Synthesis and characterization of CuFe2O4/CeO2 nanocomposites

doi:10.1016/j.matchemphys.2008.05.094

Materials Chemistry and Physics

Volume 112, Issue 2, 1 December 2008, Pages 373-380

https://doi.org/10.1016/j.matchemphys.2008.05.094 Get rights and content

Abstract

CuFe₂O₄/xCeO₂ (x = 0, 1, 5, 10 and 20 wt%) nanocomposites have been prepared by urea–nitrate combustion method. The particle size of the as-prepared CuFe₂O₄/5 wt% CeO₂ nanocomposite is 5–10 nm which has been revealed from TEM and HRTEM images. The as-synthesized materials have been sintered at four different temperatures (600, 800, 1000 and 1100 °C) for 5 h. The XRD analysis of the samples reveals that the prepared materials possess tetragonal structure and have the composite behaviour. The 1100 °C sintered samples have further been characterized by FT-IR, UV–vis, SEM, ac electrical conductivity, dielectric constant, loss tangent, and Mössbauer spectra. The SEM images clearly show that CeO₂ grows on the surface of the CuFe₂O₄. The electrical properties enumerate the ferrimagnetic behaviour of the synthesized materials. The Mössbauer spectra confirm both the inverse spinel structure of the prepared materials and the Fe³⁺ state of iron ions.

Introduction

Synthesis and characterization of nanocomposites have gained prominent interest in recent years due to their tailor-made properties. The term nanocomposite encompasses a variety of distinctly different materials mixed at the nanometric scale with specific applications. Some of the reported types of nanocomposites are magnetic–metal (Fe₃O₄–Au) [1], magnetic–metallic oxide (Zn, Ni Ferrite–NiO) [2], magnetic–polymer (CoFe₂O₄–Polypyrolle) [3], magnetic–semiconductors (Fe₃O₄–PbS) [4], magnetic–alloy ((Ni_0.5Zn_0.5) Fe₂O₄–FeNi₃) [5], magnetic–zeolite [6], etc. The present study deals with the spinel structure (CuFe₂O₄) made as composite with the layered fluorite-type structure (CeO₂) and its characterization. In particular, CuFe₂O₄ has unique characteristics when compared with other metallic ferrites because of its Jahn–Teller (Cu²⁺) ions. The ideal CuFe₂O₄ is known to be an inverse spinel, where Cu²⁺ ions occupy octahedral [B] sites and Fe³⁺ ions occupy both tetrahedral (A) and octahedral sites. However, it is widely known that the cation distribution in CuFe₂O₄ is a complex function of processing parameters and depends on the preparation method of the material.

Very recently, spinel type ferrites such as CoFe₂O₄ [7], [8], NiFe₂O₄ [9], [10], ZnFe₂O₄ [11], and CaFe₂O₄ [12] have gained a prominent interest in the field of energy storage devices especially negative electrodes in Li-ion batteries. In this regard, we have recently reported on CuFe₂O₄/SnO₂ nanocomposite [13] as a potential alternative anode for Li-ion batteries. Subsequently, here we have prepared CuFe₂O₄/CeO₂ nanocomposite and characterized the structural, electrical and magnetic properties of the materials. The EXAFS and XANES studies of CuFe₂O₄/xCeO₂ (x = 0, 5, 20 wt%) nanocomposites have been reported elsewhere [14]. CeO₂ is supposed to be one of the most favorable candidate for the anode material [15], [16] in Li-ion batteries when compared with other metal oxides of SnO₂ [17], TiO₂ [18], Fe₂O₃ [19] and NiO [20] due to its unique properties such as large oxygen storage capacity, high thermal stability, facile electrical conductivity, diffusivity and the variable valency of Ce³⁺ and Ce⁴⁺ [16]. Similarly, the surface modification [21] is an important phenomenon in Li-ion batteries leading to an enhancement of the electrochemical activity of the electrodes. Among the surface-modified functional oxide materials [22], [23], CeO₂ has gained enormous interest due to an enhancement of the electrochemical stability of the positive electrodes including LiMn₂O₄ [24], LiCoO₂ [25] and LiNi_0.8Co_0.2O₂ [26].

