Highly efficient oxygen evolution from CoS₂/CNT nanocomposites via a one-step electrochemical deposition and...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Conversion

Background:

• The oxygen evolution reaction (OER) is crucial for electrochemical energy devices.
• Developing cost-effective and efficient OER electrocatalysts is an ongoing challenge.
• Existing catalysts often rely on expensive noble metals.

Purpose of the Study:

• To develop a new, efficient, and cost-effective electrocatalyst for the oxygen evolution reaction.
• To fabricate hydrophilic porous cobalt disulfide/carbon nanotube (CoS2/CNT) composites using a facile electrochemical method.
• To investigate the structural and electrochemical properties of the synthesized CNT-CoS2 material.

Main Methods:

• A one-step electrochemical deposition and dissolution method was employed to synthesize CNT-CoS2 composites.
• X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy were used for surface characterization.
• Electrochemical performance was evaluated through OER activity, onset potential, current density, and stability tests in alkaline media.

Main Results:

• The synthesis successfully produced hydrophilic porous CoS2/CNT composites with enhanced conductivity and surface area.
• The CNT-CoS2 catalyst exhibited a low onset potential of 1.33 V vs. RHE and achieved 10 mA cm-2 at an overpotential of 290 mV.
• The catalyst demonstrated excellent stability in alkaline conditions, outperforming commercial IrO2.

Conclusions:

• The developed CNT-CoS2 composite is a highly efficient and stable noble metal-free electrocatalyst for the oxygen evolution reaction.
• The combination of porous nanostructures, enhanced conductivity, and hydrophilic surface groups significantly boosts catalytic performance.
• The facile electrochemical synthesis strategy is suitable for large-scale production for applications like water electrolysis.