Nanostructurally engineered TiO₂ embedded Mentha aquatica biowaste derived carbon for supercapacitor applications

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing cost-effective, clean, and eco-friendly energy storage is a global priority.
• Biogenic synthesis offers a sustainable approach to nanomaterial production.
• Utilizing waste materials in synthesis reduces environmental impact.

Purpose of the Study:

• To develop a novel, environmentally benign composite material for supercapacitor applications.
• To investigate the electrochemical performance of biogenically synthesized TiO2 nanoparticles coupled with biomass-derived activated carbon.
• To demonstrate a waste-valorization strategy for energy storage materials.

Main Methods:

• Biogenic synthesis of TiO2 nanoparticles using Mentha Aquatica leaf extract.
• Preparation of biomass-derived activated carbon (BAC) from residual solid waste.
• Ultrasonic coupling of TiO2 nanoparticles and BAC to form the TiO2@BAC composite.
• Electrochemical characterization of supercapacitor electrodes using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

Main Results:

• The TiO2@BAC composite exhibited a specific capacitance of 149 F/g, nearly double that of bare TiO2 (76 F/g).
• The composite demonstrated excellent capacitance retention of ~99% and outstanding cyclic stability with ~90% retention after 10,000 cycles at 5 A/g.
• The TiO2@BAC electrode achieved high energy density (6.96 Wh/kg) and power density (2.07 kW/kg).
• High coulombic efficiency (~98%) and excellent retention (~95%) were observed in a symmetric configuration.

Conclusions:

• The developed TiO2@BAC composite is a promising, sustainable material for high-performance supercapacitors.
• The green synthesis method avoids toxic chemicals and secondary waste generation.
• This approach highlights the potential of combining biogenic synthesis and waste valorization for advanced energy storage solutions.