Hexagonal bismuth-nanoplate encrusted rGO – catalyzed ammonia production via electrochemical nitrogen reduction reaction

Herein, hexagonal bismuth nanoplate-incorporated reduced graphene oxide (Bi-hNP/rGO) nanocomposites were developed and evaluated as cathode material for ammonia production via electrochemical nitrogen reduction reaction (ENRR) at ambient conditions. Comprehensive characterization of the as-synthesized nanocomposites was performed using various physical as well as electrochemical methods. In acidic medium, the Bi-hNP/rGO electrode exhibited a notable ammonia production rate of 14.2 μg h−1 mg−1 at an applied potential of −0.25 V vs. RHE (reversible hydrogen electrode), along with a FE (Faradaic efficiency) of 7.45% at −0.15 V vs. RHE. The better electrocatalytic performance is owed to the high selectivity of bismuth toward ENRR over HER (Hydrogen evolution reaction), and the synergistic effect of rGO, which provides abundant active sites and high surface area for uniform Bi nanoparticle dispersion. Additionally, the Bi-hNP/rGO nanocomposite demonstrated excellent electrochemical stability. These results establish Bi-hNP/rGO as a promising electrocatalyst for efficient and selective ammonia synthesis via ENRR with high durability.