multiwalled carbon nanotube modified glassy carbon electrode in alkaline solution

Multiwalled carbon nanotubes (MWCNTs) were functionalized with acid treatment and thereafter gold–copper nanoparticles were electrodeposited on the MWCNTs by applying several repetitive scans, thus forming a Cu–Au–MWCNT/GCE interface. The electrochemical reduction of oxygen was studied on this modified electrode in 0.1 M NaOH solution. The electrocatalytic activity on the Cu–Au–MWCNT/GCE showed a tendency towards the O2 reduction. The peak potential of O2 reduction on the Cu–Au–MWCNT/GCE shifted ca. 70 mV higher positive potentials as compared to that of a polished glassy carbon electrode. A significant current enhancement was obtained on the Cu–Au–MWCNT/GCE compared to that of bare GCE, MWCNT/GCE, Cu–MWCNT/GCE and Au–MWCNT/GCE. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed in order to investigate the surface morphology and elemental composition of the modified electrode, respectively.