Complex insight into the charge storage behavior of active carbons obtained by carbonization of the plane tree seed

Activated carbon was prepared using plane tree seed as a cheap and renewable raw material. The samples were prepared by carbonization under N2 atmosphere up to 850 °C, and activation in CO2 atmosphere at different both temperatures (750 and 850 °C) and times of activation (0.3, 1 and 2 h). The influence of activation parameters on physicochemical properties was studied by XRPD, Raman spectroscopy, FTIR, N2 physisorption, SEM and electrochemical methods. The pore structure was correlated to the specific capacitance and the amount of hydrogen stored, in alkaline, neutral and acidic electrolyte solution. The relationship of asymmetrical shape of CV curves with the porosity of samples has served to better understand some unclear issues related to the complex mechanism of charge storage. The sample activated at 850 °C for 2 h displayed the best behavior. At a high scan rate of 300 mV s−1, its capacitance, amounted to ∼26.8 μF cm−2 ∼19.69 μF cm−2 and ∼25.8 μF cm−2 in KOH, Na2SO4, and H2SO4 solutions, respectively.