Electrocatalytic activity of a β-Sb two-dimensional surface for the hydrogen evolution reaction

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Hydrogen energy is a key clean energy source.
• Developing efficient, cost-effective, and stable catalysts is crucial for hydrogen production.
• Platinum-based catalysts are effective but expensive for the hydrogen evolution reaction (HER).

Purpose of the Study:

• To investigate the catalytic activity of 2D β-antimony (Sb) surfaces doped with main-group elements for the HER.
• To identify promising non-platinum catalysts for efficient hydrogen production.
• To understand the underlying mechanisms of enhanced catalytic activity.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to study the electronic and catalytic properties of doped β-Sb monolayers.
• Systematic doping with group VIA elements (O, S, Se, Te) and other main-group elements (N, P, As) was performed.
• Analysis of electronic structures, including density of states (DOS) and Gibbs free energy, was conducted.

Main Results:

• Doping β-Sb monolayers with group VIA elements significantly enhances HER catalytic activity.
• Se@Sb and O@Sb structures (2.78% doping) and S@Sb (5.56% doping) exhibit catalytic activity comparable to Pt(111).
• These doped structures remain energetically stable, and their performance can be further optimized by biaxial strain.

Conclusions:

• Novel non-platinum HER catalysts based on doped antimonene are proposed.
• The enhanced activity is attributed to hole states in lone pair electrons introduced by group VIA dopants.
• The density of states at the Fermi level is identified as a descriptor for hydrogenation Gibbs free energy, providing insights for future catalyst design.