FTIR analysis results of sour cherry stones and activated carbon
are given in Supplementary Fig. S2. The mentioned in figure, while
the bands about 1985–2462 cm1 which were generally attributed
to symmetric or asymmetric stretching of aliphatic band in –CH,
–CH2 or –CH3 were observed as much stronger at produced activated
carbons, they were not seen in the FTIR spectrum of the sour
cherry stones. The aliphatic functional groups were formed, possibly
due to the extraction of H element and OH groups from the aromatic
rings during the impregnation and heat treatment stages as a
result of the dehydration effect of ZnCl2 (Angın et al., 2013b). The
bands about 1020.34 cm1 show the C–O–C stretching (alcohols,
ethers or phenols) and O–H deformation vibrations (Foo and
Hameed, 2011). These bands decreased by activation process as
compared to the raw material. These results indicated that the carbonyl
groups and substitution in aromatic rings were affected by
thermal effect (Angin, 2014).