Adsorption performance of carboxylated multi-wall carbon nanotube–Fe3O4 magnetic hybrids for Cu(II) in water

Abstract

Carboxylated multi-wall carbon nanotube( c-MWCNT)-Fe3O4 magnetic hybrids( c-MWCNTMCs) were prepared by mixing FeCl3·6H2 O,sodium acetate,ethylene glycol and diethylene glycol with c-MWCNTs,followed by sonicating and heat treatment at 200 ℃ for 10 h. Results indicated that the c-MWCNTMCs showed a good dispersion stability,an acid and alkali resistivity,and magnetic properties in deionized water,and can be used as adsorbents for Cu( Ⅱ) removal. The c-MWCNTMCs could be easily separated from water by a magnet and showed a high adsorption capacity for Cu( Ⅱ). The adsorption of Cu( Ⅱ) on the c-MWCNTMCs was quick and followed a pseudo-second-order model. The adsorption force between the c-MWCNTMHs and Cu( Ⅱ) was of a chemical type and the saturated adsorbents can be regenerated at pH 2. 0. The magnetic Fe3O4 favored only the quick separation and had little contribution to adsorption. The low limit of Cu( Ⅱ) in water that was removable with the hybrids was 1. 29 μg /L.