Study On The Preparation And Separation Performance Of Graphene Oxide Nano-silver Composite Film

Graphene oxide(GO)is the product of graphene oxidation reaction.In recent years,due to its simple production process and good chemical stability,it has been studied as a membrane material.GO films have negatively charged functional groups containing oxygen,allowing them to repel negatively charged organic dyes.This chapter characterizes and studies the preparation and properties of graphite oxide and graphene oxide/ silver nanoparticles(GO/AgNPs)composite membrane.The main work was divided into three parts:The modified Hummers method was used as the preparation method to produce graphite oxide.In order to remove the oxygen-containing functional groups in GO,sodium borohydride was used as a reducing agent to react with it.The resulting product was RGO(reduced graphene oxide).In order to characterize the surface morphology of the material,the material was tested by SEM and TEM,and the surface roughness of the material was characterized by AFM;UV-Vis and FTIR were used to characterize the chemical structure of the material and speculate the functional groups and reactions contained in the material changed in the chemical structure of the material afterwards;XRD was used to characterize the crystalline structure of the material,and the sheet spacing of the material was calculated by the Bragg equation.In the following research,the method of using sodium citrate to reduce silver nitrate under heating conditions was successfully used to prepare GO / AgNPs composite and GO / AgNPs compositemembrane,and tested with UV-Vis,FTIR,XRD,etc.It proved that the load was successfully loaded on the GO sheets.The morphology of GO / AgNPs composite was observed by TEM.The average diameter of AgNPs was about 8nm.Vacuum filtration were used to measure the water flux of GO and GO / AgNPs composite membranes and the RhB rejection rate.The experimental results showed that the layer spacing can be adjusted by loading AgNP,and the water flux can be greatly improved within the allowable range of the rejection loss.And the process of preparing GO / AgNPs composite membranes is green and pollution-free,and it is expected to continue to be developed and applied to large-scale production.In this study,GO-8,GO-20,GO-33 composites and composite membrane with AgNP average particle size of 8nm,20 nm,33nm were successfully prepared,and UV-Vis,XRD and other tests proved that they were successfully loaded onto GO sheet.The morphology of GO / AgNPs composites was observed by TEM.Theaverage diameters of the three composite AgNPs were around 8nm,20 nm and 33 nm.The vacuum filtration device was used to measure the water flux of GO,GO-8,GO-20 and GO-33 and the RhB rejection rate.The experimental results showed that the permeability and filtration performance of the membrane can be improved by adjusting the particle size of the loaded AgNP.The effect of the concentration of RhB solution on the rejection rate was further investigated and the results showed that the low concentration of RhB solution was beneficial to improve the filtration performance of the membrane.