Preparation and electrochemical characterization of carbon materials from Pinus radiata bark

Pinus radiata bark (PB), a waste product of one of the most widely cultivated tree species, has huge potential as a promising renewable carbon source for supercapacitor electrodes due to its high carbon and polyphenolic contents. In this study, PB was directly carbonized from 600 to 900 °C to investigate its performance as an electrode material in supercapacitor applications. The resulting carbonized pine barks (cPBs) consisted of more than 90% carbon and were predominantly amorphous, with abundant active functional groups, as confirmed by Infrared, Raman, and X-ray diffraction spectroscopy. The cPBs exhibited a well-developed pore structure consisting of micropores and mesopores, with specific surface areas ranging from 408 to 528 m²/g. The CV curves for cPBs showed a distorted oval shape, indicating characteristics of capacitive behavior. Notably, the carbonized bark at 700 °C demonstrated the highest specific capacitance of 73 F/g at 0.3 A/g, with good cycling stability of 109% after 5000 cycles. Hence, these results demonstrate that direct carbonization of PB biomass waste, without any additional activation step, offers a sustainable and cost-effective alternative for producing carbon electrode materials for supercapacitors.