3D graphene aerogel supported FeNi-P derived from electroactive nickel hexacyanoferrate as efficient oxygen evolution catalyst

Abstract

It is essential to design an oxygen evolution reaction (OER) electrocatalyst with smaller overpotential to improve water electrolyzer efficiency. Here, we report a simple method to incorporate nickel hexacyanoferrate into the three-dimensional (3D) graphene aerogel (GA) structure (NiHCF/GA), through which we have derived OER active FeNi-P/GA catalyst by heating with the phosphide source. Structural characterization data disclosed that the NiHCF derived FeNi-P particles were uniformly distributed in the 3D GA network. The obtained FeNi-P/GA catalyst exhibits precursor ([K3Fe(CN)6] and NiCl2) concentration-dependent electrocatalytic activity towards OER. Linear sweep voltammetry (LSV) study shows OER on the optimized FeNi-P/GA catalyst surface commenced at 1.46 V vs. RHE and demands only 280 mV overpotential to achieve the benchmark current density of 10 mA.cm−2. Also, the FeNi-P/GA catalyst displayed a Tafel slope of 43 mV.dec−1, suggesting its superior OER performance in alkaline condition.