Enhanced electrocatalytic performance of double-shell structured NixFe2-xP/NiFe2O4 for oxygen evolution reaction and anion exchange membrane water electrolysis

초록

This research proposes the development and characterization of a double-shell structured nickel-iron phosphide/ oxide heterostructure (NixFe2-xP/NiFe2O4) electrocatalyst for enhanced oxygen evolution reaction (OER) and anion exchange membrane water electrolysis (AEMWE). The electrocatalyst is 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 are employed to assess its structural, compositional, and electrocatalytic properties. The NixFe2-xP/NiFe2O4 exhibits superior electrocatalytic performance with low overpotentials and high turnover frequencies compared to NiFe-LDH, NiFe2O4, NiFe/NiFe2O4, and commercial IrO2. Additionally, the AEMWE cell equipped with a NixFe2-xP/NiFe2O4 anode shows outstanding performance (1.76 Vcell at 1000 mA cm-2). Enhanced electrocatalytic activity is 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.

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