The Preparation Of Graphene Nanocomposite And Application In Environmental Analysis

Graphene, because of its large specific surface area and rich oxygen containing functional group on the surface, possess a strong adsorption capacity and huge potential application in the treatment of dye water. However, the long adsorption equilibrium time and low adsorption capacity of graphene caused by reunion restrict its practical application. Graphene hybridized with other materials can not only solve the above two problems but also enhance their performance. Magnetic graphene/chitosan composites are environmental friendly materials which showed an enhanced adsorption capacities. We prepared G-Fe3O4/CA composite hydrogel by encapsulating magnetic graphene in calcium alginate. The as prepared G-Fe3O4/CA composite hydrogel showed an increased adsorption ability, at the same time, they are very easy to be separated from water solution. G-SnS2-Mg(OH)2 nanocomposite have larger specific surface area and also showed excellent adsorption performance.(1) ZnFe2O4@CS/GO nanocomposites removal of fuchsine from aqueous solutionIn this experiment, a new type of graphene nanocomposites was prepared by using a magnetic chitosan encapsulated in graphene oxide layer. The obtained ZnFe:O4@CS/GO composites were applied in adsorbing fuchsine from water solution. ZnFe2O4@CS/GO adsorption showed enhanced adsorption capacity as compared to the origin GO. Adsorption of fuchsine onto ZnFe2O4@CS/GO are greatly influenced by pH value, demonstrating the adsorption is via an ion exchange process. The adsorption follows the Lagergren second-order kinetics, and equilibrium data conforming with Langmuir isotherm. As a result, the novel ZnFe2O4@CS/GO adsorbent has great potential in water treatment because of its efficiency, environmental friendly, and the characteristics of magnetic separation.(2) G-Fe3O4/CA nanocomposites removal of methylene blue from aqueous solutionBy encapsulating Magnetic graphene (graphene with Fe3O4 composites) in calcium alginate, we prepared G-Fe3O4/CA composite hydrogel as an adsorbent to remove MB from aqueous solution. G-Fe3O4/CA have a great adsorption capacity for MB. The adsorption process is independent on the solution pH, following Lagergren second-order kinetics, and equilibrium data conforming with Langmuir isotherm. The results demonstrated the adsorption is a spontaneous process. Therefore, this new type of G-Fe3O4/CA can be applied as environmental and economical adsorbent is very promising.(3) G-SnS2-Mg(OH)2 nanocomposite for the adsorption of methylene blueGraphene-SnS2-Mg(OH)2 nanocomposites are prepared and applied for the adsorption of methylene blue from water solution. The material’s adsorbent dosage, dye concentration, equilibrium time and dynamics for the adsorption of methylene blue were investigated. The adsorbent materials have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectrometer, scanning electron microscope and electron transmission microscope. Equilibrium adsorption data suitable for Langmuir isotherm and the maximum adsorption capacity of G-SnS2-Mg(OH)2 is 275.51 mg/g. Equilibrium adsorption data was fit for in pseudo-second-order kinetics equation showed G-SnS2-Mg(OH)2 nanocomposite has a higher rate of dynamic adsorption.