Highly Active, Nonprecious Electrocatalyst Comprising Borophene Subunits for the Hydrogen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient, nonprecious electrocatalysts is crucial for large-scale water-splitting technologies.
• Achieving high performance at industrially relevant current densities (e.g., 1000 mA/cm²) remains a significant challenge.

Purpose of the Study:

• To identify and characterize a novel, earth-abundant electrocatalyst for the hydrogen evolution reaction (HER).
• To investigate the catalytic activity and stability of α-phase molybdenum diboride (α-MoB₂) for HER, particularly at high current densities.

Main Methods:

• Combined theoretical calculations and experimental validation were employed.
• Density functional theory (DFT) was used to study surface properties and active sites.
• Electrochemical measurements were performed to assess catalytic performance and stability.

Main Results:

• α-phase molybdenum diboride (α-MoB₂) was identified as a highly efficient, noble metal-free HER electrocatalyst.
• Theoretical studies revealed α-MoB₂ maintains high activity even at high hydrogen coverage, with a high density of active sites.
• Experimental results confirmed α-MoB₂ delivers current densities around 1000 mA/cm² with excellent stability.

Conclusions:

• α-MoB₂ exhibits superior HER performance, especially at high current densities, due to its high conductivity, abundant active sites, and favorable mass transport.
• This discovery offers a promising pathway towards cost-effective and practical water-splitting applications.