Preparation Of Graphene Oxide/MnO₂ Nanorod Composite And Absorbbing Property

Recently water contamination was reported due to excessive antibiotic levels of river.It is necessary that the pretreatment of antibiotic from wastewater and advanced treatment for drinking water.Graphene has been widely studied in various fields.But it is usually agglegeted,and thus we make some efforts to improve its disadvantage.The objective of this study was to obtain the uniform MnO_2/graphene oxide nanorod composite material with high specific surface area for ciprofloxacin removel.Therein,the graphene oxide prepared by the modified Hummers method was well exfoliated into single layer and highly oxidized.The MnO₂ nanorods,which were confirmed by SEM,were produced by the hydrothermal method and oxidation-reduction process,respectively.According to SEM images,we found that the rod-shaped manganese dioxide having a uniform structure by Bisolvent coprecipitation than by hydrothermal.what's more,manganeae by Bisolvent coprecipitation longer and finer than another one.Therefore,the bisolvent?isopropanol and water?coprecipitation method was choosen to prepare rod-like manganese dioxide/graphene oxide composites.The preparation conditions are as follows:the mass ratio of manganese dioxide to graphene oxide is 1:1,the volume ratio of isopropyl alcohol to water is 10:1,and the addition of water requires rapid dropwise addition.The prepared composites were characterized by SEM,XRD,Raman and other structures.The results showed that manganese dioxide was supported on the surface of graphene and showed a uniform rodstructure.The crystal form of manganese dioxide was?-MnO₂.The adsorptive property of ciprofloxacin onto MnO_2/graphene oxide nanorod composite was additionally studied.It could be observed that the best adsorption performance of M1G1(200 mg·L^-1)could remove 90%of ciprofloxacin(50 mg·L^-1)within 4 h,and the equilibrium time was 24 h with the removal rate of 97.8%.Kinetics and thermodynamics study indicated the pseudo-second-order and Langmuir isotherm was better fitted for this adsorption process.Moreover,the M1G1 possessed the good stability which could keep more than 60%removal efficiency after three cycle uses.On one hand,the composite of rod-like manganese dioxide and graphene can enhance the stability of graphene oxide,increase the specific surface area and reduce the cost of graphene oxide as an adsorbent material.Therefore,it is of practical significance to make a study for the preparation of this material.