Adsorption Characteristics of Phenol and Reactive Dyes from Aqueous Solution onto Ordered Mesoporous Carbons Prepared via a Template Synthesis Route

Abstract

Ordered mesoporous carbons (OMCs) were prepared using SBA-15 as the template and sucrose as the precursor. Various different mesoporous materials (CMK-3-80, CMK-3-90, CMK-3-100 and CMK-Na 2 SiO 3 -3-90) were synthesized employing different conditions. The pore structures and characteristics of the OMC materials were evaluated using XRD, SEM and nitrogen adsorption studies, respectively, and their adsorption properties towards phenol and dyes were investigated. The results showed that the order of the pore diameter in the mesoporous materials followed the sequence: CMK-3-100 > CMK-3-90 > CMK-3-80 > CMK-Na 2 SiO 3 -3-90. Adsorption experiments revealed that the mesoporous carbons prepared possessed larger adsorption capacities towards phenol and the Reactive dyes Methylene Blue (MB) and Rhodamine Blue (RB) relative to commercial active carbon. Adsorption kinetics experiments showed that the rates of adsorption of MB and RB onto CMK-3 differed in line with the difference in pore size. Furthermore, the adsorption kinetics of MB and RB onto CMK-3 could be well described by the pseudo-first-order kinetic model. The adsorption isotherms indicated that the equilibrium adsorption capacities of the two dyes onto CMK-3 were not the same and could not be correlated with either the relative magnitudes of the mesopore surface areas or the mesopore volumes.