The results showed that the nitrogen adsorption analyses for
Brunauer–Emmett–Teller (BET) specific surface area (m2
/g), as well as
total pore volume (cm3
/g) and the micropore volume decrease with
the addition of HNO3. The textural characteristics of samples are summarized
in Table 2. The results showed that the ratio of the microporous
surface to the total surface area (Smicro/SBET) varies from 42% to 79% for
oxidized activated carbons and varies from 53% to 81% for activated carbons.
A large micropore volume and total pore volume are obtained
(0.170 and 0.326 cm3
/g, respectively for the NBZCOX)