Study On The Green Synthesis And Adsorption Properties Of Fe,Cu Nanocomposites

With the rapid growth of population and the rapid development of economy,environmental problems are becoming increasingly prominent,and water pollution has become a major threat to life and health.It is urgent to find a green and simple method to deal with water pollution.Nanostructured adsorbent has become a research hotspot in recent years because of its clear shape,large specific surface area,controllable porosity and high treatment efficiency.However,mass production of nanomaterials to remove pollutants from water still faces many challenges,mainly due to the complexity of the synthetic methods involved and the use of hazardous reagents.The plant synthesis method of green preparation of nanomaterials can effectively solve these problems.The Fe,Cu nanocomposites（Fe-Cu-NCs）were synthesized using loquat leaf extract and used as a potential adsorbent for the removal of norfloxacin（NOR）,ciprofloxacin（CIP）and Light green（LG）from aqueous solution.Finally,the adsorption mechanism of Fe-Cu-NCs have been investigated.In this paper,Fe-Cu-NCs were synthesized using loquat leaf extract by a green and single-step method.The morphological structure and surface functional groups of the Fe-Cu-NCs were explored by Scanning electron microscope（SEM）,Transmission electron microscope（TEM）,X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,Specific surface area analysis（BET）,Fourier transform infrared spectrum（FTIR）and The point of zero charge(p H_PZC).The results showed that the Fe-Cu-NCs were spherical with an average particle size of 100～200 nm,and there were a large number of reactive functional groups such as carboxyl groups and hydroxyl groups on the surface of Fe-Cu-NCs.The effects of adsorption time,the p H of solution,temperature and initial solution concentration,adsorbent dose,salt concentration on the adsorption capacity of NOR,CIP and LG onto Fe-Cu-NCs were explored by a series of static adsorption experiments.The results showed that the optimal adsorption time of Fe-Cu-NCs for NOR,CIP and LG were 180、180 and 240 min,respectively.The adsorption amount was positively correlated with the adsorption time and concentration,the addition of salt ions inhibited the adsorption of Fe-Cu-NCs to NOR and CIP,but promoted the adsorption of LG.The adsorption kinetic models and adsorption isotherm models were used to fit the obtained experimental data.The results of kinetic study showed that the adsorption process of NOR and CIP fitted the Double-constant rate equation and Elovich model well,and the adsorption process of LG conformed to the Pseudo-second order model,and the Intra-particle diffusion was not the only rate-control step.The results of the adsorption isotherm showed that Redlich-Peterson and Koble-Corrigan models could better describe the adsorption process of NOR and CIP,and LG adsorption isotherm data were well fitted by Langmuir,Koble-Corrigan and Dubinin-Radushkevich models.The maximum adsorption capacity of Fe-Cu-NCs calculated by Langmuir model for NOR,CIP and LG were 1.182、1.103 and 0.114mmol/g at 293 K,respectively.In addition,the calculation results of thermodynamic parameters（ΔH、ΔG andΔS）showed that the adsorption process of the Fe-Cu-NCs to the three substances were spontaneous and endothermic.By analyzing the infrared spectrum of Fe-Cu-NCs before and after adsorption and the effect of p H on the adsorption amount,it is speculated that the adsorption mechanisms of NOR and CIP on Fe-Cu-NCs were electrostatic interaction,hydrogen bonding,hydrophobic interaction,n-πEDA interactions and surface complexation,and the adsorption mechanism of Fe-Cu-NCs for LG may be attributed to the electrostatic interaction,n-πEDA interactions and hydrogen bond.