Preparation of carbon sphere-activated carbon composite materials from microcrystalline cellulose via hydrothermal carbonization

Carbon sphere-activated carbon composite materials with abundant oxygen functional groups were prepared from microcrystalline celluloses(MC) via hydrothermal carbonization by using citric acid as catalyst and activated carbons as carrier. The morphology structure, pore structure, and the species of oxygen-containing functional groups of composite materials were analyzed by SEM, N2(77K) adsorption-desorption isotherm, and FT-IR. Adsorption capacity of the materials were tested using aqueous solution (Cr3+) as model metal ions. The results showed that MC could be transformed into carbon spheres, which are loaded on the surface and interior of activated carbon. The size and quantity of the carbon spheres of the obtained composites were influenced by the carbonization parameters, such as temperature, reaction time and the concentration of the MC. Surface functional groups, including hydroxyl, carbonyl and carboxyl, were observed on the surface of the prepared composites. The carbon sphere-activated carbon composite materials presented extraordinary adsorption capacities for Cr3+ in terms of per mass, which was 0. 356 mg/g. This result is approximately 5.65 times of that for activated carbon. ©, 2015, Editorial Board of Chemistry and Industry of Forest Products. All right reserved.