area analyzer (Micromeritics ASAP 2020). Iodine number of the activated
carbon was determined using the sodium thiosulfate volumetric
method [25]. In order to determine quantitatively and qualitatively surface
functional groups of the activated carbon, Boehm's titrationmethod
[24] and FT-IR analysis were applied, respectively. pHzpc value of the
carbon was measured by using Malvern Nanosize ZS-3600 zetasizer. A
scanning electron microscope was used to examine the surface morphology
of the grape stalk and activated carbons obtained. The samples
for SEManalysiswere prepared by sputter-coating the surfaceswith Au.
The elemental composition was analyzed by EDX. Particle size distribution
and elemental analysis of the samples were performed using
Malvern Master Sizer 3000 and LECO CHNS 932 Elemental Analyzer,
respectively.