Enhanced Electrocatalytic Performance of Double-Shell Structured Nixfe2-Xp/Nife2o4 for Oxygen Evolution Reaction and Anion Exchange Membrane Water Electrolysis

Abstract

The development and characterization of a double-shell structured NixFe2-xP/NiFe2O4 electrocatalyst for enhanced oxygen evolution reaction (OER) and anion exchange membrane water electrolysis (AEMWE) are investigated. The electrocatalyst was synthesized via a sequential process involving solvothermal, calcination, and thermal phosphidation process using metal-organic framework (MOF) template. Physicochemical characterization techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electrochemical methods were employed to assess its structural, compositional, and electrocatalytic properties. The NixFe2-xP/NiFe2O4 exhibited superior electrocatalytic performance with low overpotentials and high turnover frequencies compared to NiFe-LDH, NiFe2O4, NiFe/NiFe2O4, and commercial RuO2. Additionally, the AEMWE cell equipped with a NixFe2-xP/NiFe2O4 anode showed outstanding performance (1.76 Vcell at 1000 mA cm−2). Enhanced electrocatalytic activity was attributed to its unique double-shell morphology, increased surface polarity from phosphorus incorporation, and efficient charge transfer facilitated by heterointerfaces between bimetallic phosphide and spinel oxide phases. This study underscores the promising potential of NixFe2-xP/NiFe2O4 as a high-performance electrocatalyst for sustainable water electrolysis applications.

Keywords: Anion exchange membrane water electrolysis, Electrocatalyst, Oxygen evolution reaction, Structural engineering, Heterostructure