Synergistic TiO₂ Nanosheets and Nitrogen-doped Carbon-coated NiCo₂O₄ Nanocomposite for High-performance Hybrid Supercapacitors
J. Environ. Nanotechnol., Volume 15, No 1 (March 2026) pp. 249-261
Abstract
With the growing demand for high-performance energy storage devices, the development of electrode materials with high conductivity, large surface area, and long cycling stability is crucial. Nickel cobaltite coated with nitrogen-doped carbon nanoparticles (NiCo₂O₄@N-C) and its TiO₂-integrated nanocomposite (NiCo₂O₄@N-C/TiO₂) were successfully synthesized using a combined chemical route and ultrasonication technique. The novelty of this work lies in the synergistic integration of carbon-coated NiCo₂O₄ with conductive TiO₂ nanosheets, which suppresses nanoparticle agglomeration and enhances charge-transfer pathways. The nanocomposite exhibited improved electrical conductivity (1.9 × 10⁻³ S/m) compared to its pristine counterpart due to the interconnected conductive network formed by the TiO₂ nanosheets and the nitrogen-doped carbon coating. The enlarged effective surface area and improved electrolyte accessibility resulted in a high gravimetric capacitance of 709 F/g at 1 A/g, with 80% capacitance retention after 10³ charge–discharge cycles. Electrochemical impedance spectroscopy revealed a low charge-transfer resistance (~20 Ω), indicating accelerated redox kinetics and enhanced pseudocapacitive behavior. The dual role of TiO₂ nanosheets as both a capacitive contributor and a conductive matrix plays a key role in boosting electrochemical performance. These findings demonstrate that the NiCo₂O₄@N-C/TiO₂ nanocomposite is a promising electrode material for high-performance hybrid supercapacitor applications.
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Reference
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