Catalytic deposition of nanocarbon onto palygorskite and its adsorption of phenol

A novel palygorskite/carbon sorbent was synthesized by hydrothermal carbonization of glucose onto palygorskite using ammonium ferrous iron (Fe(2+)) sulphate hexahydrate as catalyst under mild conditions. The resulting palygorskite/carbon nanocomposites were characterized by field-emission scanning electron microscopy, X-ray diffraction patterns, Fourier transform infrared spectroscopy and total carbon content analysis. It was found that the nano-carbon with diameter of 30-50 nm was successfully loaded onto the palygorskites crystal surfaces, accompanied by abundant C H groups. The mechanism of formation of nanocomposites was proposed as follows. Two carbonization routes of glucose coexisted, namely random carbonization and adsorption-induced carbonization on palygorskite surfaces. The formation of palygorskite/carbon was determined by competition of the two carbonization routes which could be controlled by hydrothermal conditions, i.e. reaction time, temperature and catalyst. The resultant modified palygorskite demonstrated a substantially high adsorption capacity for phenol in comparison with unmodified palygorskite. (C) 2011 Elsevier B.V. All rights reserved.