Enhanced hydrogen evolution reaction performance on nickel or cobalt doping engineered MoS₂: a first-principles study

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Molybdenum disulfide (MoS2) is a promising non-precious catalyst for the hydrogen evolution reaction (HER).
• The inert basal plane (BP) and limited charge transfer hinder MoS2's catalytic performance.
• Developing efficient HER electrocatalysts is crucial for sustainable hydrogen production.

Purpose of the Study:

• To systematically investigate the catalytic properties of various MoS2 surface models.
• To explore the impact of Ni and Co doping on MoS2's HER activity.
• To identify optimal MoS2 configurations for enhanced hydrogen evolution.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• 23 MoS2 surface models, including pristine and doped configurations (Ni, Co) at basal and edge sites, were analyzed.
• Key parameters such as Gibbs free energy of hydrogen adsorption (ΔGH) and formation energy (Ef) were computed.

Main Results:

• Pristine MoS2 basal plane exhibits negligible HER activity (ΔGH ≈ +1.99 eV).
• Ni and Co doping effectively activate both basal and edge MoS2 surfaces.
• S-edge doped models (S-edge 2Ni-sub and S-edge 3Co-sub) show near-optimal ΔGH values (+0.04 and -0.13 eV) with strong hydrogen adsorption.
• Negative formation energies indicate favorable synthesis of doped MoS2 catalysts.

Conclusions:

• Ni and Co doping are effective strategies to enhance MoS2 catalytic activity for HER.
• The S-edge 2Ni-sub and S-edge 3Co-sub MoS2 models are excellent candidates for efficient and scalable HER electrocatalysts.
• This study provides valuable insights for designing next-generation non-precious HER catalysts.