*2.3. Characterization*

Thermal drying method is used for the determination of moisture content of the raw material. The STLs were dried at 110 ◦C until the consistency of weight was obtained. The moisture percentage in the sample was expressed as the loss in the mass due to drying as a percentage of the total mass of the sample.

Elemental analysis of the precursor and activated carbons was carried out in a CHNS Analyzer. Prior to analysis, the samples were dried overnight at 105 ◦C and cooled in desiccators. Oxygen content was obtained by the difference between the total percentage (100 wt.%) and the sum of percentages (wt.% dry ash-free) of nitrogen, carbon, hydrogen, and sulfur.

The textural properties of the prepared samples were assessed by nitrogen adsorption– desorption measurements at −196 ◦C using a Quantachrome Autosorb-6 apparatus. The materials were previously degassed at 250 ◦C for 4 h. The surface area (SBET) was calculated from isotherms using the Brunauer–Emmett–Teller (BET) equation [50]. The volume of liquid nitrogen corresponding to the amount adsorbed at a relative pressure of P/P<sup>0</sup> = 0.99 was defined as total pore volume (VT). The micropore volume (Vµp) was determined from Dubinin–Radushkevich equation [51].
