Interface Engineering: Heterogeneous Nickel-Iron Sulfide Decorated Nitrogen-Doped-Graphene for Efficient Water...

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Urgent need for efficient and stable non-precious metal electrocatalysts for renewable energy conversion.
• Existing catalysts often lack the required efficiency and long-term stability for applications like water splitting.

Purpose of the Study:

• To synthesize a novel heterogeneous catalyst ((Ni,Fe)-Sx-Fe/NGr) for enhanced water splitting performance.
• To investigate the catalytic activity and stability of the developed material for oxygen and hydrogen evolution reactions.

Main Methods:

• Facile solvothermal and annealing phase transition technology used for catalyst synthesis.
• Characterization of the (Ni,Fe)-Sx-Fe/NGr catalyst for its structural and electronic properties.
• Electrochemical testing in a water splitting device to evaluate performance.

Main Results:

• The (Ni,Fe)-Sx-Fe/NGr catalyst exhibited lower overpotentials for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) compared to NiFeSx and NiFe LDH.
• Achieved significantly improved performance over most reported electrode materials at 10 mA/cm².
• Demonstrated excellent geometric and chemical stability over 210 hours of testing.
• As a dual-functional electrode for overall water splitting, it showed a lower driving voltage (1.44 V) and stability for 110 hours at 10 mA/cm².

Conclusions:

• The developed bimetallic sulfide coupled nitrogen-doped graphene ((Ni,Fe)-Sx-Fe/NGr) offers notable activity and stability for water splitting.
• This catalyst serves as a valuable reference for the industrial production of green hydrogen.
• Highlights the potential of engineered non-precious metal catalysts for sustainable energy solutions.