Nature inspired approach to mimic design for increased specific capacitance as supercapacitor electrodes

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Citrus fruit peels are abundant waste materials.
• Activated carbon is a key material for supercapacitors.
• Incorporating heteroatoms like nitrogen can improve electrochemical properties.

Purpose of the Study:

• To investigate the use of orange peels (OP) and lemon peels (LP) as a carbon source for supercapacitor materials.
• To introduce nitrogen heteroatoms by naturally doping peels with bacteria (Escherichia coli, E. coli).
• To evaluate the electrochemical performance of bacteria-doped activated carbon derived from citrus peels.

Main Methods:

• Utilizing discarded orange peels (OP) and lemon peels (LP) as carbon sources.
• Naturally doping the peels with Escherichia coli (E. coli) to introduce nitrogen heteroatoms.
• Preparing bacteria-doped activated carbon and characterizing its surface and electrochemical properties.

Main Results:

• Bacteria-doped activated carbon showed increased nitrogen content and improved surface properties.
• Specific capacitance significantly increased: 92.4 Fg⁻¹ (OP) and 139 Fg⁻¹ (LP) compared to bare samples (60.9 Fg⁻¹ and 49.6 Fg⁻¹).
• Excellent capacity retention of 129% after 10,000 cycles was observed for bacteria-doped samples.

Conclusions:

• Discarded citrus peels can be effectively converted into high-performance supercapacitor materials using a simple, cost-effective, and eco-friendly bacterial doping method.
• This approach offers a sustainable pathway for waste valorization and the fabrication of advanced energy storage devices.