Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Nagaraja, H.S.Subject: search.filters.subject.Ferrite

Search Results

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    Microwave assisted growth of stannous ferrite microcubes as electrodes for potentiometric nonenzymatic H2O2 sensor and supercapacitor applications
    (Elsevier Ltd, 2016) Bindu, K.; Sridharan, K.; Ajith, K.M.; Lim, H.N.; Nagaraja, H.S.
    Electrochemical sensors and supercapacitors are two noteworthy applications of electrochemistry. Herein, we report the synthesis of SnFe2O4 microcubes and Fe2O3 nanorods through a facile microwave assisted technique which are employed in fabricating the electrodes for nonenzymatic hydrogen peroxide (H2O2) sensor and supercapacitor applications. SnFe2O4 microcubes exhibited an enhanced specific capacitance of 172 Fg?1 at a scan rate of 5 mVs?1 in comparison to Fe2O3 nanorods (70 Fg?1). Furthermore, the H2O2 sensing performance of the fabricated SnFe2O4 electrodes through chronopotentiometry studies in 0.1 M PBS solution (at pH 7) with a wide linear range revealed a good sensitivity of 2.7 mV ?M?1 ?g?1 with a lowest detection limit of 41 nM at a signal-to-noise ratio of 3. These results indicate that SnFe2O4 microcubes are excellent materials for the cost effective design and development of efficient supercapacitors as well as nonenzymatic sensors. © 2016 Elsevier Ltd
  • No Thumbnail Available
    Item
    Influence of cations on the dielectric properties of spinel structured nanoferrites
    (Institute of Physics Publishing helen.craven@iop.org, 2019) Bindu, K.; Ajith, K.M.; Nagaraja, H.S.
    MFe2O4 (M: Fe, Zn, Ni and Sn) nanoparticles were prepared using single step hydrothermal method. Their structural, compositional and dielectric properties have been studied to investigate the effect of cations on spinel ferrites. XRD confirms the spinel structure of the samples with substitution of Zn, Ni and Sn in the lattice sites of Fe. FTIR spectra of all samples have characteristic ?1 and ?2 bands. SEM and EDS mapping show uniform distribution of cations throughout the samples. ZnFe2O4 and SnFe2O4 have higher ac conductivity and dielectric constant than that of Fe3O4 and NiFe2O4, which can be attributed to the different cationic distribution in the spinel structure. © 2019 IOP Publishing Ltd.
  • No Thumbnail Available
    Item
    Influence of cations in MFe2O4 (M: Fe, Zn, Ni, Sn) ferrite nanoparticles on the electrocatalytic activity for application in hydrogen peroxide sensor
    (Institute of Physics Publishing helen.craven@iop.org, 2019) Bindu, K.; Nagaraja, H.S.
    Hydrothermally prepared MFe2O4 (M: Fe, Zn, Ni and Sn) nanoparticles have been characterized by XRD, SEM and BET. The ferrite nanoparticles have been tested for their electrocatalytic activity and application towards the reduction and sensing of hydrogen peroxide using cyclic voltammetry and chronoamperometry techniques. ZnFe2O4 and SnFe2O4 reveal superior H2O2 sensing performance than Fe3O4 and NiFe2O4, which can be attributed to the lower redox potential of Sn2+/Sn4+ couple, lower charge-transfer resistance and higher specific surface area. ZnFe2O4 and SnFe2O4 have a sensitivity of 4.411 and 3.915 ?AmM-1 ?g-1, respectively, which is greater than that of Fe3O4 (0.434 ?AmM-1 ?g-1) and NiFe2O4 (0.644 ?AmM-1 ?g-1). SnFe2O4 has the lowest limit of detection (2.6 (M) with good selectivity towards H2O2 in the presence of other interference agents. © 2019 IOP Publishing Ltd.
  • No Thumbnail Available
    Item
    Synergistic boost in Fe3O4 anode performance for li-ion batteries via Zn and Cu double doping and multi-walled carbon nanotube composite integration
    (Elsevier B.V., 2024) Kumar, A.; Mukesh, P.; Lakshmi Sagar, G.; Hegde, A.; Nagaraja, H.S.
    In this study, a novel nanocomposite material comprising pure Fe3O4 (FO), doped Zn0.5Cu0.5Fe2O4-3 (ZCFO-3), and Zn0.5Cu0.5Fe2O4-3@ Multi-walled carbon nanotube (ZCFO-3@MWCNT) nanocomposite material is carefully prepared using a simple one-step hydrothermal process. Comprehensive surface and morphological analysis are conducted using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and High-resolution transmission electron microscopy (HRTEM), while compositional studies are investigated through Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrochemical performance is fully analyzed through Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), rate capability tests, discharge/charge capacity, and cyclic stability evaluations. Among these three nanomaterials, ZCFO-3@MWCNT nanocomposite at 100 mA g−1 current density reveals the best performance, with a discharge capacity of 1974 mAh g–1, ZCFO-3 and FO reveal 1340 mAh g–1 and 1317 mAh g–1 respectively. After 800 cycles at 500 mA g−1 current density, ZCFO-3@MWCNT stays strong with a discharge capacity of 646 mAh g–1, while ZCFO-3 manages only 362 mAh g–1 and FO only 111 mAh g–1. After 1200 cycles at 500 mA g−1, the nanocomposite still delivers 518 mAh g–1. This study suggests that ZCFO-3@MWCNT could be a promising anode material for lithium-ion batteries. © 2024 Elsevier B.V.