Facile synthesis of hierarchical morphology highly porous carbon cobalt oxide composite from one-step carbonization of bio-waste for energy storage application

A new strategy made to have a low-cost highly porous carbon electrode material by using bio-waste date seeds is activated with potassium hydroxide (KOH) for the synthesis of porous carbon cobalt oxide composite (PCCo) by facile one-step carbonization, and achieved high specific capacitance. The characterization of PCCo composite was done by powder X-ray diffraction, Fourier transform infrared spectrometer, field emission scanning electron microscopy, high-resolution transmission microscopy, and Raman spectroscopy techniques to confirm the changes in the chemical formation of the composite. The obtained PCCo composite has a porous structure with carbon frameworks and uniformly dispersed Co ₃ O ₄ nanoparticles. This hierarchical architecture offers good ion/electron transport channels for better electrochemical characteristics.The maximum specific capacitance was found to be 548.4 F/g at a scan rate of 10 mV/s, and also from the galvanostatic charge-discharge curve, it was 696.8 F/g at a current density of 1.5 A/g. Additionally, capacitance retention is 84.4% and coulombic efficiency is 97% even after 5000 cycles. The energy density is 47.4 Wh kg ^-1 and the power density is 853.2 W kg ^-1 . These results suggest that porous carbon composites are cost-effective, technologically unique, and eco-friendly for environmental supercapacitor applications.