Heru Setyawan, Fauziatul Fajaroh, W. Widiyastuti, Sugeng Winardi, I. Wuled Lenggoro, Nandang Mufti
Silica-coated magnetite nanoparticles have been synthesized successfully using a one-step electrochemical method. In this method, pure iron in a dilute aqueous sodium silicate solution that served as a silica precursor was electrooxidized. We show that the presence of silicate can significantly enhance the purity of the magnetite formed. Impurities in the form of FeOOH (found in the magnetite prepared in water) are not found. The magnetite nanoparticles produced by this method are nearly spherical with a mean size ranging from 6 to 10 nm, which is lower than the size of particles prepared in water, and this size range depends on the applied voltage and the sodium silicate concentration. The magnetite nanoparticles exhibit superparamagnetic properties with saturation magnetization ranging from 15 to 22 emu g-1, which is lower than the saturation magnetization of the Fe3O4 bulk materials (Ms = 92 emu g-1). This facile method appears to be promising as a synthetic route for producing silica-coated magnetite nanoparticles. © Springer Science+Business Media B.V. 2012.
Department of Chemical Engineering, Sepuluh Nopember Institute of Technology, Kampus ITS Sukolilo, Surabaya 60111, Indonesia; Department of Chemistry, Faculty of Mathematics and Science, Malang State University, Malang 65119, Jl. Semarang 5, Indonesia; Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Nakacho 2-24-16, Japan; Department of Physics, Faculty of Mathematics and Science, Malang State University, Malang 65119, Jl. Semarang 5, Indonesia
