In this work, highly porous carbons were prepared by chemical activation of carbonized
biomass-derived aerogels. These aerogels were synthesized from watermelon flesh using a
hydrothermal reaction. After carbonization, chemical activation was conducted using potassium
hydroxide to enhance the specific surface area and microporosity. The micro-structural
properties and morphologies were measured by X-ray diffraction and scanning electron microscopy,
respectively. The specific surface area and microporosity were investigated by
N2/77 K adsorption-desorption isotherms using the Brunauer-Emmett-Teller method and
Barrett-Joyner-Halenda equation, respectively. Hydrogen storage capacity was dependent on
the activation temperature. The highest capacity of 2.7 wt% at 77 K and 1 bar was obtained
with an activation temperature of 900°C.