One-step strategy of 3D hierarchical porous carbon with self-heteroatom-doped derived bread waste for high-performance supercapacitor

Bio-waste is a promising carbon source that can be used as a basic component in renewable supercapacitors due to its abundant hierarchical pore structure potential, heteroatom self-doping capability, high surface area, as well as well-defined chemical and mechanical stability. This study converted bread bio-waste into rich 3D hierarchical porous carbon through a one-step facile strategy to be used as the main component of a supercapacitor. The porous carbon was obtained through physical activation approach at different temperatures of 750, 800, 850, and 900 degrees C without being combined with chemical activation. The optimized activated carbon illustrated high porosity behavior with an abundant 3D hierarchical pore structure consisting of 76.98% micropores and 23.02% mesopores and also produced a well-defined wettability of self-doping heteroatoms. Moreover, the electro-chemical behavior in a symmetric supercapacitor cell showed a high specific capacitance of 202 F g-1 at 1 A g-1 with a rate capability of 73% at 10 mV s-1 in a 1 M H2SO4 electrolyte. It was also discovered that the activation temperature of 850 produced the highest energy density of 11.61 Wh kg- 1 at a power density of 156.71 W kg- 1 with a low equivalent series resistance of 0.11 omega. Finally, the proof-of-concept showed that bread waste has immense potential as a 3D hierarchical porous carbon source after the synthesis through a single-stage facile approach and can be used as a major renewable electrode component for sustainable supercapacitors.

Automated summary

This study converted bread bio-waste into 3D hierarchical porous carbon through a simple method and utilized it as the main component of a supercapacitor. The optimized porous carbon exhibited high porosity with 76.98% micropores and 23.02% mesopores, as well as well-defined wettability of self-doping heteroatoms. The electrochemical behavior in a symmetric supercapacitor cell showed high specific capacitance and rate capability, while the activation temperature of 850°C resulted in the highest energy density and low equivalent series resistance.