Functionalized ordered mesoporous carbon for the adsorption of reactive dyes

摘要

A novel ordered mesoporous carbon containing basic nitrogen functional groups was synthesized by ammonia-tailoring at a temperature of 1173 K and was applied for reactive dye adsorption. The basic nitrogen-containing functional groups incorporated into the carbon surface could enhance the dispersive interactions between the carbon and dye molecules due to the electron-donating . effect as well as the electrostatic interactions between the carbon surface and the anions of the dyes. It was found that this novel functionalized ordered mesoporous carbon could increase the adsorption capacity of reactive red 2 at 298 K by around 40 % and 100 % as compared with the unmodified carbon and a commercial activated carbon, respectively. The Freundlich isotherm showed better correlation with the experimental adsorption data of ammonia-tailored samples than the Langmuir isotherm due to the increased surface heterogeneity induced by the nitrogen-containing functional groups. Adsorption of reactive red 2 was an endothermic process as the adsorption capacity increased with increasing temperature. Low desorption efficiency revealed that the adsorption of reactive red 2 on the modified CMK-3 was extremely favorable, tending to be weakly reversible.