Department Of Physics

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    Effect of oxygen vacancies, lattice distortions and secondary phase on the structural, optical, dielectric and ferroelectric properties in Cd-doped Bi2Ti2O7 nanoparticles
    (Elsevier Ltd, 2021-04-27T00:00:00) Anu; Yadav, Kamlesh; Gaur, Anurag; Haldar, Krishna Kanta
    (Bi1-xCdx)2Ti2O7 (x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10 and 0.12) nanoparticles are synthesised using the co-precipitation method. The prepared samples show pyrochlore phase formation except for x = 0.02 and 0.08, where Bi4Ti3O12 appears as a secondary phase. The crystallite size and unit cell volume decrease while the strain and dislocation density increase with an increase in Cd-doping. The vibrational bands corresponding to Cd?O and C[dbnd]O are red-shifted, while the H[sbnd]O[sbnd]H bending band is blue-shifted with increasing Cd-doping. The band gap energy for x = 0.00 is found to be 1.78 eV. It increases with an increase in �x� up to 0.06 and then decreases with a further increase in �x� except for x = 0.02 and x = 0.08. The impedance data show non-Debye type relaxation. The pyrochlore phase is found to be non-ferroelectric. However, the samples with x = 0.02 and x = 0.08 having the secondary phase (Bi4Ti3O12) are ferroelectric. � 2021 Elsevier Ltd
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    A Protein and Membrane Integrity Study of TiO2 Nanoparticles-Induced Mitochondrial Dysfunction and Prevention by Iron Incorporation
    (Springer, 2021-03-31T00:00:00) Barkhade, Tejal; Mahapatra, Santosh Kumar; Banerjee, Indrani
    The paper assessed the toxic effect of titanium dioxide (TiO2) nanoparticles (NPs) on isolated mitochondria and its dysfunction prevention after Iron (Fe) incorporation. TiO2 and Fe content TiO2 NPs were synthesized and characterized using XPS, PL spectroscopy, and TEM. The nanostructure interaction with isolated mitochondria was investigated using circular dichroism (CD) confocal microscopy, flow cytometry, atomic force microscopy (AFM), surface-enhanced Raman spectroscopy (SERS), and FT-IR spectroscopy via nonspecific pathway. Fe content TiO2 NPs helps to control the dissolution rate of parent nanomaterial of TiO2 on the mitochondrial membrane. Confocal micrographs and flow cytometry results confirmed that Rhodamine 123 dye intensity get increased after interaction with Fe content TiO2 NPs which states the integrity of the mitochondrial membrane. AFM results revealed that TiO2 induces the swelling of mitochondrial tubules and also impaired the mitochondrial structure, whereas Fe content TiO2 NPs interaction prevents the impairment of mitochondrial tubules. The denaturation of a membrane protein by TiO2 interactions was observed through CD Spectroscopy. Further, nano-bio-interface study was performed using SERS, through shifting and extinct of peaks affiliated to membrane proteins and lipids. However, Fe content TiO2-treated samples showed a significant increase in the membrane potential of mitochondria via flow cytometry results. Graphic Abstract: [Figure not available: see fulltext.] � 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
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    Iron content titanium dioxide nanoparticles as exogenous contrast agent for tissue imaging using swept-source optical coherence tomography
    (American Institute of Physics Inc., 2021-01-08T00:00:00) Barkhade, Tejal; Indoliya, Abhishek; Poddar, Raju; Mahapatra, Santosh Kumar; Banerjee, Indrani
    Ex vivo tissue imaging was performed by swept-source optical coherence tomography (SS-OCT) using titanium dioxide (TiO2) and Fe content TiO2 nanoparticles (NPs). The comparative effects of TiO2 and Fe content TiO2 NPs in terms of contrast enhancement, penetration, scattering, and accumulation in the chicken breast tissue have been monitored at different exposure times. Powder NP samples were synthesized using the sol-gel method, and characterization was carried out via transmission electron microscopy, x-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy techniques. Fe incorporation in the TiO2 matrix reduces its toxic effect on tissue skin and produces a safe exogenous contrast agent, which is analyzed by SS-OCT. The scattering coefficients and contrast to noise ratio of the tissues with and without NPs were determined to study the imaging efficacy. The improvement in the coefficient was observed with an increase in the exposure time of NPs. Nano-TiO2 has shown the ability to penetrate within the tissue layer up to 780 ?m while Fe content TiO2 NPs samples showed the lowest rate of penetration up to 210 ?m after a 30 min time interval. � 2021 Author(s).
