Synthesis of mesoporous maghemite (γ-Fe2O3) nanostructures with enhanced arsenic removal efficiency

We successfully developed mesoporous gamma-Fe2O3 structures with a specific surface area of 35.7 m(2) g(-1) through atmospheric calcination of composite Fe3O4/phenol-formaldehyde resin structures, which were prepared by the addition of phenol during a hydrothermal process. For comparison, aggregated gamma-Fe2O3 nanoparticles with a specific surface area of 29.6 m(2) g(-1) were also prepared. The mesoporous gamma-Fe2O3 structures were used to adsorb arsenic ions, and the maximum uptake of arsenic ions was calculated to be 73.2 mg g(-1), which is higher than that of the aggregated gamma-Fe2O3 nanoparticles (32.3 mg g(-1)) because of the larger specific surface area, pore volume and pore sizes of the mesoporous gamma-Fe2O3 structures. In this study, we developed a feasible approach to wastewater treatment, including the removal of arsenic ions.