Enhanced electrocatalytic performance toward oxygen reduction in an alkaline medium by anchoring cobalt tetraferrocenylphthalocyanine onto graphene

A novel non-noble-metal electrocatalyst, abbreviated as CoFcPc/PSS-Gr, was fabricated through a solvothermally assisted pi-pi assembling approach by anchoring cobalt tetraferrocenylphthalocyanine (CoFcPc) onto poly(sodium-p-styrenesulfonate) modified graphene (PSS-Gr). The as-prepared hybrid was characterized by scanning electron microscopy, transmission electron microscopy, UV-Vis absorption spectroscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry, rotating disk electrode, and rotating ring-disk electrode measurements were employed to investigate the kinetics and mechanism of the ORR on the CoFcPc/PSS-Gr electrode. Besides, the chronoamperometric measurements were utilized to evaluate the stability of the CoFcPc/PSS-Gr composite in an alkaline solution. The obtained results demonstrated that CoFcPc supported on PSS-Gr showed good tolerance to methanol crossover, high kinetic current density (9.51 mA cm(-2)), high stability (84.6 % after 10,000 s), and an almost four-electron transfer process in an alkaline medium.