Fabrication of magnetic porous Fe-Mn binary oxide nanowires with superior capability for removal of As(III) from water.

Magnetic porous Fe-Mn binary oxide nanowires were successfully fabricated to efficient removal of As(III) from water. The adsorption capacity of the porous nanowires for As(III) obviously increased with increasing of manganese oxide in the composite, accompanying decrease of the saturation magnetization of the adsorbents. Magnetic porous Fe-Mn binary oxide nanowires with an initial Fe:Mn molar ratio of 1:3 exhibited the highest absorption capacity for As(III) and enable magnetic separation from water. The maximal adsorption capacity value is 171mgg(-1) at pH 7.0. In the initial pH range from 3 to 9, 200µgL(-1) of As(III) could be easily decreased to below 10µgL(-1) by the magnetic porous Fe-Mn binary oxide nanowires (0.05gL(-1)) within 75min, and the corresponding residual As was completely oxidized to less toxic As(V). The coexisting chloride, nitrate and sulfate had no significant effect on arsenic removal, whereas, phosphate and humic acid reduced the removal of As(III) by competing with arsenic species for adsorption sites. The resulting magnetic porous Fe-Mn binary oxide nanowires could be a promising adsorbent for As(III) removal from water.

One step solvothermal synthesis of functional hybrid γ-Fe2O3/carbon hollow spheres with superior capacities for heavy metal removal.

One-step hydrothermal method was developed to prepare hybrid γ-Fe2O3/carbon hollow spheres with a predominant orientation (111) plane of γ-Fe2O3 and rich oxygen-containing functional groups on carbon. The resulting functional hybrid exhibited extremely high adsorption capacities for toxic Pb(II) and Cr(VI) ions in solutions with easy magnetic separation. The ease of synthesis and low cost, coupled with the efficient and rapid removal of toxic heavy metal ions, make hybrid γ-Fe2O3/carbon hollow spheres an attractive adsorbent for the purification of waste and contaminated water.