Platinum nanoparticles supported on nitrobenzene-functionalised graphene nanosheets as electrocatalysts for oxygen reduction reaction in alkaline media

•Nitrobenzene (NB)-modified graphene nanosheets were used as a support for PtNPs.•Oxygen electroreduction on the Pt-NB/G catalyst was studied in alkaline solution.•Specific activity of Pt-NB/G for ORR was close to that of 20 wt% Pt/C catalyst.•Long-term durability test showed high stability of the Pt-NB/G catalyst in 0.1 M KOH.

A systematic study on the electrocatalytic properties of Pt nanoparticles supported on nitrobenzene-modified graphene (Pt-NB/G) as catalyst for oxygen reduction reaction (ORR) in alkaline solution was performed. Graphene nanosheets were spontaneously grafted with nitrophenyl groups using 4-nitrobenzenediazonium salt. The electrocatalytic activity towards the ORR and stability of the prepared catalysts in 0.1 M KOH solution have been studied and compared with that of the commercial Pt/C catalyst. The results obtained show that the NB-modified graphene nanosheets can be good Pt catalyst support with high stability and excellent electrocatalytic properties. The specific activity of Pt-NB/G for O2 reduction was 0.184 mA cm−2, which is very close to that obtained for commercial 20 wt% Pt/C catalyst (0.214 mA cm−2) at 0.9 V vs. RHE. The Pt-NB/G hybrid material promotes a four-electron reduction of oxygen and can be used as a promising cathode catalyst in alkaline fuel cells.

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