Electrolyte modification method induced atomic arrangement in FeO/NF nanosheets for efficient overall water splitting

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage and Conversion

Background:

• Transition metal-based electrocatalysts are vital for energy storage and conversion.
• Designing electrodes with abundant active sites and high electrical conductivity is key.
• Current methods often face limitations in catalytic efficiency and stability.

Purpose of the Study:

• To investigate fluoroethylene carbonate (FEC) as an electrolyte additive for enhancing electrocatalyst performance.
• To develop a novel strategy for improving the catalytic activity of iron oxide (FeO) on nickel foam (NF).
• To explore the potential of modified FeO/NF as bifunctional electrocatalysts for water splitting.

Main Methods:

• Electrolyte modification using fluoroethylene carbonate (FEC) additive during electrochemical conversion.
• Synthesis and characterization of FeO/NF electrocatalysts with varying FEC concentrations.
• Electrochemical testing of the modified catalysts for hydrogen evolution reaction (HER) and overall water splitting.

Main Results:

• The optimal FeO/NF-Li-FEC1 sample exhibited excellent HER activity, achieving a low overpotential of 222 mV at 200 mA cm-2.
• As bifunctional electrocatalysts, FeO/NF-Li-FEC1 enabled a water-splitting device to reach 10 mA cm-2 at a low cell voltage of 1.56 V.
• Enhanced performance is attributed to optimized atomic arrangement, rich active sites, improved electronic structure, and a thinner solid electrolyte interphase (SEI) layer.

Conclusions:

• Electrolyte modification with FEC is an effective strategy to boost the catalytic activity of FeO/NF.
• The modified FeO/NF-Li-FEC1 demonstrates high efficiency for both HER and overall water splitting.
• This study presents a novel approach for designing cost-effective, high-performance electrode materials for electrochemical energy applications.