A new class of electroactive Fe- and P-functionalized graphene for oxygen reduction

Abstract

While metal and electronegative N-containing carbon has aroused great interest as an efficient catalyst towards the oxygen reduction reaction (ORR), no combination of metal with other heteroatom-containing carbon has received considerable attention. This has motivated us to explore the performance of carbon functionalized with metal and electropositive phosphorous. Herein, we present the first report on the synthesis of a new class of electroactive Fe- and P-functionalized graphene (GPFe) and its electrocatalytic properties in alkaline and acidic media. The introduction of Fe causes remarkable synergistic effects on P-doped reduced graphene oxide by increasing surface area, enhancing the P doping level due to the interaction between Fe and P and generating electrochemically active Fe–P species. N-oxides are known to be in-active for ORR in Fe–N systems, whereas in present Fe–P systems, oxides of Fe and P are found to be beneficial for ORR. Interestingly, after the introduction of Fe, mostly inactive P-doped carbon becomes active in acidic medium. We propose that this study will surely provide renewed insights into active sites for ORR in metal and heteroatom-doped carbon systems.