Electrocatalytic oxygen reduction on silver nanoparticle/multi-walled carbon nanotube modified glassy carbon electrodes in alkaline solution

The electrochemical reduction of oxygen was studied on Ag nanoparticle/multi-walled carbon nanotube (AgNP/MWCNT) nanocomposites in alkaline solution employing the rotating disk electrode (RDE) method. The composite material was prepared by sputter deposition of Ag catalyst on the surface of MWCNTs. The surface morphology of the AgNP/MWCNT composites was examined by scanning electron microscopy (SEM). The SEM images show that there is a wide size distribution of Ag particles on MWCNTs. The RDE results reveal a high electrocatalytic activity of the AgNP/MWCNT nanocomposites towards the oxygen reduction reaction (ORR). On these catalysts the ORR proceeds by a four-electron pathway. The AgNP/MWCNT composite is a good catalyst for peroxide reduction. The results obtained are important for the development of Ag-based catalysts for alkaline membrane fuel cells.

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► AgNP/MWCNT nanocomposites were prepared by magnetron sputtering.
► Oxygen reduction was studied on the AgNP/MWCNT catalysts in alkaline media.
► The electrocatalytic activity of a AgNP/MWCNT catalyst was higher than that of bulk Ag.
► The Tafel behaviour of oxygen reduction was similar for AgNP/MWCNT and bulk Ag.