FeNi nanoparticles embedded porous nitrogen-doped nanocarbon as efficient electrocatalyst for oxygen evolution reaction

Abstract

It is significant and challenging to develop a highly active, hyper stable and low-cost novel oxygen evolution reaction (OER) electrocatalyst to replace the noble metal-based electrocatalysts for large-scale electrocatalytic water splitting. To settle such issue, for the first time, FeNi alloy nanosphere homogenously embedded porous nitrogen-doped nanocarbon (FeNi@NC) hybrid has been synthesized by pyrolyzing a precursor composite composed of nickel hexacyanoferrate and nitrogen-doped nanocarbon under the inert atmospheres without any further post-treatments. The as-prepared uniform FeNi alloy nanosphere embedded porous nitrogen-doped nanocarbon (FeNi@NC) hybrid exhibits a very low overpotential of 298 mV (vs. RHE) at current density of 10 mA cm−2, a small Tafel slope of 48.4 mV dec−1 and excellent stability after 1.26 × 105 s (more than 35 h) at 10 mA cm−2 towards OER. In addition, the mass normalized activity of FeNi@NC hybrid measured at fixed potential of 1.7 V (vs. RHE) is 295.9 A g−1. The outstanding OER performance can be attributed to the porous nitrogen-doped nanocarbon structure, high specific surface area as well as good electrical conductivity. The results indicate that this work provides a new strategy to fabricate other transition bimetallic alloy embedded porous nitrogen-doped nanocarbon hybrid as OER electrocatalysts in the further.