Synthesis, Characterization and Bio-Medical, Magnetic Data Storage and Environmental Applications of Co@SiO2 Core/Shell Nanoparticles

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue IX, September 2018 | ISSN 2321–2705

Synthesis, Characterization and Bio-Medical, Magnetic Data Storage and Environmental Applications of Co@SiO₂ Core/Shell Nanoparticles

J. Alimunnisa^*1, K. Ravichandran² and K. S. Meena¹

¹PG and Research Department of Chemistry, Queen Mary’s College (A), Chennai-600 004, India
² Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025, India
*Corresponding author email: J. Alimunnisa

Abstract: – This paper discusses about the Co core – SiO₂ shell (Co@SiO₂) nanoparticles prepared by the modified Stöber method. Phase formation and properties of the particles were studied using X-ray diffraction, field emission scanning electron microscopy (FESEM) with energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), impedance spectroscopy (IS), microbial and photo catalytic activities. The insulating layer of SiO₂ shell thickness can block nanoparticles from growing up. Two different phases of cubic structure (f. c. c) for Co and Tetragonal structure of shell SiO₂ were identified from particles. FESEM morphology shows the octahedral symmetric crystal for 0.5 and 1 ml concentration, which is highly porous, well crystallined nature. EDS and XPS measurement peaks show the presence of Co, Si and O elements and confirm the formation of core-shell structure. Paramagnetic for 0.5 ml and diamagnetic behaviour for 1 ml concentration were obtained from VSM measurements. Impedance studies of the sample show very high resistance that is only due to SiO₂ shell. Synthesized nanoparticle having controllable grain size, shape and magnetic property is a suitable candidate for many biomedical, storage, anti-corrosion resistance and environmental applications.

Key words: Magnetic nanoparticle, Stöber method, core- shell nanoparticle, XRD, VSM, X- ray photoelectron spectroscopy.

I. INTRODUCTION

Unique properties small magnetic metal core, oxide shell (core@shell) nanoparticles have recently been grabed the attention of researcher. They have several potential applications in the field of magnetic resonance imaging (MRI) where the ferromagnetism or super paramagnetic properties of the particles provide effective contrast imaging for medical diagnosis, magnetic fluid hyperthermia, controlled drug delivery systems, biosensors, catalysis and energy conversion [1-17].

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