One-pot hydrothermal synthesis of heteroatom co-doped with fluorine on reduced graphene oxide for enhanced ORR activity and stability in alkaline media

Abstract

Boron (B) or nitrogen (N) was co-doped with fluorine (F) on reduced graphene oxide (rGO) using a low cost and simplified one-pot hydrothermal treatment method avoiding complicated technology, such as gas phase deposition or high temperature pyrolysis method. X-ray photoelectron microscopy spectra revealed successful doping of heteroatoms into the rGO. The Brunauer-Emmett-Teller (BET) results demonstrated that high surface areas of B–F-rGO and N–F-rGO are favorable for O2 adsorption. Electrochemical evaluations show that B–F-rGO and N–F-rGO catalysts have improved oxygen reduction reaction (ORR) catalytic performance in alkaline media compared to B-rGO and N-rGO. A Koutechy-Levich (KL) analysis and rotating ring disk electrode (RRDE) measurements suggest that both electrocatalysts dominantly favor a 4-electron reduction process. These heteroatoms co-doped with fluorine on rGO exhibit remarkable long-term ORR stability than the Pt/C. These improved electrochemical properties indicate that B–F-rGO and N–F-rGO are promising candidates as cost-effective electrode materials for energy related applications.