JCIS 421-2014-93

Influence of multi-walled carbon nanotubes on textural and adsorption
characteristics of in situ synthesized mesostructured silica

Carbon nanotubes–mesostructured silica nanoparticles (CNT–MSN) composites were prepared by a
simple one step method with various loading of CNT. Their surface properties were characterized by
XRD, N2 physisorption, TEM and FTIR, while the adsorption performance of the CNT–MSN composites
were evaluated on the adsorption of methylene blue (MB) while varying the pH, adsorbent dosage, initial
MB concentration, and temperature. The CNTs were found to improve the physicochemical properties of
the MSN and led to an enhanced adsorptivity for MB. N2 physisorption measurements revealed the
development of a bimodal pore structure that increased the pore size, pore volume and surface area.
Accordingly, 0.05 g L1 CNT–MSN was able to adsorb 524 mg g1 (qm) of 60mg L1 MB at pH 8 and
303 K. The equilibrium data were evaluated using the Langmuir, Freundlich, Temkin, and Dubinin-
Radushkevich isotherm models, with the Langmuir model affording the best fit to the adsorption data.
The adsorption kinetics were best described by the pseudo-first order model. These results indicate
the potential of CNT–MSN composites as effective new adsorbents for dye adsorption.