Preparation Of Fe₃O₄@TiO₂ Magnetic Nanoparticles And Study On The Adsorption Of Heavy Metals

With the development of society,the pollution of heavy metals caused by industrial pollution,traffic pollution and domestic waste has caused serious harm to the environment and organisms.Heavy metals are difficult to be biodegraded by the environment,and can be enriched by the biological amplification of the food chain in higher organisms.Nano titanium dioxide(TiO2)has the characteristics of chemical stability,nontoxicity,and excellent performance in the removal of various inorganic and organic pollutants in water and air.However,it is difficult to separate from the reaction system after the reaction.The magnetic nanoparticles have chemically active surface and large surface area,which can be used to extract a certain range of ions from aqueous solution.In addition,their superparamagnetic properties provide a convenient means of collecting material from the solution after the target ion is adsorbed,but it is easy to produce reactive surface area loss due to particle aggregation.Herein,the Fe3O4@TiO2 magnetic nanocomposite as an efficient adsorbent was synthesized by sol-gel and hydrothermal process for the removal of lead from aqueous solution.The nanocomposite was characterized by Brunauer-Emmett-Teller(BET),Vibrating sample magnetometer(VSM),scanning electron microscopy(SEM)andTransmission Electron Microscopy(TEM),Fourier-transform infrared(FT-IR),X-ray photoelectron spectroscopy(XPS).The result exhibited that the as-prepared nanocomposite had high specific surface areas(124.178 m2·g-1),superparamagnetic property,thorn ball morphology.The adsorption property of Fe3O4@TiO2 was investigated in detail such as the effects of pH,contact time,initial concentration and temperature by a batch-adsorption technique.The maximum adsorption capacities of Pb(?)ions was 588 mg·g-1 at equilibrium time of 20 min and 313 K.The adsorption equilibrium data were well fitted to Langmuir and Freundlich isotherm models,and could be described by pseudo-second order model.The thermodynamics of Pb(?)adsorption onto the Fe3O4@TiO2 nanoadsorbents indicated that the adsorption was spontaneous,endothermic and physical in nature.Overall,due to its fast adsorption rate,high adsorption capacity,easy magnetic separation and features of regeneration,it shows good potential for water treatment.