Structure and Magnetic Properties of Nanocomposite Fe2O3/TiO2 Catalysts Fabricated by Heterogeneous Precipitation
The aim of our work is to study phase composition,
particle size and magnetic response of Fe2O3/TiO2 nanocomposites
with respect to the final annealing temperature. Those nanomaterials
are considered as smart catalysts, separable from a liquid/gaseous
phase by applied magnetic field. The starting product was obtained
by an ecologically acceptable route, based on heterogeneous
precipitation of the TiO2 on modified g-Fe2O3 nanocrystals dispersed
in water. The precursor was subsequently annealed on air at
temperatures ranging from 200 oC to 900 oC. The samples were
investigated by synchrotron X-ray powder diffraction (S-PXRD),
magnetic measurements and Mössbauer spectroscopy. As evidenced
by S-PXRD and Mössbauer spectroscopy, increasing the annealing
temperature causes evolution of the phase composition from
anatase/maghemite to rutile/hematite, finally above 700 oC the
pseudobrookite (Fe2TiO5) also forms. The apparent particle size of
the various Fe2O3/TiO2 phases has been determined from the highquality
S-PXRD data by using two different approaches: the Rietveld
refinement and the Debye method. Magnetic response of the samples
is discussed in considering the phase composition and the particle
size.
[1] B. Pal, M. Sharon, G. Nogami, "Removal of natural organic matter from
water using a nano-structured photocatalyst coupled with filtration
membrane", Mater. Chem. Phys., vol. 59, pp. 254-261, 1999.
[2] J.A. Navio, G. Colon, M.I. Litter, G.N. Bianco, "Synthesis,
characterization and photocatalytic properties of iron-doped titania
semiconductors prepared from TiO2 and iron(III) acetylacetonate", J.
Mol. Catal. A. Chem., vol. 106, pp. 267, 1996.
[3] D. Sun, T.T. Meng, T.H. Loong, T.J. Hwa, "Removal of natural organic
matter from water using a nano-structured photocatalyst coupled with
filtration membrane", Water Sci. Technol., vol. 19, pp. 315601, 2008.
[4] S.K. Mohapatra, S. Banerjee, M. Misra,, "Synthesis of Fe2O3/TiO2
nanorod-nanotube arrays by filling TiO2 nanotubes with Fe",
Nanotechnology, vol. 49, pp. 103-110, 2004.
[5] J. Morales, L. Sanchez, F. Martin, F. Berry, X. Ren, "Synthesis and
Characterization of Nanometric Iron and Iron-Titanium Oxides by
Mechanical Milling: Electrochemical Properties as Anodic Materials in
Lithium Cells", J. Electrochem. Soc., vol. 152, pp. A1748-A1754, 2005.
[6] V. Tyrpekl, J. P. Vejpravova, A. Roca, N. Murafa, L. Szatmary and D.
Niznansky, "Magnetically separable photocatalytic composite g-
Fe2O3@TiO2 synthesized by heterogeneous precipitation", Appl. Surf.
Sci., vol. 257, pp. 4844-4848, 2011.
[7] B. E. Warren, X-ray Diffraction, Dover Publications, New York, 1990.
[8] V. Vales, J. P. Vejpravova, V. Holy, V. Tyrpekl, P. Brazda and S.
Doyle, "Study of the phase composition of Fe2O3 and Fe2O3/TiO2
nanoparticles using X-ray diffraction and Debye formula", Phys. Status
Solidi C, vol. 7, pp. 1399-1404, 2010.
[9] J. Rodriguez-Carvajal, FullProf User-s Guide Manual, CEA-CRNS,
France, 2000.
[10] S.N. Klausem, K. Lefmann, P.-A. Lingard, L. T. Kuhn, C.R.H. Bahl, C.
Frandsen, S. Morup, B. Roessli, N. Cavadini, C. Niedermayer,
"Magnetic anisotropy and quantized spin waves in hematite
nanoparticles", Phys. Rev. B, vol. 70, pp. 214411, 2004.
[11] S.N. Klausem, K. Lefmann, P.-A. Lingard, L. T. Kuhn, C.R.H. Bahl, C.
Frandsen, S. Morup, B. Roessli, N. Cavadini, C. Niedermayer,
"Magnetic anisotropy and quantized spin waves in hematite
nanoparticles", Phys. Rev. B, vol. 70, pp. 214411, 2004.
[1] B. Pal, M. Sharon, G. Nogami, "Removal of natural organic matter from
water using a nano-structured photocatalyst coupled with filtration
membrane", Mater. Chem. Phys., vol. 59, pp. 254-261, 1999.
