Enhanced electrocatalysis for alkaline hydrogen evolution by Mn doping in a Ni₃S₂ nanosheet array.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient and cost-effective catalysts are needed for the hydrogen evolution reaction (HER).
• Nickel sulfide-based materials show promise but require further optimization for enhanced performance.
• Earth-abundant elements are preferred for sustainable energy applications.

Purpose of the Study:

• To develop a highly efficient and durable catalyst for alkaline hydrogen evolution.
• To investigate the effect of manganese doping on the HER performance of Ni3S2 nanosheet arrays.
• To provide insights into designing advanced electrocatalysts for hydrogen production.

Main Methods:

• Synthesis of manganese-doped Ni3S2 nanosheet arrays on nickel foam (Mn-Ni3S2/NF).
• Electrochemical characterization using techniques like linear sweep voltammetry and electrochemical impedance spectroscopy.
• Evaluation of catalytic activity and durability in alkaline media (1.0 M KOH).

Main Results:

• The Mn-Ni3S2/NF catalyst exhibited a low overpotential of 152 mV at 10 mA cm-2 for alkaline HER.
• This represents a significant improvement, requiring 46 mV less overpotential compared to undoped Ni3S2/NF.
• The developed catalyst demonstrated excellent long-term electrochemical durability.

Conclusions:

• Manganese doping effectively enhances the catalytic activity and stability of Ni3S2 for HER.
• Mn-Ni3S2/NF is a promising earth-abundant catalyst for efficient alkaline hydrogen evolution.
• This study offers valuable guidance for the rational design of next-generation HER electrocatalysts.