In this work, mesoporous carbon with impregnated iron oxide nanoparticles has been synthesized by the colloidal-imprinting and iron nitrate decomposition processes. First, silica-sucrose composite material was synthesized by dispersing colloid silica into a sucrose solution, forming a composite structure of well-dispersed silica nanoparticles in sucrose matrix. Secondly, the sucrose was carbonized at 550„aC in N2 atmosphere. Finally, the dispersed silica nanoparticles were removed by chemical dissolution to form a mesoporous structure. The silica/sucrose ratio was varied to form a stable, 3-dimentional, and ordered mesopore structure. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), micropore surface analyzer (BET), and electron microscopy were deployed for material characterization. The mesoporous carbon synthesized at sucrose/silica ratio of 0.8 has a bimodal pore structure with large pores at 2ƒÝm and uniform mesopores at ~19.9 nm. The surface area of the mesoporous carbon varies from 672 to 1276.2 m2/g as sucrose/silica ratio declines from 2.4 to 0.8. The mesoporous carbon was further treated by pore filling and decomposition of iron nitrate to form a mesoporous carbon with encapsulated iron oxide nanoparticles.
The removal of As(V) from aqueous solution at different concentrations and adsorption kinetics were investigated by bulk adsorption experiments. Laboratory adsorption experiments indicated that the adsorption reach equilibrium within 1.5 hr and can be best fitted by Feundlich model. The high adsorption capacity and fast kinetics suggest that the mesoporous carbon with encapsulated iron oxides show promising application in heavy metal removal from water.