[2] J.A. Navio, G. Colon, M.I. Litter, G.N. Bianco, "Synthesis,
characterization and photocatalytic properties of iron-doped titania
semiconductors prepared from TiO2 and iron(III) acetylacetonate", J.
Mol. Catal. A. Chem., vol. 106, pp. 267, 1996.
[3] D. Sun, T.T. Meng, T.H. Loong, T.J. Hwa, "Removal of natural organic
matter from water using a nano-structured photocatalyst coupled with
filtration membrane", Water Sci. Technol., vol. 19, pp. 315601, 2008.
[4] S.K. Mohapatra, S. Banerjee, M. Misra,, "Synthesis of Fe2O3/TiO2
nanorod-nanotube arrays by filling TiO2 nanotubes with Fe",
Nanotechnology, vol. 49, pp. 103-110, 2004.
[5] J. Morales, L. Sanchez, F. Martin, F. Berry, X. Ren, "Synthesis and
Characterization of Nanometric Iron and Iron-Titanium Oxides by
Mechanical Milling: Electrochemical Properties as Anodic Materials in
Lithium Cells", J. Electrochem. Soc., vol. 152, pp. A1748-A1754, 2005.
[6] V. Tyrpekl, J. P. Vejpravova, A. Roca, N. Murafa, L. Szatmary and D.
Niznansky, "Magnetically separable photocatalytic composite g-
Fe2O3@TiO2 synthesized by heterogeneous precipitation", Appl. Surf.
Sci., vol. 257, pp. 4844-4848, 2011.
[7] B. E. Warren, X-ray Diffraction, Dover Publications, New York, 1990.
[8] V. Vales, J. P. Vejpravova, V. Holy, V. Tyrpekl, P. Brazda and S.
Doyle, "Study of the phase composition of Fe2O3 and Fe2O3/TiO2
nanoparticles using X-ray diffraction and Debye formula", Phys. Status
Solidi C, vol. 7, pp. 1399-1404, 2010.
[9] J. Rodriguez-Carvajal, FullProf User-s Guide Manual, CEA-CRNS,
France, 2000.
[10] S.N. Klausem, K. Lefmann, P.-A. Lingard, L. T. Kuhn, C.R.H. Bahl, C.
Frandsen, S. Morup, B. Roessli, N. Cavadini, C. Niedermayer,
"Magnetic anisotropy and quantized spin waves in hematite
nanoparticles", Phys. Rev. B, vol. 70, pp. 214411, 2004.
[11] S.N. Klausem, K. Lefmann, P.-A. Lingard, L. T. Kuhn, C.R.H. Bahl, C.
Frandsen, S. Morup, B. Roessli, N. Cavadini, C. Niedermayer,
"Magnetic anisotropy and quantized spin waves in hematite
nanoparticles", Phys. Rev. B, vol. 70, pp. 214411, 2004.
@article{"International Journal of Chemical, Materials and Biomolecular Sciences:49785", author = "Jana P. Vejpravova and Daniel Niznansky and Vaclav Vales and Barbara Bittova and Vaclav Tyrpekl and Stanislav
Danis and Vaclav Holy and Stephen Doyle", title = "Structure and Magnetic Properties of Nanocomposite Fe2O3/TiO2 Catalysts Fabricated by Heterogeneous Precipitation", abstract = "The aim of our work is to study phase composition,
particle size and magnetic response of Fe2O3/TiO2 nanocomposites
with respect to the final annealing temperature. Those nanomaterials
are considered as smart catalysts, separable from a liquid/gaseous
phase by applied magnetic field. The starting product was obtained
by an ecologically acceptable route, based on heterogeneous
precipitation of the TiO2 on modified g-Fe2O3 nanocrystals dispersed
in water. The precursor was subsequently annealed on air at
temperatures ranging from 200 oC to 900 oC. The samples were
investigated by synchrotron X-ray powder diffraction (S-PXRD),
magnetic measurements and Mössbauer spectroscopy. As evidenced
by S-PXRD and Mössbauer spectroscopy, increasing the annealing
temperature causes evolution of the phase composition from
anatase/maghemite to rutile/hematite, finally above 700 oC the
pseudobrookite (Fe2TiO5) also forms. The apparent particle size of
the various Fe2O3/TiO2 phases has been determined from the highquality
S-PXRD data by using two different approaches: the Rietveld
refinement and the Debye method. Magnetic response of the samples
is discussed in considering the phase composition and the particle
size.", keywords = "X-ray diffraction, profile analysis, Mössbauer
spectroscopy, magnetic properties, TiO2, Fe2O3, Fe2TiO5", volume = "6", number = "1", pages = "1-4", }