Hydrothermal synthesis of boron-nitrogen-sulfur tri-doped reduced graphene oxide for PEM fuel cell applications

The commercialization and scalability of proton exchange membrane (PEM) fuel cells have been hindered by the sluggish kinetics of the oxygen reduction reaction (ORR) and the high cost of platinum electrocatalysts. Heteroatom-doped graphene has emerged as a promising alternative catalyst due to the synergistic effects of the dopants on the graphene structure. This study aims to synthesize boron, nitrogen, and sulfur tri-doped reduced graphene oxide (BNS-rGO) to elucidate the role of dopants in enhancing the electrocatalytic activity of doped graphene. In this study, B-, N-, and S-tri-doped graphene was synthesized via a one-pot hydrothermal reaction of graphene oxide (GO) with boric acid and thiourea. A comprehensive characterization of the synthesized materials was conducted using various analytical techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), scanning electron microscopy (SEM), and cyclic voltammetry. These analyses confirm the successful incorporation of B, N, and S dopants into the graphene structure. The tri-doped BNS-rGO catalyst exhibited superior ORR activity and a higher current density. This enhanced performance can be attributed to the reduced number of oxygen-containing functional groups, increased surface area, and improved electrical conductivity of the doped graphene structure. This study demonstrated the potential of metal-free heteroatom-doped graphene structures for the development of cost-effective and stable ORR electrocatalysts for PEM fuel cells and other energy applications. The successful synthesis and characterization of BNS-rGO provide valuable insights into the role of dopants in enhancing the electrocatalytic activity of graphene-based materials.