Enhancing Oxygen Evolution Reaction Performance with rGO/CoNi-Prussian Blue-Derived Oxyhydroxide Nanocomposite...

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy Technologies

Background:

• Electrochemical water splitting is crucial for renewable energy, but relies on expensive precious metals.
• Developing cost-effective and efficient catalysts is essential for widespread adoption.

Purpose of the Study:

• To synthesize a novel reduced graphene oxide and cobalt-nickel hexacyanoferrate (rGO/CoNiHCF)-derived composite (rGO/CoNiPBd-OOH) for optimized oxygen evolution reaction (OER) performance.
• To investigate an "all-electrochemical" synthesis strategy for advanced electrocatalyst materials.

Main Methods:

• Fabrication of rGO/CoNiHCF using a Co:Ni precursor ratio of 3:1 and ferricyanide solution at pH 1.0.
• Alkaline electrochemical treatment to convert CoNiHCF on rGO into metallic (oxy)hydroxide frameworks.
• Electrocatalytic performance testing for OER, including Tafel slope and overpotential measurements, and stability tests.

Main Results:

• The synthesized rGO/CoNiPBd-OOH nanocomposite exhibited a superior Tafel slope of 33 mV dec⁻¹.
• Achieved an overpotential of 346 mV at 10 mA cm⁻², with remarkable stability maintaining current for 15 hours.
• Demonstrated significantly better kinetic activity and stability compared to individual components and benchmark RuO₂.

Conclusions:

• The "all-electrochemical" synthesis provides an effective route to produce advanced electrocatalysts for OER.
• The developed rGO/CoNiPBd-OOH material offers a promising, stable, and efficient alternative to precious metal catalysts for water splitting.
• Understanding synthetic parameter influence is key to optimizing electrocatalyst performance.