Sycamore fallen leaves-derived porous carbon for high-performance supercapacitor electrodes

Every year, an enormous number of leaves drop throughout the fall and winter months. The disposal of autumn leaves through landfill or incineration poses a significant environmental burden and represents a substantial underutilization of resources. In parallel, the development of low-cost, high-performance electrode materials remains a critical challenge in the field of supercapacitors. This study demonstrates an innovative approach to converting waste sycamore leaves into highly efficient porous carbon for supercapacitor electrodes via KOH activation. The resulting carbon material, synthesized at 800 ℃ exhibits a high specific surface area (843.58 m² g^{− 1}), a substantial pore volume (0.531 cm³ g^{− 1}), and beneficial co-doping with N (1.58 at%), O (28.13 at%), and P (0.41 at%) heteroatoms. These structural merits contribute to outstanding electrochemical performance, achieving a specific capacitance of 255.2 F g^{− 1} at 1 A g^{− 1} in a three-electrode system with 3 M KOH. Furthermore, the assembled supercapacitor device delivers high power and energy densities, making it a promising candidate for practical applications.