Mesoporous iron sulfide nanoparticles anchored graphene sheet as an efficient and durable catalyst for oxygen reduction reaction

The fabrication of low-cost, highly efficient, and earth-abundant electrocatalysts for oxygen reduction reaction is critical to produce clean and sustainable fuel through an electrochemical process. Herein, a facile hydrothermal technique is used for the synthesis of iron sulfide/graphene hybrid for oxygen reduction reaction. Morphological analysis of the resulting catalyst reveals that iron sulfide nanoparticles are homogeneously embedded on the surface of reduced graphene oxide sheet. Electrochemical analysis of the hybrid exhibits remarkably improved catalytic performance for oxygen reduction reaction while achieving half wave potential of +0.845 V and onset potential of +1.0 V (versus reversible hydrogen electrode), along with outstanding long-term stability under alkaline conditions. In addition, the methanol tolerance ability and stability of the hybrid exceed the benchmark platinum/carbon product in alkaline condition. These outstanding activities of the hybrid are attributed to the merits of the interaction between iron sulfide nanoparticles and graphene. The results suggest the practicability of metal sulfide as a low cost and efficient alternative catalyst of platinum for oxygen reduction reaction.