Phosphate Adsorption Properties of Magnetite-Based Nanoparticles

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• 作者：T. J. Daou ; S. Begin-Colin ; J. M. Grenè ; che ; F. Thomas ; A. Derory ; P. Bernhardt ; P. Legaré ; G. Pourroy
• 刊名：Chemistry of Materials
• 出版年：2007
• 出版时间：September 4, 2007
• 年：2007
• 卷：19
• 期：18
• 页码：4494 - 4505
• 全文大小：621K
• 年卷期：v.19,no.18(September 4, 2007)
• ISSN：1520-5002

文摘

Magnetite nanoparticles of 40 nm in size have been phosphated in orthophosphoric acid. Largephosphatation rates, equivalent to goethite capacity, have been pointed out, and the possibility ofphosphatation-dephosphatation cycles has been proved. Phosphatation occurs rapidly, inhibits thedissolution of magnetite and does not modify the structure and the magnetization of magnetite. IRspectroscopy, X-ray photoelectron spectroscopy (XPS) analysis, and Mössbauer spectrometry have shownthat phosphatation occurs by interaction with both positively charged groups and hydroxyl sites at thesurface of magnetite and more precisely with Fe³⁺ in octahedral sites. The main surface species wouldbe a protonated binuclear species and the top layer would be in the (111) plane. The chemical stabilityof magnetite during cycling and its magnetic macroscopic moment allowing an easy recycling are promisingfor technological uses.