title: Ni-CeO2spherical nanostructures for magnetic and electrochemical supercapacitor applications.
abstract: The synthesis of nanoparticles has great control over the structural and functional characteristics of materials. In this study, CeO2and Ni-CeO2spherical nanoparticles were prepared using a microwave-assisted method. The prepared nanoparticles were characterized via thermogravimetry, X-ray diffraction (XRD), Raman, FTIR, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and cyclic voltammetry (CV). The pure CeO2sample exhibited a flake-like morphology, whereas Ni-doped CeO2showed spherical morphology with uniform shapes. Spherical morphologies for the Ni-doped samples were further confirmed via TEM micrographs. Thermogravimetric analyses revealed that decomposition varies with Ni-doping in CeO2. XRD revealed that the peak shifts towards lower angles for the Ni-doped samples. Furthermore, a diamagnetic to ferromagnetic transition was observed in Ni-doped CeO2. The ferromagnetic property was attributed to the introduction of oxygen vacancies in the CeO2lattice upon doping with Ni, which were confirmed by Raman and XPS. The pseudo-capacitive properties of pure and Ni-doped CeO2samples were evaluated via cyclic voltammetry and galvanostatic charge-discharge studies, wherein 1 M KOH was used as the electrolyte. The specific capacitances were 235, 351, 382, 577 and 417 F g-1corresponding to the pure 1%, 3%, 5% and 7% of Ni doped samples at the current density of 2 A g-1, respectively. The 5% Ni-doped sample showed an excellent cyclic stability and maintained 94% of its maximum specific capacitance after 1000 cycles.
authors.affiliation: Department of Physics, Alagappa University, Karaikudi-630 003, Tamil Nadu, India. gravicrc@gmail.com.
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Murugan
authors.affiliation: Department of Physics, Alagappa University, Karaikudi-630 003, Tamil Nadu, India. gravicrc@gmail.com.
authors.forename: Ganesan
authors.identifier: http://orcid.org/0000-0003-4493-1539
authors.initials: G
authors.lastname: Ravi
authors.affiliation: Department of Physics, Alagappa University, Karaikudi-630 003, Tamil Nadu, India. gravicrc@gmail.com.
authors.forename: Gandhi
authors.initials: G
authors.lastname: Vijayaprasath
authors.affiliation: Department of Physics, Alagappa University, Karaikudi-630 003, Tamil Nadu, India. gravicrc@gmail.com.
authors.forename: Somasundharam
authors.initials: S
authors.lastname: Rajendran
authors.affiliation: Department of Physics, Alagappa University, Karaikudi-630 003, Tamil Nadu, India. gravicrc@gmail.com.
authors.forename: Mahalingam
authors.initials: M
authors.lastname: Thaiyan
authors.affiliation: Department of Physics, Gandhigram Rural Institute, Gandhigram-Deemed University, Tamilnadu, India.
authors.forename: Maheswari
authors.initials: M
authors.lastname: Nallappan
authors.affiliation: Department of Physics, Gandhigram Rural Institute, Gandhigram-Deemed University, Tamilnadu, India.
authors.forename: Muralidharan
authors.initials: M
authors.lastname: Gopalan
authors.affiliation: Research Institute of Electronics, Shizuoka University, Hamamatsu-432-8011, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hayakawa