LiNiO/Ni Heterostructure with Strong Basic Lattice Oxygen Enables Electrocatalytic Hydrogen Evolution with Pt-like...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Sustainable hydrogen economy relies on low-cost hydrogen production via water electrolysis.
• Current limitations stem from the scarcity of active and robust electrocatalysts made from earth-abundant materials.

Purpose of the Study:

• To develop and characterize a novel heterostructure electrocatalyst for efficient hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR).
• To investigate the catalytic mechanisms enabled by the unique material composition and structure.

Main Methods:

• Synthesis of a heterostructure composed of Ni-deficient LiNiO nanoclusters and Ni nanocrystals.
• Electrochemical evaluation of the catalyst's performance for HER and HOR in acidic, neutral, and alkaline electrolytes.
• Analysis of the catalyst's structural and electronic properties to understand the reaction mechanisms.

Main Results:

• The novel heterostructure exhibits exceptional HER activity, achieving 10 mA cm⁻² at low overpotentials (20 mV acidic, 50 mV neutral, 36 mV alkaline).
• The catalyst demonstrates superior activity for the hydrogen oxidation reaction (HOR) in alkaline electrolytes.
• The presence of lattice oxygen species and interfacial junctions facilitates water splitting and promotes catalytic efficiency.

Conclusions:

• The developed earth-abundant electrocatalyst is among the most active Pt-free catalysts for HER to date.
• The unique heterostructure design offers a promising pathway for cost-effective and sustainable hydrogen production and utilization.
• The catalyst's bifunctional activity for both HER and HOR enhances its potential for integration into hydrogen-based energy systems.