Core/Shell Magnetite/Bismuth Oxide Nanocrystals with Tunable Size, Colloidal, and Magnetic Properties
Core/Shell Magnetite/Bismuth Oxide Nanocrystals with Tunable Size, Colloidal, and Magnetic Properties
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DOI：
10.1021/cm202949q
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发表时间：
2012-01-24
影响因子：
8.6
通讯作者：
Serna, Carlos J.
中科院分区：
文献类型：
--
作者：
Andres-Verges, Manuel;del Puerto Morales, Maria;Serna, Carlos J.
通过简单的水相路线合成了新型无机杂化纳米颗粒，将不同材料集成在铁和铋氧化物的核/壳结构中。该方法基于在温和氧化剂中存在铋(III)阳离子的情况下Fe(II)盐的沉淀，并产生高度均匀的结晶磁性纳米颗粒，尺寸在8至30 nm之间。 Bi与Fe原子比为1%至20%的铋充当表面活性剂，积聚在纳米颗粒表面，控制颗粒尺寸和胶体性质。通过 X 射线光电子能谱分析以及外壳中的铋富集揭示了核/壳结构的证据。这种坚固的材料具有非常长的化学稳定性和抗降解性、良好的磁性能以及由于铋离子的存在而具有的高密度，预计作为磁共振成像和计算机断层扫描的新型双造影剂在诊断中具有重要的应用。
New inorganic hybrid nanoparticles integrating different materials in a core/shell structure of iron and bismuth oxides have been synthesized by a simple aqueous route. The method is based on the precipitation of an Fe(II) salt in the presence of bismuth(III) cations in a mild oxidant and leads to highly uniform and crystalline magnetic nanoparticles with sizes in the range between 8 and 30 nm. Bismuth in proportions between 1 and 20% atomic ratio of Bi to Fe acts as surfactant being accumulated at the nanoparticle surface, controlling particle size and colloidal properties. Evidence of a core/shell structure is revealed by X-ray photoelectron spectroscopy analysis with bismuth enrichment in an outer shell. This robust material with very long chemical stability and resistance to degradation, good magnetic properties, and high density due to the presence of bismuth ions is expected to have important applications in diagnosis as a new double contrast agent for both magnetic resonance imaging and computed tomography.