Preparation of graphene oxide aerogel and its adsorption for Cu2+ ions

Graphene oxide (GO) aerogels were prepared by a unidirectional freeze-drying method (UFDM), their structure was observed and their adsorption performance for Cu2+ in aqueous solution was evaluated. The results show that GO aerogels have unidirectional porous structure and good adsorption ability for Cu2+. The adsorption system is depended on the Cu2+ concentration and follows a pseudo second-order kinetic model. The adsorption equilibrium is reached soon. The adsorption isotherms are simulated well by the Langmuir model. The adsorption of Cu2+ on GO aerogels is strongly dependent on pH, indicating an ion exchange mechanism. The obtained results demonstrated that the GO aerogels can be used as an effective adsorbent for Cu2+ removal from water. (C) 2012 Elsevier Ltd. All rights reserved.