Surface Functionalization and Pore Size Manipulation for Carbons of Ordered Structure

Covalent functionalization and pore size manipulation were successfully achieved on ordered mesoporous carbons, by using a method in which diazonium compounds were in-situ generated and reacted with the carbon surface. Aryl groups substituted on the 4-poisiton (Ar−R, R = chlorine, ester, and alkyl) were covalently attached to the surface of hexagonally structured carbon, which was synthesized using ordered silica SBA-15 as template. The presence of these functional groups on the modified carbons was confirmed with Fourier transform infrared spectroscopy, thermogravimetric analysis, electron microscopy, and nitrogen adsorption. A relatively high grafting density of ∼1.5 μmol/m 2 was achieved. Chemical modification considerably changed the pore width from 3.0 nm for the unmodified samples to ∼1.4 nm for modified samples, while the primary hexagonal structure and the unit parameter of ordered mesoporous carbon were retained after attachment of surface functionalities.