Amorphous nickel tungstate films prepared by SILAR method for electrocatalytic oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Efficient electrocatalysts are crucial for hydrogen energy production via water electrolysis.
• Non-noble metal-based catalysts are highly sought after as alternatives to precious metals.
• Nickel-based materials show promise for oxygen evolution reactions in alkaline media.

Purpose of the Study:

• To synthesize amorphous nickel tungstate (NiWO4) using a facile method.
• To evaluate the electrocatalytic performance of NiWO4 for the oxygen evolution reaction (OER) in alkaline conditions.
• To assess the long-term stability of the developed electrocatalyst.

Main Methods:

• Successive ionic layer adsorption and reaction (SILAR) method for NiWO4 synthesis.
• Comprehensive characterization using XRD, Raman, FTIR, SEM, XPS, and TEM.
• Electrochemical analysis including overpotential, Tafel slope, and chronopotentiometry measurements.

Main Results:

• Amorphous NiWO4 films were successfully synthesized and characterized.
• The NiWO4 electrocatalyst exhibited an overpotential of 315 mV at 100 mA cm-2 with a low Tafel slope of 32 mV dec-1 for OER.
• The catalyst demonstrated excellent stability, retaining 97% of its OER activity after 24 hours of operation.

Conclusions:

• Facile synthesis of amorphous NiWO4 provides a promising non-noble metal electrocatalyst for water electrolysis.
• The developed NiWO4 material is highly efficient and stable for oxygen evolution reactions in alkaline media.
• This work contributes to the advancement of cost-effective hydrogen production technologies.