Mechanochemical formation of superparamagnetic magnetite nanoparticles from ferrihydrite over a wide range of pH environments
Mechanochemical formation of superparamagnetic magnetite nanoparticles from ferrihydrite over a wide range of pH environments
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DOI：
10.1016/j.matchemphys.2013.04.011
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发表时间：
2013-07
影响因子：
4.6
通讯作者：
T. Iwasaki;N. Sato;Hideya Nakamura;S. Watano
中科院分区：
文献类型：
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作者：
T. Iwasaki;N. Sato;Hideya Nakamura;S. Watano
我们开发了一种利用机械力化学效应在环境友好的条件下(即在室温和不含有机溶剂的情况下)合成高晶态超顺磁性纳米颗粒的新方法。该方法以pH值为2.9~13.3的氢氧化铁(氢氧化铁)水悬浮液为原料(前驱体)，在不锈钢卧式球磨机中进行球磨。虽然在没有加热和没有任何还原剂的情况下进行了球磨，但仍然形成了直径为10-20纳米的磁铁矿纳米颗粒。这一结果表明，在球磨过程中，铁离子被还原为亚铁离子，导致氢氧化铁生成氢氧化亚铁。前驱体悬浮液的初始pH对所制备的磁性纳米颗粒的性能影响很小，表明这一过程不受初始pH变化的影响。用氧化还原反应描述了磁铁矿的形成，其中钢的腐蚀起着重要作用，初始pH值对磁铁矿的形成机理有很大影响。
We have developed a new aqueous-phase synthesis of highly crystalline superparamagnetic magnetite nanoparticles using mechanochemical effects under environmentally friendly conditions (i.e., at room temperature and without organic solvent). In this method, aqueous suspensions of ferric hydroxide (ferrihydrite) at pH values between 2.9 and 13.3 were used as the starting material (precursor) and milled in a stainless steel horizontal tumbling ball mill. Although the milling was performed without heating and in the absence of any reducing agent, magnetite nanoparticles with a diameter of 10–20 nm were formed. This result implies that ferric ions were reduced to ferrous ions during the milling, resulting in the formation of ferrous hydroxide from ferric hydroxide. The initial pH of the precursor suspensions had a minimal effect on properties of the magnetite nanoparticles thus produced, showing that this process is unaffected by variations in the initial pH. The formation of magnetite is described using oxidation–reduction reactions, in which the corrosion of steel plays an important role, and the initial pH greatly affects the reaction mechanism of magnetite formation.