Interfacial-Free-Water-Enhanced Mass Transfer to Boost Current Density of Hydrogen Evolution

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• High current density operation is crucial for efficient water electrolysis.
• Interfacial water structure significantly influences electrode reaction dynamics.
• The role of interfacial-free water (IFW) in modulating electrode behavior is underexplored.

Purpose of the Study:

• To investigate the effect of interfacial water structure on hydrogen evolution reaction (HER) performance.
• To explore the modulation of electrode behavior using IFW.
• To optimize alkaline water electrolysis for enhanced mass transfer and energy efficiency.

Main Methods:

• Designed platinum-coated nickel hydroxide on nickel foam (Pt@Ni(OH)₂-NF) electrodes.
• Studied HER performance across various current density ranges.
• Analyzed changes in interfacial water structure and their impact on reaction kinetics.

Main Results:

• Interfacial water structure changes alter the rate-determining step of HER with increasing current density.
• Pt@Ni(OH)₂-NF electrodes demonstrated excellent performance in alkaline electrolytes.
• Achieved 1000 mA cm^-2 at 114 mV overpotential, showcasing high efficiency.

Conclusions:

• Interfacial water structure is a key factor in regulating HER dynamics at high current densities.
• Utilizing IFW offers a novel approach to optimize mass transfer in alkaline water electrolysis.
• This research paves the way for more efficient and energy-saving hydrogen production technologies.