Chemical Engineering Journal, Vol.327, 142-149, 2017
Fabrication of graphene millimeter-vortex ring with excellent absorption via solution dripping and in-situ reduction method
Graphene aerogels featuring ordered and controllable architectures represent promising candidates for use in water purification. In this context, a unique method for directing the self-assembly of graphene oxide (GO) nanoplatelets in a sodium hydrogen sulfite (NaHSO3) aqueous suspension is proposed, which leads to the formation of annular GO assemblies and ultimately turns into graphene millimeter-vortex ring (GMVR) aerogel after chemical reduction and freeze-drying process. In comparison to other spherical or cylindrical adsorbents, GMVR exhibits superior adsorption efficiency for the removal of contaminants, such as dyes and other organic solvents from wastewater. Particularly, the maximum adsorption capacity of GMVR for methylene blue was 1004 mg g (1), which is much higher than that of conventional graphene-based materials. The remarkable absorbability of GMVR materials is closely related to their increased surface area as well as the shortened diffusion pathway. Such approach of preparing GMVR composites provides potential route for the future development of excellent adsorbents. (C) 2017 Elsevier B.V. All rights reserved.