Lanthanum-Doped Co₃O₄ Nanocubes Synthesized via Hydrothermal Method for High-Performance Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors require high-performance electrodes for efficient energy storage.
• Cobalt oxide (Co₃O₄) offers high theoretical capacitance but suffers from poor conductivity and instability.
• Lanthanum (La³⁺) doping is explored to overcome these limitations in Co₃O₄.

Purpose of the Study:

• To synthesize and characterize La³⁺-doped Co₃O₄ nanocubes.
• To investigate the effect of varying La³⁺ doping concentrations on structural and electrochemical properties.
• To evaluate the potential of La³⁺-doped Co₃O₄ as a supercapacitor electrode material.

Main Methods:

• Hydrothermal synthesis of La³⁺-doped Co₃O₄ nanocubes with varying doping levels (1%, 3%, 5%).
• Structural characterization using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission Electron Microscopy (TEM).
• Electrochemical performance evaluation in a 3 M KOH electrolyte, including specific capacitance, capacitance retention, and Coulombic efficiency.

Main Results:

• Successful synthesis of cubic spinel Co₃O₄ structures with incorporated La³⁺.
• 1% La³⁺-doped Co₃O₄ exhibited optimal electrochemical performance.
• Achieved specific capacitance of 1312 F g^-1 at 1 A g^-1.
• Demonstrated excellent cycling stability with 79.8% capacitance retention over 10,000 cycles at 5 A g^-1.
• High Coulombic efficiency of 97.12% was recorded.

Conclusions:

• La³⁺ doping is an effective strategy to enhance the electrochemical performance of Co₃O₄-based supercapacitor electrodes.
• Doping improves charge storage capability and cycling stability.
• La³⁺-doped Co₃O₄ nanocubes show promise for next-generation energy storage applications.