Characterization of adsorbents
The ZnCl2 activated SSH carbons generally displays irregular
particles with sizes ranging from sub-micrometers to a few or tens
of micrometers depending on the degree of hand grinding, as
shown in Fig. 1(a). However, looking closely to the micrometersized
particles (Fig. 1(b)), we may clearly see some nanoporous
structures, which might have contributed to the high surface area
and large pore volume of the ZnCl2 activated SSH carbons, as will
be discussed later. The XRD patterns of the four carbon samples are
shown in Fig. 1(c), which characterize the amorphous nature of the
obtained activated carbons, as the temperatures used for
activations were still too low to graphitize the pyrolized SSH.
The FTIR spectra of the corresponding samples as shown in Fig.1(d)
are used to evaluate the surface chemistry of the activated carbons.
All samples show similar FTIR spectra that include a broad
adsorption band at about 3419–3440 cm1 due to the stretching
vibrations of
OH hydroxyl groups and bands at 1619–1634,
1388 and 1100–1141 cm1 due to skeleton vibration of aromatic
C¼C, the in-plane bending vibration of OH, and the CO
stretching vibrations of alcoholic, phenolic and carboxylic groups
or bridge bonds, respectively