A facile conversion of a Ni/Fe coordination polymer to a robust electrocatalyst for the oxygen evolution reaction

Abstract

Cost-efficient, active, and durable electrocatalysts are highly desired to facilitate the oxygen evolution reaction (OER) for water splitting. On the basis of a Ni hexacyanoferrate (NiHCF) Prussian blue-type coordination polymer, a facile route was developed to fabricate robust Ni/Fe composites for the OER in alkaline electrolyte. The obtained catalysts were characterized by SEM, XRD, FTIR, EDS and XPS methods, and the catalytic activity was evaluated by the electrochemical technique. The Ni/Fe catalyst, which was identified as mixed Ni/Fe oxides, afforded an OER onset overpotential of 310 mV and a Tafel slope of ∼44 mV per decade in alkaline medium. The Ni/Fe composite also exhibits excellent durability in the electrocatalysis process. No obvious degradation of the OER catalytic density was observed during the cyclic voltammetry (CV) process.