Heterogeneous Synergetic Effect of Metal-Oxide Interfaces for Efficient Hydrogen Evolution in Alkaline Solutions

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Water dissociation in alkaline media is a significant hurdle for hydrogen evolution reactions (HERs).
• Effective catalysts require balanced adsorption energies for OH, H, and H2.
• Developing efficient and stable electrocatalysts is crucial for hydrogen production.

Purpose of the Study:

• To synthesize and characterize a novel Ni17W3/WO2 catalyst for enhanced HER activity in alkaline electrolytes.
• To investigate the role of hierarchical interfaces in optimizing water dissociation and hydrogen evolution.
• To understand catalyst surface evolution under cathodic potentials for improved stability.

Main Methods:

• Synthesis of Ni17W3/WO2 catalyst on Ni foam substrate.
• Electrochemical characterization including overpotential and Tafel slope measurements.
• Surface analysis using various techniques to study catalyst evolution under different potentials.

Main Results:

• The Ni17W3-NiWO4 and Ni17W3-WO2 interfaces were found to accelerate water dissociation and facilitate H2 desorption, respectively.
• High coverage of large Ni17W3 nanoparticles created a stable interface, promoting the Volmer-Tafel reaction pathway.
• The Ni17W3/WO2 catalyst demonstrated exceptional HER activity with a low overpotential (48 mV at 10 mA cm-2) and a Tafel slope of 33 mV dec-1.

Conclusions:

• Engineered hierarchical interfaces in low-cost catalysts can significantly boost HER performance in alkaline solutions.
• The developed Ni17W3/WO2 catalyst offers a promising pathway for efficient and cost-effective hydrogen production.
• This work highlights the potential of tandem catalyst systems for optimizing electrochemical reactions.