MOF-Derived Porous Fe₃O₄/RuO₂-C Composite for Efficient Alkaline Overall Water Splitting

Abstract

Development of highly active, durable, bifunctional electrocatalysts for overall water splitting is of great importance to enhance the use of hydrogen energy. Herein, we synthesize a porous and interfaces-rich Fe3O4/RuO2-C composite from the Metal organic frameworks (MOF) material for overall water splitting in alkaline media. The Fe3O4/RuO2-C catalyst showed superior oxygen evolution reaction (OER) with high faradic efficacy. It requires 268 mV overpotential to achieve the current density of 20 mA/cm2. The catalyst also exhibited good hydrogen evolution reaction (HER) with a current density of 10 mA/cm2 at an overpotential of 94 mV. The stability test confirmed a remarkable long-term OER and HER stability of this catalyst in alkaline media. In addition, the Fe3O4/RuO2-C catalyst was also used as cathode and anode material for overall water splitting. It showed superior activity and stability in alkaline media with 10 mA/cm2 current density at 1.595 V cell potential. The excellent electrocatalytic activity of the Fe3O4/RuO2-C catalyst can be attributed to its porous structure, synergistic interaction between the components, the presence of hetero-interfaces, high electrochemical surface area etc. This work may provide an opportunity to design a bifunctional electrocatalyst for the development of anion exchange membrane water electrolyzers (AEMWEs).

Electrocatalytic Oxidation of Urea and Ethanol on Two-Dimensional Amorphous Nickel Oxide Encapsulated on N-Doped Carbon Nanosheets

“…This method can provide clean and efficient ultra-pure hydrogen . In the water electrolysis method, there are two sequential half-reactions: oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), which take place at the anode and cathode, respectively. − The HER is a two-electron process and can easily catalyze at low overpotentials . However, the OER is a four-electron process that is believed as a sluggish process, therefore, requires a large overpotential .…”

One-Dimensional Ni-MIL-77 Metal–Organic Framework as an Efficient Electrode Nanomaterial for Asymmetric Supercapacitors

“…These new porous crystalline materials are made up of organic linkers and metal nodes and are described as metal− organic frameworks (MOFs). 17,18 In recent years, MOFs have become more widely used in energy storage devices, such as supercapacitors, battery-supercapacitor hybrid devices, and rechargeable batteries, due to their impressive features, like tailorable pore size and shape, high surface area, diverse functionalization, and controllable chemical composition. 19 However, the limited practical applicability of MOFs in the area of energy storage is because of their poor intrinsic electrical conductivity and low exposed electroactive sites.…”

One Bifunctional Electrocatalyst Derived from Nickel MOF for Urea Oxidation Reaction and Hydrogen Evolution Reaction

“…Shekhawat reported MOF-derived catalysts requiring an overpotential of only 268 mV to accomplish a current density of 20 mA·cm –2 in OER. In addition, only 94 mV overpotential is needed to accomplish a current density of 10 mA·cm –2 in HER …”

“…In addition, only 94 mV overpotential is needed to accomplish a current density of 10 mA•cm −2 in HER. 32 In this paper, we first synthesized a novel Ni-MOF (Ni-bza, Hbza = 4-(1H-1,2,4-triazol-1-yl) by a hydrothermal method and pyrolyzed it to obtain Ni-MOF-derived carbon material Ni-bza-T, which was applied in hydrogen evolution and urea oxidation reactions.…”