Iron-Nickel Nanoparticles as Bifunctional Catalysts in Water Electrolysis

Abstract Iron−nickel nanoparticles (Fe−Ni NPs) were successfully synthesized in various stoichiometries by using the inverse micelle method followed by combustion at 500 °C for 12 h in H 2 . Ni‐rich Fe−Ni NPs crystallize in a face‐centered cubic (fcc) structure, whereas Fe‐rich Fe−Ni NPs stabilize in body‐centered cubic (bcc) structure. Fe−Ni NPs operate as bifunctional electrode materials at room temperature in alkaline medium and show enhanced electrocatalytic activity in the electrolysis of water to H 2 evolution and O 2 evolution reactions (HER and OER) at low onset potential versus Ag/AgCl as the reference electrode. A low Tafel slope was also detected for Fe 2 Ni NPs (ca. 470 mV/dec) in the water oxidation reaction. Bifunctional electrocatalysts are significant in renewable and clean energy processes like hydrogen–oxygen fuel cells, metal–oxygen batteries, and so forth.