Study On The Preparation, Characterization And Adsorption Properties Of Graphene Oxide/tofu Composite Materials

Nowadays,with the further development of human civilization,people are increasingly pursuing the colorful world.The most basic manifestation is the large-scale use of various dyes by mankind.These dyes in enriching the color of people's lives,but also brought a lot of environmental pollution problems.As we all know,dyes are mostly organic compounds,which are more harmful.Wastewater containing dyes is randomly discharged into the environment,which often has a serious impact on the natural environment.Therefore,the dye-containing wastewater before its disposal to the environment,its purification is very necessar y.At present,common treatment methods include adsorption,membrane separation,chemical solidification,biological treatment,photocatalytic degradation,etc.The adsorption method is widely used in sewage treatment due to its high efficiency,low cost and simple operation.Tofu,a common food in life,is rich in large amounts of protein,meaning it is rich in oxygen-containing functional groups.Graphene is a kind of two-dimensional carbon nano-material with hexagonal honeycomb lattice composed of sp2 hybrid orbitals.It has excellent optical,electrical and mechanical properties.As a graphene oxide,graphene oxide flakes are products of chemical oxidation and stripping of graphite powder.Graphene oxide is also a new type of carbon material with excellent properties,and has a high specific surface area and abundant surface functional groups.In this paper,the adsorption of these two substances on the dye has been studied.In this paper,the adsorption of congo red dye by tofu prepared by freeze-drying method and the adsorption of methylene blue dye by graphene oxide / tofu composite prepared by the methods of heating blending and freeze-drying were studied respectively.The influence of different factors on the adsorption effect was studied through sys tematic experiments,and it was proved that the prepared materials have higher adsorption capacity to adsorb dyes.Adsorption of congo red dye by freeze-drying tofu was carried out through a series of experiments to study the effect of drying method,p H va lue of solution,amount of adsorbent,contact time and temperature on the adsorption of congo red on tofu.The experimental data for the isotherm are described by the Langmuir and Freundlich isotherms.K inetic data were analyzed using quasi-first-order,quasi-second order and intraparticle diffusion equations.The equilibrium thermodynamic parameters show that Congo red adsorbs on tofu is an endothermic and spontaneous process.The experimental scheme for the adsorption of methylene blue dye on graphene oxide / tofu composites is basically the same as the above scheme.The experimental results show that graphene oxide / tofu composite can effectively adsorb methylene blue in solution,and the equilibrium adsorption data accord with Langmuir model.Adsorption kinetics studies show that quasi-second-order kinetic model can more accurately describe the adsorption data of graphene oxide / tofu composite to methylene blue;thermodynamic parameters indicate that the adsorption is an endothermic and spontaneous process.