Superhydrophilic/superaerophobic amorphous Ni₃S₂/NiMoS electrocatalyst for enhanced hydrogen evolution

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing cost-effective and highly active electrocatalysts is crucial for the hydrogen evolution reaction (HER).
• Existing catalysts often face limitations in activity, stability, or cost for industrial applications.

Purpose of the Study:

• To synthesize and characterize a novel Ni3S2/NiMoS nanoarray catalyst on nickel foam (Ni3S2/NiMoS/NF) for efficient HER.
• To investigate the synergistic effects of Ni3S2 and NiMoS, amorphous structure, and unique morphology on catalytic performance.
• To evaluate the catalyst's potential for industrial applications requiring high current densities.

Main Methods:

• Synthesis of Ni3S2/NiMoS nanoarrays on nickel foam using a facile method.
• Characterization of the catalyst's structure, composition, and morphology using advanced techniques.
• Electrochemical evaluation of HER performance in an alkaline medium, including activity, overpotential, and stability tests.
• Comparison with commercial platinum-based catalysts (Pt/C).

Main Results:

• Successfully synthesized Ni3S2/NiMoS/NF with an amorphous phase and a unique candied-haws shaped nanoarray structure.
• The combined Ni3S2 and NiMoS created extended heterointerfaces, enhancing HER in alkaline solutions.
• The amorphous nature provided abundant active sites, while the morphology ensured superhydrophilicity and underwater superaerophobicity for efficient mass transport and bubble release.
• Ni3S2/NiMoS/NF exhibited higher activity than Pt/C, even at high current densities, and demonstrated superior long-term stability.

Conclusions:

• The Ni3S2/NiMoS/NF catalyst is a highly efficient and stable electrocatalyst for the hydrogen evolution reaction.
• Its unique structural and compositional features contribute to its enhanced performance, surpassing commercial Pt/C.
• The catalyst shows significant potential for industrial applications, particularly those demanding high current densities and long-term durability.