| Three-dimensional graphene is a three-dimensional structure material composed of two-dimensional graphene,which has aroused widespread concerns of researchers in various fields due to its numerous superior physical and chemical properties.Among them,the large surface area and excellent stability of 3D graphene make it an excellent adsorbent for environmental applications.Chitosan(CS),the deacetylation derivative of chitin,which possesses good biocompatibility,have been widely used as biosorbents in the removal of several types of contaminants.?-cyclodextrin(?-CD)is a cyclic oligosaccharide that consists of seven ?-D-glucose units connected through ?-(1,4)linkages,which has an interesting structure with a hydrophobic inner cavity and a hydrophilic exterior.This characteristic enables ?-CD to form inclusion complexes with contaminants.However,the poor mechanical and easy dispersibility of CS and ?-CD limit the wide range of their applications in adsorption.Therefore,on the basis of combining the respective advantages of three-dimensional graphene,chitosan and ?-cyclodextrin,a novel three-dimensional graphene/chitosan/?-cyclodextrin functional materials(3D-GO/CS/?-CD)with was prepared by one-step chemical reduction method in this study,and the adsorbent was characterized by many characterization methods,such as scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy.Besides,3D-GO/CS/?-CD was also used as an adsorbent to remove methylene blue(MB)and ciprofloxacin(CIP)from aqueous,and the adsorption kinetics,isotherm,thermodynamics,influencing factors(such as pH and ionic strength),regeneration performance and adsorption mechanism were also studied.The results indicate that 3D-GO/CS/?-CD with abundant three-dimensional porous structure was successfully synthesized,and the surface of 3D-GO/CS/?-CD has more functional groups with the addition of CS and ?-CD.The adsorption performance of 3D-GO/CS/?-CD onto MB and CIP are both improved.The adsorption kinetics of 3D-GO/CS/?-CD onto MB and CIP conforms to the pseudo-second-order kinetic model,the adsorption rate is controlled by both outer diffusion and inner diffusion.The adsorption isotherm of 3D-GO/CS/?-CD to MB fits to the Frendlich model,while the adsorption isotherm of 3D-GO/CS/?-CD to CIP fits to the Langmuir model,and the maximum adsorption capacitity for MB and CIP is 1134 mg/g and 189 mg/g,respectively.The adsorption thermodynamics shows that the adsorption process of MB and CIP onto 3D-GO/CS/?-CD are both spontaneous endothermic reaction,and more conducive at high temperature.Besides,the initial pH value and ionic strength of solution have influence on the adsorption of MB and CIP onto 3D-GO/CS/?-CD.Finally,the regeneration of 3D-GO/CS/?-CD was also discussed.The results showed that 3D-GO/CS/?-CD has good recycling ability,so it has great potential in the application of dye wastewater and antibiotic wastewater. |
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