Artificial Heterointerfaces Achieve Delicate Reaction Kinetics towards Hydrogen Evolution and Hydrazine Oxidation...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical water splitting for hydrogen production is hindered by the slow oxygen evolution reaction (OER).
• Replacing OER with the hydrazine oxidation reaction (HzOR) offers a promising alternative for efficient hydrogen generation.

Purpose of the Study:

• To develop advanced bifunctional electrocatalysts for efficient hydrogen evolution reaction (HER) and HzOR.
• To investigate the catalytic activity and performance of hierarchical porous nanosheet arrays with Ni3N-Co3N heterointerfaces.

Main Methods:

• Fabrication of hierarchical porous nanosheet arrays with Ni3N-Co3N heterointerfaces on Ni foam.
• Electrochemical characterization of the catalyst for HER and HzOR.
• Testing of a two-electrode overall hydrazine splitting (OHzS) electrolyzer.
• Density Functional Theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• The catalyst exhibited superior HER and HzOR activity, with low working potentials of -43 mV and -88 mV for 10 mA cm⁻², respectively.
• Achieved an industry-level current density of 1000 mA cm⁻² at 200 mV for HzOR.
• The OHzS electrolyzer demonstrated efficient performance at low cell voltages.
• DFT calculations revealed that heterointerfaces optimize hydrogen adsorption and dehydrogenation kinetics.

Conclusions:

• Hierarchical porous nanosheet arrays with Ni3N-Co3N heterointerfaces are highly effective bifunctional electrocatalysts.
• This catalyst design offers a promising strategy for energy-saving hydrogen production via hydrazine splitting.
• The findings pave the way for practical, efficient hydrogen generation technologies.