Active-site-enriched dendritic crystal Co/Fe-doped Ni₃S₂ electrocatalysts for efficient oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Green Energy

Background:

• Electrochemical water splitting is crucial for sustainable energy solutions.
• Efficient and affordable catalysts are needed to overcome challenges in the oxygen evolution reaction (OER).
• Non-noble metal catalysts are highly sought after for OER applications.

Purpose of the Study:

• To develop efficient and low-cost non-noble metal electrocatalysts for the oxygen evolution reaction (OER).
• To investigate the effect of Co/Fe bimetal doping on Ni₃S₂ for enhanced OER performance.
• To explore a simple hydrothermal synthesis method for creating advanced electrocatalysts.

Main Methods:

• A single-step hydrothermal method was employed to synthesize Co/Fe bimetal-doped Ni₃S₂ (CF-NS) electrocatalysts.
• The doping ratio of bimetals was adjusted to optimize catalyst properties.
• Electrochemical characterization techniques were used to evaluate OER activity and stability.

Main Results:

• The optimized CF-NS catalyst exhibited high OER activity, requiring a low overpotential of 146 mV at 10 mA cm^-2.
• Characterization revealed increased active sites, improved electroconductivity, and optimized electronic structure due to Co/Fe doping.
• The catalyst demonstrated excellent stability, operating continuously for at least 86 hours.
• Fe-induced high valence Ni contributed to the formation of the active NiOOH phase, and dendritic morphology enhanced active site accessibility.

Conclusions:

• The Co/Fe-doped Ni₃S₂ electrocatalysts show significant promise for efficient and stable oxygen evolution reactions.
• The developed synthesis strategy offers a viable route for designing cost-effective, high-performance non-precious metal catalysts.
• This work contributes to the advancement of transition metal sulfide catalysts for sustainable energy applications.