Portal de Periódicos da CAPES

Phosphate Adsorption Properties of Magnetite-Based Nanoparticles

2007; American Chemical Society; Volume: 19; Issue: 18 Linguagem: Inglês

10.1021/cm071046v

1520-5002

T. Jean Daou, Sylvie Bégin‐Colin, Jean‐Marc Grenèche, Faium Thomas, A. Derory, Peter Bernhardt, P. Légaré, G. Pourroy,

Nanomaterials for catalytic reactions

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