Design of cobalt‐iron complex sulfides grown on nickel foam modified by reduced graphene oxide as a highly effect bifunctional electrocatalyst for overall water splitting

Abstract

Summary Development of high‐authority and rich‐in‐crust bifunctional electrocatalysts for overall water splitting has a great significance of clean energy storage and conversion with both of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). In this work, cobalt‐iron complex sulfides with the same metal molar ratio firmly grown on the surface of nickel foam modified by reduced graphene oxide (Co0.50Fe0.50S‐rGO@NF) was prepared and acted as a superior electrocatalyst for electrolyzing water. The same mole ratio of bimetallic‐cation doping can induce strong electron‐interaction between the complex sulfides and the surface of nickel foam carrier modified by reduced graphene oxide, which reduces the electronic adsorption energy required for HER and OER, as well as improves the electrocatalytic active area exposure. As a result, the optimal electrocatalyst of Co0.50Fe0.50S‐rGO@NF behaves excellent electrocatalytic performance with the overpotential of 189 mV @ η20 mA·cm−2 in 1.0 M KOH solution for OER and the overpotential of 155 mV @ η10 mA·cm−2 in 0.5 M H2SO4 solution for HER, respectively. A self‐built conventional two‐electrode electrolytic cell by using Co0.50Fe0.50S‐rGO@NF as the anode and cathode presents lower voltages of 1.39 and 1.66 V to deliver the current density of 10 mA·cm−2 in 1.0 M KOH and 1.0 M PBS electrolytes, respectively. This study underlines the synergism of the bimetallic‐cation doping complex sulfides loaded on nickel foam modified by rGO for boosting the electrocatalytic activity of overall water splitting.

Design of a High-Efficiency Bifunctional Electrocatalyst: Rich-Nitrogen-Doped Reduced Graphene Oxide-Modified Carbon Cloth-Growing Nickel–Iron Complex Oxides for Overall Water Splitting

“…The as-prepared electrocatalysts were used in 1.0 M KOH electrolyte solution for OER/HER and in 0.5 M H 2 SO 4 solution for HER. The linear sweep voltammetry (LSV) technique was conducted with a scan rate of 1 mV·s –1 , and the potentials could be converted into those for the reversible hydrogen electrode (RHE) on the basis of the Nernst equation E ( vs RHE) = E ( vs Ag/AgCl) + 0.059 × pH + 0.197 V . All of the electrochemical data in this work were collected without iR compensation, and the electrochemical measurements were implemented at room temperature.…”

CoNi2S4 Nanosheets on Carbon Cloth Using a Deep Eutectic Solvent Strategy as Bifunctional Catalysts for Water/Simulated Seawater Electrolysis

“…Self-supported electrodes with nanostructure catalysts growing on a porous conductive substrate prevent the catalysts from falling off from substrates. 15 Carbon cloth (CC), a commercially conductive substrate, has enormous promise for the fabrication of self-supported flexible electrodes. 16 However, because of their hydrophobic property, CC substrates typically suffer from low mass loading, limiting their large-scale application.…”

“…Self-supported electrodes with nanostructure catalysts growing on a porous conductive substrate prevent the catalysts from falling off from substrates . Carbon cloth (CC), a commercially conductive substrate, has enormous promise for the fabrication of self-supported flexible electrodes .…”

Synchronous Surface‐Interface and Crystal‐Phase Engineered Multifaceted Hybrid Nanostructure of Fe‐(1T)‐VSe2 Nanosheet and Fe‐CoSe2 Nanorods Doped with P for Rapid HER and OER, Kinetics

“…[29] Bimetallic TMDCs, on the other hand, showed much higher promises than the monometallic-TMDCs as the adsorption energy of the intermediates is either too strong or too weak for monometallic-TMDCs and requires further electronic structure modulation by the second metal. [32][33][34][35][36] In the present context, fabricating bimetallic composite catalysts of Fe-Co may well meaningfully expand the electrochemical efficiency by creating promising interfaces for adsorbing the active species and encouraging charge transfer amongst diverse components. [10,22,33,34,37,38] Predominantly, bimetallic Fe-Co-TMDCs could generate tunable electronic states with abundantly rich active sites, which initiate exceptional catalytic performance.…”