Freeze-Drying Graphene Aerogels and their Adsorption Ability towards Organic Reagents

Abstract

Graphene (GR) aerogels with three-dimensional interconnected network were prepared from freeze drying graphene oxide (GO) dispersions for adsorbing organic reagents. Microstructures of GR aerogels were observed by field-emission scanning electron microscopy, and the components were analyzed by X-ray photoelectron spectroscopy and X-ray diffraction. Their adsorption abilities and recycling performances for organic reagents were investigated in detail. The results showed that the adsorption capacity of GR aerogels was dependent on the concentration of GO dispersion. For example, the adsorption capacity of ethanol increased from 7.04 to 32 g/g when the GO concentration changed from 5 to 10 mg/ml. The GR aerogels also exhibited good adsorption performance for other organic reagents, reaching 44.78, 93.41 and 56.56 g/g for cyclohexane, acetone and methanol, respectively. Moreover, the 7GR had good cyclic adsorption capacity for cyclohexane, acetone and methanol, and the relative standard deviation was 3.7%, 4.3%, 3%, respectively.