Preparation And Adsorption Properties Of Wool Keratin/Graphene Oxide Composites

In order to improve the adsorption performance and adsorption rate of wool keratin,it was compounded with graphene oxide（GO）to prepare KE/GO composite film and KE/GO composite aerogel,respectively,and used for cationic dye MB and heavy metals Pb²⁺,Cu²⁺ of adsorption.The findings are as follows:（1）The KE solution was extracted by reducing C method.FT-IR analysis showed that KE was successfully prepared;wool dissolution rate was 61.3%,KE extraction rate was 53.9%,and molecular weight distribution of KE was between 17 and 54 KD.The thermal stability（TG）curve shows that the final weight loss rate of KE is 86.6% and the residual weight rate is 13.4%.The modified Hummers method was used to prepare GO solution.Through X-ray diffraction（XRD）,FT-IR,and TG analysis,graphite was successfully oxidized to GO.（2）Add 10%,20%,and 30% GO to the KE to prepare KE/GO composite films,respectively,FT-IR,XRD and TG were used to characterize the structure of KE/GO composite film.FT-IR analysis showed that the composite film has more polar oxygen-containing functional groups,which is conducive to the adsorption of heavy metal ions.XRD analysis showed that GO sheet was well dispersed in wool keratin matrix.It can be seen from the TG curve that the addition of graphene oxide has little effect on the thermal stability of the composite film.The results of Cu²⁺adsorption showed that: KE/GO（30%）composite film（90min）reached adsorption equilibrium faster than pure KE film（150min）.As the amount of GO added increased,the Cu²⁺ adsorption amount gradually increased.When the solution p H = 6-8,the temperature is 198 K,and the concentration is 100mg/L,the maximum adsorption capacity is 46mg/g.（3）KE and GO were solution-composited,self-assembled to form a hydrogel,and KE/GO（9: 1）composite aerogel was prepared after freeze-drying.SEM,FT-IR,XRD,TG and other methods were used to characterize the structure of the KE/GO composite aerogel: it can be seen that the KE/GO composite aerogel has a layered,ordered,sheet-folded porous structure.There are many active sites,large specific surface area,and good adsorption;The composite aerogel has a large number of polar functional groups,which is conducive to the adsorption of pollutantmolecules;graphene oxide sheets are uniformly dispersed in the wool keratin matrix;the addition of GO has little effect on the thermal stability of KE.The effects of time,p H value,temperature,and initial solution concentration on MB adsorption by KE/GO composite aerogel were discussed.The adsorption results showed that When the solution p H=6,the temperature was 298 K,and the composite aerogel reached the maximum equilibrium adsorption capacity for MB at about 120 min.Compared with pure KE,the adsorption rate and saturated adsorption capacity of KE/ GO composites are greatly improved.The removal rate of 100mg/L MB reached96%,which was 17% higher than that of pure KE,and the removal rates of 100mg/L Pb²⁺ and Cu²⁺ were 75% and 74%,respectively,which were 12% and 11% higher than those of pure KE.In addition,the adsorption of MB by KE/GO composites conforms to the Langmuir equation and pseudo-second-order kinetic model.