School Of Basic And Applied Sciences

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    Thermophysical Assessments on Self-Assembled Tellurium Nanostructures
    (American Chemical Society, 2023-09-01T00:00:00) Sudheer, Manjima; Rani, Pinki; Patole, Shashikant P.; Alegaonkar, Prashant S.
    Thermal properties of self-assembled nanostructures are of great importance to explain the structural phase transformation phenomenon. We report on the thermophysical assessments on tellurium nanostructures (TeN) that have been prepared using a facile wet-chemical technique by admixing precursor sodium telluride (Na2TeO3) and sodium molybdate (Na2MoO4) catalysts in hydrazine hydrate solution and heated at 120 �C, over 5-7 h. The extracted products (interval: 0.5 h) were subjected to a number of spectro-microscopic techniques including thermal measurements. Under identical growth conditions, the morphology of TeN was found to be transformed from Te nanotube (TT) to Te nanoflake (TF) at 6 h. Analysis revealed that Mo participated actively during 6 h of growth time, thereby making bonds with oxygen and the Te host lattice. At the vicinity of the phase transformation, Mo acquired an interstitial position in the hexagonal motif due to enhancement in catalytic efficiency that led to the formation of MoO2- moieties, which transiently reacted with host lattices resulting in surface charging of the tubes. This, in turn, created the coalescing effect with neighboring colloidal tubes through the van der Waals interaction. Thermal properties such as thermal conductivity, effusivity, diffusivity, and specific heat studied for TeN showed prominent surface effects. The increased surface area and enhanced amount of polycrystallinity resulted in unprecedently low thermal properties of TF due to severe phonon confinement. � 2023 American Chemical Society.
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    Synergistic photophysical and electrochemical response of Te @ PANI for energy harvesting
    (Springer, 2023-01-07T00:00:00) Rani, Pinki; Jewariya, Yogesh; Haldar, Krishna Kanta; Biswas, Rathindranath; Alegaonkar, Prashant S.
    Materials with synergistic functionality are of great importance in consumer electronics. We report on the preparation and assessments of Te @ PANI composite for energy conversion and storage application. Initially, (5�15%) Te @ PANI composites were synthesized by the facile, room temperature, time and cost-effective solid-state synthesis technique followed by characterizations using Fourier transform infra-red, UV-Visible, energy dispersive spectroscopic including X-ray diffractometry and field electron scanning microscopy. Te exfoliates polymeric segments of PANI by bonding benzenoid rings through sulphonated impurity sites which have a profound impact on symmetry molecular bond vibrations. Its analysis is presented. In photophysical application, both dark and luminescent I-V measurements have been performed that showed a linear variation with minimum photo-resistance offered by 10% composite and reaching current > 10�mA under 1.5�V biased conditions. In storage response, Te @ PANI supercapacitor devices are dominating in inductive coupling over capacitive coupling by ten times. Corresponding shunt impedance is seen to be favourably lower for 10% composition, and respective charge transfer impedance has also followed identical behaviour over other classes of samples. The quality factor of the device for 10% is found to be almost twelve times better. However, at a low scan rate (10�mV/s), the presence of Te has changed the tendency of ion migration, thereby, reducing the magnitude of ion current by about three times with an increase in Te from 5 to 15%. Thus, fabricated composite demonstrated synergistic aspects of energy. � 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.