In situ synthesis of FeNi3/(Fe,Ni)9S8/Ni4S3/C nanorods and enhancement of oxygen evolution reaction properties

NiFe-based nanomaterials have emerged as highly promising catalysts to replace platinum, ruthenium and iridium for oxygen evolution reaction (OER), in “green hydrogen” production process through water splitting. Using iron (2+) sulfate and nickel acetate as the raw materials, with the molar ratio of Ni acetate to iron (2+) sulfate controlled at 8:5, the concentration of metal-ion was 0.6 mol/L, and precursor fibers rich in Ni2+, Fe2+, and SO4 2− were prepared using electrospinning technology, with polyvinyl alcohol acting as the colloid. Subsequently, composite nanorods rich in the elements of Ni, Fe, S, and C were successfully obtained at a heat treatment temperature of 1000°C in an Ar gas atmosphere. The results demonstrate that the nanorod samples possessed a surface diameter of ~200 nm, and the main phases of the nanorods after heat treatment at 1000°C included FeNi3 alloy, (Fe,Ni)9S8, Ni4S3, and amorphous C. Electrochemical performance tests conducted in a 1.0 mol/L KOH solution exhibited excellent oxygen evolution reaction properties of the catalysts prepared using FeNi3/(Fe,Ni)9S8/Ni4S3/C nanorods as the materials. The overpotential was about 258.6 mV of the catalyst material at 10 mAcm−2.