Electrosorption of environmental concerning anions on a highly porous carbon aerogel

A high surface activated carbon aerogel has been prepared by the resorcinol–formaldehyde method. A supercritical drying process ensured the preservation of the pore structure existing in the polymerized precursor. The structural and textural properties of the carbon aerogels have been examined by X-ray diffraction, Raman and infrared spectroscopy revealing an increase of the crystallite size and the presence of surface functional groups in the activated sample. The activation process involved an increase of the micropore volume which led to an increase of the electrosorption capacitance of sodium chloride, nitrate and phosphate. Otherwise, the complex micropore structure built after the activation reaction exerts a sieve effect that enables the nitrate anions migration, while large phosphate ions are slowed down. Deionization experiments revealed an enhanced electroadsorption of NaNO3 on the activated sample.