Effect of an activating agent on the physicochemical properties and supercapacitor performance of naturally nitrogen-enriched carbon derived from Albizia procera leaves

Abstract

The present study reports the preparation of naturally nitrogen-doped carbon nanostructured materials from Albizia procera leaves with enhanced electrochemical supercapacitance properties. The doped carbon materials were prepared by the pyrolysis of Albizia procera leaves at 850 °C. The effect of using various activating agents such as NaHCO3 and ZnCl2 was checked and compared on the structural and textural properties, specific capacitance, surface functional groups, and surface area. The Brunauer–Emmett–Teller(BET) analysis shows that NaHCO3-activated nitrogen-doped carbon (NaNC) has a higher specific surface area compare to ZnCl2-activated nitrogen-doped carbon (ZnNC) and nitrogen-doped carbon prepared without an activating agent (WANC). Overall, the BET and microscopic analyses confirmed that NaNC is composed of carbon nanosheets with macropores and mesopores, as well as a large number of micropores, which is completely different from the composition of ZnNC and WANC. In addition, the XPS analysis confirmed the existence of higher amount of nitrogen in NaNC compared to that of ZnNC, and WANC. NaNC exhibits a specific capacitance of 231 F g−1 at 1 A g−1 current with good energy and power densities, and an outstanding charging-discharging stability thanks to its unique features such as the existence of high amounts of nitrogen, high SSA, and the nanosheet-type morphology.