Hence, considering the importance of the surface modified nanocomposites, a detailed preliminary study has been carried out on nanocrystalline CuFe₂O₄ with CeO₂ at four different concentrations of 1, 5, 10, 20 wt% prepared by simple combustion method. The structural (XRD, FT-IR, UV–vis spectra), morphological (SEM, TEM, HRTEM, SAED), electrical (ac electrical conductivity, dielectric constant, loss tangent) and magnetic (Mössbauer spectra) properties of the material have also been investigated and reported herein.

Section snippets

Experimental

The CuFe₂O₄/x wt% CeO₂ (x = 0, 1, 5, 10, 20) nanocomposites were prepared using urea–nitrate combustion method [27]. The stoichiometric quantities of starting materials, viz., Cu(NO₃)₂·6H₂O, Fe(NO₃)₃·9H₂O, Ce(NO₃)₃ and CO(NH₂)₂ were dissolved in 100 ml distilled water. The actual quantities of the reactants for the preparation of each nanocomposite (for 100 g) and the yields are given in Table 1. The mixed nitrate–urea solution was heated at 110 °C, with continuous stirring. After the evaporation of

Structural studies

The XRD patterns of as-prepared CuFe₂O₄/x wt% CeO₂ nanocomposites and thermally treated at different temperatures (600, 800, 1000 and 1100 °C) are shown in Fig. 1. The as-prepared (Fig. 1a) sample contains broad diffraction peaks corresponding to CuFe₂O₄ along with the presence of CuO and Fe₂O₃ phases. The observed broad peaks indicate the nanocrystalline nature of the as-synthesized materials as well as the amorphous behaviour of the materials. When the sintering temperature increases to 600 °C,

Conclusions

This is an ever first attempt to synthesize CuFe₂O₄/CeO₂ nanocomposites by simple combustion method. XRD analysis confirms that the synthesized CuFe₂O₄/CeO₂ materials have the tetragonal structure and the composite behaviour. FT-IR spectra reveal the stretching vibration of the Fe single bond O and CeO bonds. The observed optical band gap values confirmed that the synthesized materials exhibit semiconducting behaviour. The nanocomposite nature of the materials has been evidenced by SEM, TEM, and HRTEM

Acknowledgements

The authors express their gratitude to Prof. A.K. Shukla, Director, CECRI, Karaikudi, India for his keen interest in this work. The authors are very much grateful to Prof. S. Selvasekarapandian (Bharathiar University, Coimbatore) for extending the facility of ac conductivity studies.

References (51)

Y.Q. Chu et al.
Electrochim. Acta
(2004)
R. Alcántara et al.
Electrochem. Commun.
(2003)
Y.N. NuLi et al.
J. Power Sources
(2005)
N. Sharma et al.
J. Power Sources
(2003)
F. Zhou et al.
J. Colloid Interf. Sci.
(2007)
L. Yuan et al.
J. Power Sources
(2006)
S.J. Bao et al.
Electrochem. Commun.
(2007)
S. Kanzaki et al.
J. Power Sources
(2007)
S.A. Needham et al.
J. Power Sources
(2006)
H.W. Ha et al.
Electrochim. Acta
(2007)

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¹: On leave from the Slovak Academy of Sciences, Watsonova 45, SK-04353 Košice, Slovakia.

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Synthesis and characterization of CuFe2O4/CeO2 nanocomposites

Abstract

Introduction

Section snippets

Experimental

Structural studies

Conclusions

Acknowledgements

Electrochim. Acta

Electrochem. Commun.

J. Power Sources

J. Power Sources

J. Colloid Interf. Sci.

J. Power Sources

Electrochem. Commun.

J. Power Sources

J. Power Sources

Electrochim. Acta

Electrochim. Acta

Electrochim. Acta

Mater. Chem. Phys.

Physica B

Mater. Sci. Eng. B

J. Magn. Magn. Mater.

Solid State Ionics

Mater. Lett.

J. Phys. Chem. Solids

J. Phys. Chem. B

Nanotechnology

Nanotechnology

Nanoletters

Nanotechnology

Nanotechnology

Synthesis and characterization of CuFe₂O₄/CeO₂ nanocomposites