Covalent Hybridization of Thiolated Graphene Sheet and Platinum Nanoparticles for Electrocatalytic Oxygen Reduction Reaction

A covalently bonded thiolated graphene sheet-supported platinum electrocatalyst (GOS–Pt) has synthesized for electrochemical oxygen reduction reaction (ORR) in neutral media. The catalyst's structural features are characterized by transmission electron microscopy (TEM), energy dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). Its activity towards the ORR has investigated by using cyclic voltammetry (CV), rotating disk electrode (RDE), and rotating ring disk electrode (RRDE) in 0.1 mol l⁻¹ phosphate buffer solution (PBS) at pH 7, which is also used to assess the catalyst's kinetic parameters. On a glassy carbon electrode (GCE), the catalyst shows a significant catalytic activity, with its electrocatalysis of O₂ reduction occurring via four-electron transfer reduction to H₂O with minimal generation of H₂O₂.