The Utilization Of Reduced Graphene Oxide-based Aerogels For Wastewater Treatment

As the environment has been seriously damaged by humanbeings,it is a threatening problem for human survival and ecological balance.Adsorption and photodegradation methods have been widely used because of their many advantages,such as easy operation,low cost and high removal efficiency,however,it has been heavily obstructed to apply by many shortcomings for the existed materials,for example,low efficiency and little recycling performance.Reduced graphene oxide（rGO）with excellent properties has great application value,while it is easy to reunite and stack between graphene slices,which hampered the extensive application of rGO.Based on graphene oxide（GO）,Montmorillonite（MMT）and molybdenum oxide（MoO₃）,the r GO-MMT composite aerogel and rGO-MoO₃ composite aerogel were prepared.By a series of characterization methods,the purification ability of pollutants in water was studied.First,GO was synthesized using a modified Hummers method,and the three-dimensional network of hydrogels was synthesized by the self-assembly process in the aqueous solution with GO,MMT,ascorbic acid（VC）and polyvinyl alcohol（PVA）and dried it by freeze-drying.the r GO-MMT composite aerogel was characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）and BET specific surface area.The results showed that the three-dimensional structure composite aerogels（rGO-MMT）have been successfully prepared with high porosity,low density and good mechanical properties.Second,the adsorption and antibacterial activity of rGO-MMT composite aerogel were studied.According to adsorption studies,the Langmuir isotherm model and the pseudo-second-order kinetics model could be applied to explain the adsorption mechanisms of MB and Cr（VI）.In addition,the rGO-MMT aerogel exhibited excellent recyclable property.Third,using GO,MoO₃,VC and PVA as raw materials,the rGO-based composite aerogels loaded with MoO₃ were synthesized by self-assembly process.The structures were characterized by XRD,FT-IR,SEM and TEM.The results showed that the three-dimensional network structure of rGO-based composite aerogels loaded with MoO₃ has been successfully synthesized.Fourth,the degradation properties of MB and MO in water were studied for rGO-MoO₃,and the degradation activity,recycling activity and degradation mechanism were studied.The results showed that the degradation rate of MB was good,and the degradation rate kept stable after 3 times cycling,while the degradation rate of MO was almost none.