2. Materials and methods
The viscous sugarcane molasses fluid was dried at 130 ◦C for
48 h, and the precursor was ground by ball milling to a powder.
The powdered molasses was mixed with the saturated KOH solution
according to a KOH:M mass ratio from 2.8:1 to 0.7:1, and the
soaking time was equal to 3 h. The carbonization in the presence of a
chemical activating agent was performed in a vertical tube furnace
with 40 mm diameter and a nitrogen flow of 18 dm3 min−1 using
a heating rate of 10 ◦C min−1. The temperature of the carbonization
ranged from 400 to 800 ◦C to prepare the series of ACs, and
the time of carbonization was equal to 1 h. The carbonized samples
were repeatedly washed with water. Subsequent to this, a 5 M solution
of HCl was used to remove the activating agent, followed by
distilled water rinsings until free of chloride ions. The presence of
chloride ions was verified by silver nitrate solution. Consequently,
the samples were dried at 110 ◦C for 12 h.