▎ 摘　　要

Hierarchical porous metal organic framework (MOF) composites are highly demanded because they can keep the high activity and good transport property simultaneously. A novel method of ionic liquidassisted growth of Cu-3(BTC)(2) on graphene oxide (GO) sheets was proposed and applied to improve both CO2 adsorption capacity and adsorption rate. Three ionic liquids (ILs) of triethylene tetramine acetate (TETA-Ac), triethylene tetramine tetrafluoroborate (TETA-BF4) and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) were used to investigate the effects of cations and anions of ILs on the structure of GO-IL/MOF composite. With amine or imidazole cations adsorbed at the surface of GO and the contrary anions closely attached, GO-ILs can provide a lot of active sites for the absorption of Cu2+ cations through the coordination. Just like a bridge, ILs assisted the initial growth of the first seed layer of Cu-3(BTC)(2) on the surface of GO. Among various GO-IL/MOP composites, GO-TAc/MOF-60 sample showed a superimposed structure, which lead to more accessible adsorption activity sites and shorten the transfer distance. Also, the GO sheets in GO-IL/MOF provide channels for faster transfer. It showed a high CO2 adsorption capability of 5.62 mmol/g at 25 degrees C and 100 kPa, and a high CO2 kinetic separation performance as well. More importantly, the composite presented a quite good cyclic adsorption/desorption stability. The relations between the specific structures of the composites and the CO2 adsorption behaviors were tentatively demonstrated to reveal a convenient way for designing and fabricating hierarchical MOF composites. (C) 2014 Elsevier Inc. All rights reserved.