Convenient preparation of nitrogen-doped activated carbon from Macadamia nutshell and its application in supercapacitor

Nitrogen-doped activated carbon has been successfully prepared via a convenient buried-type chemical activation technology, by using Macadamia nutshell as carbon source, melamine as nitrogen source and KOH as activating agent. The nitrogen-doped activated carbon product is used as electrode material for the application of supercapacitor. The material structures and surface morphologies are studied by XRD, SEM and TEM techniques. The electrochemical properties are investigated by CV, constant current CDC and AC impedance methods. The results showed that after activation procedure the nitrogen-doped activated carbon have a high specific surface area (1615 m2 g−1) and moderate nitrogen content (6.83%). The nitrogen-doped activated carbon electrode exhibits good capacitance performances in 1 mol L−1 KOH aqueous electrolyte. At a current density of 1 A g−1, the specific capacitance of the nitrogen-doped activated carbon electrode is 229.7 F g−1, which is much higher than that (98.4 F g−1) of nitrogen-free activated carbon electrode.