Self-Reconstructed Amorphous CoO_x/NiCoB Heterostructure Catalysts for Enhanced HER Performance

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Amorphous electrocatalysts can transform into active species via in situ reconstruction.
• Developing efficient and stable pre-catalysts is crucial for electrochemical reactions.

Purpose of the Study:

• To synthesize and characterize a novel amorphous Ni-Co-B alloy pre-catalyst for the hydrogen evolution reaction (HER).
• To investigate the in situ reconstruction mechanism and identify the active sites.
• To evaluate the catalytic performance and stability of the reconstructed catalyst.

Main Methods:

• Electroless plating to synthesize amorphous Ni-Co-B alloy on nickel foam.
• X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) for chemical state analysis.
• Morphological characterizations (e.g., SEM, TEM) to study structural evolution.
• Electrochemical testing to assess HER performance and stability.
• Theoretical calculations to understand the catalytic mechanism.

Main Results:

• Amorphous Ni-Co-B alloy pre-catalysts were successfully synthesized.
• In situ reconstruction during HER led to the formation of amorphous CoOₓ nanosheet arrays on the NiCoB phase.
• The CoOₓ/NiCoB heterostructure exhibited a low overpotential (209 mV at 500 mA cm⁻²) and excellent stability (300 h).
• Theoretical calculations confirmed favorable electron reconfiguration and optimized hydrogen adsorption at the heterostructure interfaces.

Conclusions:

• The amorphous Ni-Co-B alloy serves as an effective pre-catalyst for HER through in situ reconstruction.
• The CoOₓ/NiCoB heterostructure represents a highly active and stable electrocatalyst for hydrogen production.
• Interface engineering and synergistic effects are key to enhancing HER performance.