Surface selectivity of Ni₃S₂ toward hydrogen evolution reaction: a first-principles study

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Developing efficient catalysts for the hydrogen evolution reaction (HER) is crucial for clean hydrogen energy production.
• The surface structure of catalytic materials significantly influences their performance in HER.

Purpose of the Study:

• To investigate the phase stability, surface structures, electronic properties, and HER catalytic properties of low-index Ni3S2 surfaces.
• To identify specific Ni3S2 surface terminations with high catalytic activity and stability for HER.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to study various low-index surfaces of Ni3S2.
• Calculations included phase stability, surface structure analysis, electronic properties, and Gibbs free energy of adsorption for HER intermediates.
• Thermodynamic stability of different Ni3S2 surfaces and their catalytic activity were evaluated.

Main Results:

• Several S-rich and stoichiometric Ni3S2 surfaces, including (0001)A, (101[combining macron]0)B, and (101[combining macron]0)C, were found to be thermodynamically stable.
• The (0001)A, (101[combining macron]0)B, and (101[combining macron]0)C surfaces exhibit high catalytic activity for HER, with Gibbs free energies comparable to or better than Pt(111).
• The (101[combining macron]0)B surface demonstrated the highest density of active sites within an overpotential range of 0 to 300 mV.

Conclusions:

• Specific Ni3S2 surfaces possess excellent potential for HER catalysis due to their stability and activity.
• The findings provide significant insights into surface selectivity for Ni3S2 in HER.
• This research offers a pathway for optimizing Ni3S2 performance by controlling exposed surfaces for enhanced hydrogen production.