Preparation Of Graphene Oxide Composite Adsorbent And Study On Its Adsorption And Reduction Performance

In recent years,water pollution has seriously affected human health and the ecological environment.In this paper,the Hummers method is used to synthesize graphene oxide(GO)materials,the original oxidation polymerization method is used to synthesize polyaniline(PANI)and graphene oxide/polyaniline(GO/PANI)composite materials,and the impregnation method is used to synthesize polyethylene imine(PEI)modified GO/PANI composite material.The adsorbent was characterized by XRD,FT-IR,SEM and BET.The adsorption of organic dyes Congo Red and Cr(VI)in simulated wastewater was studied.The specific research contents are as follows:(1)Prepared GO,PANI,GO/PANI and PEI modified GO/PANI composite adsorbent successfully.Among them,the GO structure is a wrinkled lamellar layer structure,PANI is spherical and the agglomeration is serious,GO/PANI shows that polyaniline molecules are loaded on the GO sheet.Compared with GO/PANI,PEI/GO/PANI composite adsorbent maintains the crystal structure of GO/PANI,but the crystallinity and crystal morphology integrity are slightly reduced.(2)The optimal preparation conditions of PEI/GO/PANI modification were determined through static adsorption experiments,and adsorption experiments were carried out on Congo red and Cr(VI).The results show that the GO/PANI composite with 20%PEI molecules has the best adsorption effect on Congo red and Cr(VI)under the preparation temperature of 20?and the preparation time of 12h.At 20?,the pH is 5,the reaction When the time is 60min and 180min respectively,the adsorption capacity of PANI for Congo red and Cr(VI)is 70.54mg/g,64.14mg/g,and the adsorption capacity of GO/PANI is 267.83mg/g,78.71mg/g.The adsorption effect of the PEI modified GO/PANI composite adsorbent was increased to 355.32mg/g,87.84mg/g.The adsorption behavior of the three adsorbents conforms to the second-order kinetic model and Langmuir adsorption isotherm equation.(3)The results show that the PANI,GO/PANI,and PEI/GO/PANI adsorbed Congo red and Cr(?)composite particles internal diffusion model,Cr(?)produced in the adsorption experiment of Cr(?),indicating that the adsorbent has reducibility.After four cycles of regeneration experiments on Congo red and Cr(?)by three adsorbents,the adsorption capacity of PANI for Congo red and Cr(?)decreased from 170.54mg/g,64.14mg/g to 111.05mg/g,27.14mg/g respectively,GO/PANI adsorption capacity decreased from 267.83mg/g,78.71mg/g to 187.36mg/g,53.44mg/g,PEI/GO/PANI adsorption capacity decreased from 355.32mg/g,87.84mg/g to 269.65mg/g,69.27mg/g.It shows that the three kinds of adsorption have good desorption regeneration performance.