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    Preparation and characterization of cathode material for energy storage/conversion devices
    (Central University of Punjab, 2016) Sangeeta
    Metal Matrix Composites (MMCs) have evoked an intense interest in recent times for potential applications in marines, aerospace and automotive industries owing to their larger strength to weight ratio and high-temperature resistance. We have synthesized nanocomposites of (LaMnO3)1-x/(TiO2)x and (Fe2O3)1-x/(Cr2O3)x with varying concentration of TiO2 (x = 0.0-0.4) and Cr2O3 (x = 0.0-1.0). In the first chapter, includes the introduction of the metal matrix nanocomposites and their advantages. In the second chapter we have discussed about the literature review and knowledge gap. Chapter 3 involves the experimental procedure and discussion of different characterization techniques (XRD, FTIR, FESEM and EDS) used to study the prepared sample. Chapter 4 involves result and discussions obtained by characterizing the prepared sample. XRD analysis confirms the orthorhombic structure of (LaMnO3)/(TiO2) and rhombohedral structure (Fe2O3)/(Cr2O3) nanocomposites. From FESEM we have calculated the particle size for pure (LaMnO3) is 1 m and for (LaMnO3)1-x/(TiO2)x and its value decreases from 19.99- 16.91 nm with increase the concentration of TiO2 from x = 0.1-0.4. We have also calculated the band gap and refractive index from the FTIR analysis and found that gradual increase in band gap from 2.1-2.26 eV and decrease in refractive index from 2.67-2.62 as the concentration of TiO2 increases (x = 0.0-0.4). The (Fe2O3)/(Cr2O3) iv nanocomposites showed that increase in band gap 2.1-3.0 eV with decrease in particle size from 70.71-49.24 nm and refractive index from 2.67-2.44 as the concentration and Cr2O3 increases (x = 0.0-1.0.) The FTIR confirms all the functional groups present in the synthesized samples. The main application of these as- synthesized nanocomposites is photocatalysis.
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    Titania sensitized with SPADNS dye for dye sensitized solar cell
    (Springer New York LLC, 2016) Didwal, P.N.; Pawar, K.S.; Chikate, P.R.; Abhyankar, A.C.; Pathan, H.M.; Devan, R.S.
    Synthesis of anatase TiO2 nanoparticle with diameter about 25?nm is carried out by using chemical method and powder of TiO2 nanoparticle is pasted on fluorine doped tin oxide (FTO) coated glass by doctor blade. New organic SPADNS dye (C16H9N2Na3O11S3) is used first time to make the dye-sensitized solar cells (DSSC). Cell were constructed by using SPADNS dye loaded wide band gap anatase TiO2 nanoparticle on FTO coated glass as photo-anode, polyiodide as electrolyte, and platinum coated FTO as counter electrode. SPADNS dye was made from organic reagent which is low cost and easy available in market. Better adsorption of SPADNS dye on anatase TiO2 film is due to porous nature of TiO2. This better adsorption gives more transportation of electron from dye to TiO2 which increase the efficiency of solar cell. Although SPADNS dye is the first experiment with TiO2 nanoparticle for DSSC, it gives photocurrent (short-circuit current density) 1.04?mA/cm2, open-circuit voltage 0.59?V, with 0.9?% efficiency under 10?mW/m2 LED. ? 2016, Springer Science+Business Media New York.