Adam, Rashed Ali MohamedTarimo, Delvina JaphetMaphiri, Vusani MuswaMirghni, Abdulmajid AbdallahFasakin, OladepoManyala, Ncholu I.2026-02-182026-02-182025-04Adam, R.A.M., Tarimo, D.J., Maphiri, V.M. et al. 2025, 'Effects of the physisorption properties of human hair-derived activated carbon as a potential electrode for symmetric supercapacitor', Materials for Renewable and Sustainable Energy, vol. 14, no. 1, art. 22, pp. 1-17. https://doi.org/10.1007/s40243-024-00294-3.2194-1459 (print)2194-1467 (online)10.1007/s40243-024-00294-3http://hdl.handle.net/2263/108360Herein, human hair-derived activated carbon (HH-AC) with remarkable physisorption properties such as high surface area and well-balanced micro- and mesopores, is synthesized by chemical activation method using potassium hydroxide (KOH). The activated carbon is synthesized at different ratio of charred human hair and activator as 1:1, 1:2 and 1:3 for HH AC(11), HH-AC(12) and HH-AC(13), respectively. These activated materials are characterized by a powder X-ray diffraction (XRD), Laser Raman spectroscopy, Scanning electron microscope (SEM), and N2 adsorption/desorption isotherms. To examine the influence of the micro-mesopore ratio with high surface area on supercapacitor behavior, all samples are tested in a three-electrode using 2.5 moles of potassium nitrate (2.5 M KNO3) as electrolyte solution. The results show that HH-AC(12) sample which has micro to mesopore-balanced (50 : 50) exhibited superior electrochemical performance with specific capacitance of 215 F g−1 and 125.8 F g−1 in the negative and positive potential, respectively at 1A g−1. The sample HH-AC(11), which is dominated by micropores, showed lower rate capability and specific capacitance despite the huge surface area. Whereas the HH-AC(13) sample with mostly mesopores achieved higher rate capability compared to the others. The HH-AC(12) is further examined in a 2-electrode setup to form a symmetric device. The results show a specific energy of 16Wh kg−1 and a specific power of 375Wkg−1 at 0.5 A g−1. The device demonstrates outstanding capacitance retention of 97% after 10,000 cycles. Thus, ACs with micro to mesopores-balanced are potential candidates for supercapacitor applications.en© 2025 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND).SupercapacitorActivated carbonEnergy storageMicroporousMesoporousHuman hair-derived activated carbon (HH-AC)X-ray diffraction (XRD)Laser Raman spectroscopyScanning electron microscope (SEM)N2 adsorption/desorption isothermsArticle