Supporting Information
Grafting and stabilization of ordered mesoporous silica COK-12
with graphene oxide for enhanced removal of methylene blue
Laura M. Henninga*, Ulla Simona, Aleksander Gurloa, Glen J. Smalesb, and Maged F. Bekheeta
a Fachgebiet Keramische Werkstoffe / Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien,
Fakultät III, Technische Universität Berlin, Hardenbergstr. 40, 10623 Berlin, Germany
b Bundesanstalt für Materialforschung und -prüfung (BAM), Division 6.5 – Polymers in Life Sciences and Nanotechnology, Unter den Eichen
87, 12205 Berlin, Germany
* corresponding author. Contact details: e-mail address: [email protected], telephone: +49 (0) 30 314 25202
𝐴𝑟𝑒𝑎 𝑜𝑓 𝐴𝐵𝐶 𝑒𝑞𝑢𝑖𝑙𝑎𝑡𝑒𝑟𝑎𝑙 𝑡𝑟𝑖𝑎𝑛𝑔𝑙𝑒 =
𝑎2
03
4
𝑊𝑎𝑙𝑙 𝑎𝑟𝑒𝑎 𝑖𝑛 𝐴𝐵𝐶 𝑡𝑟𝑖𝑎𝑛𝑔𝑙𝑒 =
𝑎2
03
4‒𝜋𝐷2
8
Figure S1. Schematic drawing of the hexagonal pore structure of COK-12 and the corresponding calculation for
the wall area.
Electronic Supplementary Material (ESI) for RSC Advances.
This journal is © The Royal Society of Chemistry 2019
Figure S2. SEM images of GO-grafted COK-12-GO-2*.
Figure S3. Raman spectra of GO, pure COK-12, and GO grafted COK-12-GO with low (-1), medium (-2) and
high (-3) GO concentration. The asterisk (*) represents the upscaling.
Figure S4. Zeta potentials of GO, pure COK-12, and GO grafted COK-12-GO-2*.
Figure S5. Removal efficiency (bar) and Si content (black square) of the supernatant after adsorption of MB on
pure COK-12 and grafted COK-12-GO samples with 4 wt% (-1), 50 wt% (-2), and 60 wt% (-3) GO. Adsorption
conditions were 2 g l-1, 100 mg l-1 MB, pH 5.65, 180 min.
Figure S6. Nonlinear pseudo-second order kinetics fitting for the adsorption of MB on COK12-65-500, which is
COK-12 but aged at 65 °C. Adsorption conditions were pH = 5.65, dosage = 2 g l-1, and MB = 100 mg l-1.
𝐶𝑖
Table S1. Parameters of the isotherm studies according to the Langmuir and Freundlich models depicted in
Figure 10 for pure COK-12 and the GO grafted COK-12-GO-2*.
Model
Parameter
COK-12
COK-12-GO-2*
Langmuir
(mg g-1)
𝑞𝑚
20.2
197.5
(l mg-1)
𝐾𝐿
2.97
2.09
R2
0.988
0.990
Freundlich
(mg g-1)
𝑛
9.30
8.35
(mg g-1(l mg-1 )
𝐾𝐹)1/𝑛
11.30
102.52
R2
0.961
0.970
Table S2. Parameters of the kinetic studies according to the pseudo-first order, pseudo-second order, and
Elovich model depicted in Figure 11 for pure COK-12 and GO grafted COK-12-GO-2*.
Model
Parameter
COK-12
COK-12-GO-2*
Pseudo-first order
(mg g-1)
𝑞𝑒
15.4
158.6
(min-1)
𝐾1
6.35
0.16
R2
0.9976
0.9510
Pseudo-second order
(mg g-1)
𝑞𝑒
15.4
168.2
(g mg-1 min-1)
𝐾2
1.22
1.54 × 10-3
R2
0.9981
0.9889
Elovich
α
1.25 × 1017
2449
β
2.93
0.06
R2
0.9960
0.9855
