State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China.
ACS Appl Mater Interfaces. 2012 Aug;4(8):3987-93. doi: 10.1021/am300814q. Epub 2012 Jul 24.
To obtain adsorbents with high As(V) removal capacity and quick magnetic separation simultaneously, we have fabricated maghemite (γ-Fe(2)O(3)) and magnetite (Fe(3)O(4)) chestnutlike hierarchical nanostructures (CHNs) with strong ferromagnetic property by annealing the Fe(2)O(3) chestnutlike amorphous core/γ-phase shell hierarchical nanoarchitectures (CAHNs) at different temperatures in a nitrogen atmosphere. Compared to the Fe(2)O(3) CAHNs, the saturated magnetization of the as-obtained γ-Fe(2)O(3) CHNs is enhanced over 10 times, while the As(V) removal capacity is maintained 74% and reaches 101.4 mg·g(-1). Both of the as-obtained γ-Fe(2)O(3) and Fe(3)O(4) CHNs can be separated simply and rapidly from treated water by magnetic separation after As(V) adsorption treatment. The As(V) adsorption process of the as-obtained γ-Fe(2)O(3) CHNs obeys well the Freundlich isotherm model rather than the Langmuir one, suggesting that a multilayered adsorption occurs on the surface of the γ-Fe(2)O(3) CHNs. Taking advantages of the high adsorption capacity, fast adsorption rate and quick magnetic separation from treated water, the γ-Fe(2)O(3) CHNs developed in the present study is expected to be an efficient magnetic adsorbent for As(V) removal from aqueous solutions.
为了同时获得高砷（V）去除能力和快速磁分离的吸附剂，我们通过在氮气气氛中在不同温度下退火 Fe(2)O(3) 板栗状无定形核/γ 相壳层分级纳米结构 (CAHNs)，制备了具有强铁磁性的磁赤铁矿 (γ-Fe(2)O(3)) 和磁铁矿 (Fe(3)O(4)) 板栗状分级纳米结构 (CHNs)。与 Fe(2)O(3) CAHNs 相比，所得 γ-Fe(2)O(3) CHNs 的饱和磁化强度提高了 10 倍以上，而砷（V）去除能力保持在 74%，达到 101.4 mg·g(-1)。吸附砷（V）处理后，所得的γ-Fe(2)O(3) 和 Fe(3)O(4) CHNs 均可通过磁分离从处理水中简单快速地分离。所得γ-Fe(2)O(3) CHNs 的砷（V）吸附过程较好地遵循了 Freundlich 等温模型，而不是 Langmuir 模型，表明在γ-Fe(2)O(3) CHNs 的表面发生了多层吸附。由于具有高吸附容量、快速吸附速率和从处理水中快速分离的优势，本研究中开发的γ-Fe(2)O(3) CHNs 有望成为从水溶液中去除砷（V）的高效磁性吸附剂。
