Synergistic Hydrogen Microenvironment Modulation Enabling Superior Hydrogen Evolution Reaction Activity in Neutral...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The neutral hydrogen evolution reaction (HER) is crucial for sustainable energy but faces challenges due to a strong hydrogen-bonding network and limited proton supply.
• Nickel-iron layered double hydroxide (LDH) is HER-inert, necessitating strategies to improve its catalytic activity.

Purpose of the Study:

• To enhance the neutral HER activity of nickel-iron LDH.
• To investigate the synergistic effects of nickel nanoparticle (Ni NP) decoration and tungstate intercalation on the hydrogen microenvironment of LDH.

Main Methods:

• Decoration of HER-inert LDH with Ni NPs and intercalation of tungstate.
• Theoretical simulations to understand microenvironment modulation.
• Operando electrochemical characterizations to validate catalytic performance.

Main Results:

• Synergistic modulation of the hydrogen microenvironment by Ni NPs and tungstate.
• Ni NPs enhance local electric fields, disrupt hydrogen bonds, and promote water dissociation.
• Tungstate regulates electronic structure, accelerates dehydration, optimizes H* adsorption/recombination, and enriches H3O+.
• Achieved ultralow overpotentials of 14 mV (10 mA cm⁻²) and 239 mV (1000 mA cm⁻²).
• Demonstrated outstanding stability of 600 hours at 1000 mA cm⁻².

Conclusions:

• Co-modification of LDH with Ni NPs and tungstate significantly boosts neutral HER activity and stability.
• Synergistic modulation of the hydrogen microenvironment offers a novel approach for designing efficient HER electrocatalysts.