Tiny Ni₃S₂ boosting MoS₂ hydrogen evolution in alkali by enlarging coupling boundaries and stimulating basal plane

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The hydrogen evolution reaction (HER) in alkaline media is crucial for water electrolysis but is limited by slow kinetics.
• Developing efficient electrocatalysts is key to overcoming these limitations for industrial applications.

Purpose of the Study:

• To synthesize and characterize a novel Ni3S2/MoS2/CC catalytic electrode for improved alkaline HER.
• To investigate the synergistic effects of Ni3S2 modification on MoS2 for enhanced catalytic activity.

Main Methods:

• A two-step hydrothermal method was employed to synthesize the Ni3S2/MoS2/CC catalyst.
• Electrochemical performance was evaluated, including overpotentials required for specific current densities and stability tests.

Main Results:

• The Ni3S2/MoS2/CC catalyst demonstrated significantly enhanced HER kinetics in alkaline solution.
• Overpotentials of 189.4 mV and 240 mV were required for current densities of 100 mA·cm⁻² and 300 mA·cm⁻², respectively.
• The catalyst's performance surpassed that of Pt/C at high current densities ( > 261.7 mA·cm⁻²).

Conclusions:

• Ni3S2 modification effectively facilitates water adsorption and dissociation, boosting alkaline HER.
• The unique morphology provides abundant active sites, enhancing catalytic efficiency.
• The Ni3S2/MoS2/CC electrode presents a promising alternative to noble metal catalysts for industrial water electrolysis.