Defect and Doping Engineered Penta-graphene for Catalysis of Hydrogen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Hydrogen fuel production via water electrolysis is crucial for sustainable energy.
• Developing cost-effective and stable electrocatalysts for the hydrogen evolution reaction (HER) is a key challenge.
• Noble metal catalysts are effective but prohibitively expensive for widespread use.

Purpose of the Study:

• To design and investigate a novel two-dimensional (2D) electrocatalyst based on doped penta-graphene (PG) for HER.
• To evaluate the stability, electronic properties, and catalytic performance of the designed PG electrocatalyst.
• To identify optimal doping strategies and defect configurations for enhanced HER activity.

Main Methods:

• First-principles calculations were employed to design and analyze the electrocatalyst.
• The Gibbs free energy (ΔG_H) was calculated as the descriptor for HER activity.
• Analysis of electron charge density differences and Bader charges was performed to understand charge transfer.

Main Results:

• A defect and N-, S-, P-doped penta-graphene (PG) was designed as a 2D electrocatalyst.
• Optimal HER performance was achieved with a ΔG_H of 0 eV, attributed to C2 vacancies and P doping at C1 sites.
• Increased charge transfer from PG to hydrogen correlates with a ΔG_H closer to zero.

Conclusions:

• The designed doped PG exhibits excellent potential as a low-cost, high-performance electrocatalyst for HER.
• The study provides insights into the relationship between electronic structure, charge transfer, and catalytic activity.
• The Volmer-Heyrovsky mechanism is identified as the preferred pathway for HER on this catalyst.