1: CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, P. R. China

2: School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, P. R. China

3: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, P. R. China

摘要：Three-dimensional (3D) nanostructures composed of hierarchically assembled subunits have demonstrated enhanced affinity and sorption capability toward pollutants, compared with their bulk counterparts. In this study, hierarchically nanostructured maghemite (γ-Fe2O3) microspheres were prepared by a facile thermal decomposition of iron alkoxide in air. The synthesized products were characterized by a wide range of techniques including powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), thermogravimetry (TG) and differential scanning calorimetry (DSC), and Brunauer-Emmett-ler (BET) gas physical sorption isotherm. Moreover, the effects of pH, contact time, initial Sb concentration on the sorption of Sb by γ-Fe2O3 microspheres, and reusability of the sorbent were systematically investigated. The nanoscale γ-Fe2O3 microspheres exhibited excellent sorption ability to Sb(III) and Sb(V) with maximum sorption capacities of 128.2 and 98.7 mg·g−1 for Sb(III) and Sb(V) respectively. The Sb sorption on maghemite microspheres perfectly followed the pseudo-second-order kinetic model and Redlich-Peterson isotherm. Taking into account the simplicity of synthetic procedure, good reusability and possibility of magnetic separation of the sorbent with immobilized pollutants, the developed hierarchically nanostructured maghemite microspheres have good potential applications in water treatment.