Metal–Organic Framework-Derived FeCo₂S₄/Co₃O₄ Heterostructure with Enhanced Electrocatalytic Performance for Oxygen Evolution and Hydrogen Evolution Reactions

Abstract

Herein, a versatile FeCo2S4/Co3O4 heterostructure consisting of zeolitic imidazolate framework ZIF-derived Co3O4 and FeCo-layered double hydroxide-derived Fe-doped Co sulfide is employed for the all-important alkaline full water splitting process. The heterostructure is prepared by combining pyrolysis and hydrothermal/solvothermal processes. The synthesized heterostructure possesses an electrocatalytically rich interface and renders excellent bifunctional catalytic performance. An overpotential of 139 mV for a standard cathodic current of 10 mA cm–2 with a low Tafel slope of 81 mV dec–1 is recorded for the hydrogen evolution reaction. An overpotential of 210 mV is observed for an anodic current of 20 mA cm–2 with a low Tafel slope of 75 mV dec–1 recorded for the oxygen evolution reaction. The full-symmetric two-electrode cell was capable of generating a current density of 10 mA cm–2 at a cell potential of 1.53 V and a low onset potential of 1.49 V. The symmetric cell architecture exhibits remarkable stability, as a negligible potential increase is observed for continuous water splitting over a 10 h period. With the reported performance, the heterostructure compares well with most of the excellent reported catalysts for alkaline bifunctional catalysts.

A high-performance electrocatalyst via graphitic carbon nitride nanosheet-decorated bimetallic phosphide for alkaline water electrolysis

“…53 It has been reported that the Tafel step is the rate-determining step if the Tafel slope is below 30 mV, the Volmer step if the Tafel slope is above 120 mV dec −1 , and the Heyrovsky step if the slope is between 40–120 mV dec −1 . 54 The Tafel slope of g-C 3 N 4 /NiCoP is in the range of 40–120 mV dec −1 , and the Heyrovsky step is the rate-determining step. The Tafel slope of g-C 3 N 4 /NiCoP is lower than those of the other electrocatalysts, indicating superior HER kinetics.…”

Three-Dimensional Indium Iron Selenide Nanoarchitecture as an Efficient and Durable Electrocatalyst for the Hydrogen Evolution Reaction

“…Growing concern over energy shortages and climate change has sparked an interest in developing renewable energy alternatives. , In this regard, hydrogen energy has drawn significant attention as a highly promising renewable energy source. − Hydrogen is a top candidate as a substitute for traditional fossil fuels as a result of its outstanding energy density, environmental friendliness, and renewability . By addressing both energy and environmental challenges, hydrogen offers potential solutions to these pressing issues. , Various methods have been discovered for producing hydrogen, with electrochemical generation standing out as an appealing approach involving the conversion of electric energy to generate highly pure hydrogen. , To facilitate this electrochemical generation of hydrogen, highly active electrocatalysts are employed.…”