Iron And Titanium Composite Oxide:Preparation And Adsorption Performance For Arsenic

In recent years,the arsenic contamination in water is increasingly serious,which seriously threatens human health and environmental security.Studies have shown that metal oxide composites is an economical and efficient material for arsenic rermoval.It has broad prospects in the remediation of arsenic pollution in water.However,there are some problems such as poor adsorption ability and difficult separation.Therefore,it has great research value and practical significance for arsenic wastewater purification to develop novel composite nanomaterials with high adsorption capacity and renewable property.In this paper,titanium oxide and magnetic iron oxide were selected as based materials to prepare binary metal oxide adsorbents,and unique ultrathin nanosheet and core-shell mesoporous nanostructures were constructed.The morphology,structure and chemical composition of the as-made adsorbents were characterized and analyzed,the performance of arsenic removal and regeneration were investigated.The main research contents and results are as follows:(1)Ultrathin magnetic Fe3O4@TiO2 nanosheet adsorbent was synthesized by sol-gel method and hydrothermal-assisted crystallization strategy,which has excellent performance for arsenic removal from waters.The ?-Fe2O3@amTiO2 sheets were obtained by sol-gel reaction between TBOT precursor and ultrathin ?-Fe2O3 nanosheets,which were prepared by hydrothermal method.Magnetic Fe3O4@TiO2 sheet-like adsorbent was obtained by hydrothermal crystallization and hydrogen reduction treatment.Morphological characterizatio n and structural analysis confirmed that the as-prepared magnetic Fe3O4@TiO2 adsorbent has ultrathin sheet-like nanostructure.TiO2 nanoparticles with small size were uniformly anchored on Fe3O4 nanosheets.Results of arsenic removal test showed that the maximum capacities of Fe3O4@TiO2 nanosheets adsorbent on As(?)and As(?)were 36.36 and 30.96 mg g-1,respectively.Moreover,the both residual concentrations were lower than 10 ?g L-1.(2)Monodispersed core-shell H-Fe3O4@mTiO2 mesoporous magnetic microspheres adsorbent was prepared by ethylene glycol-assisted coating approach and boiling water crystallization treatment,which has outstanding performance and excellent recycling ability for arsenic removal from water.The H-Fe3O4@Ti(EG)2 microspheres were obtained by hydrolysis and condensation reactions between modified titanium dioxide precursor and uniform hollow H-Fe3O4,which were synthesized by one-step hydrothermal method.Monodispersed core-shell H-Fe3O4@mTiO2 mesoporous magnetic hybrid nanomaterials were obtained by facile boiling water treatment.Morphological characterization and structural analysis demonstrated that as-synthesized H-Fe3O4@mTiO2 magnetic microspheres have uniform core-shell and mesoporous nanostructure,and the saturation magnetization of 31.91 emu g-1.Experimental results of arsenic removal showed that the maximum capacities of H-Fe3O4@mTiO2 magnetic microspheres adsorbent on As(?)and As(?)were 7.74 and 18.22 mg g-1,respectively.Moreover,the adsorption capacities remained 86%and 89%after five time regeneration cycles.