Shivaji University

About: Shivaji University is a education organization based out in Kolhāpur, Maharashtra, India. It is known for research contribution in the topics: Thin film & Scanning electron microscope. The organization has 3078 authors who have published 5295 publications receiving 115397 citations.

Honeycomb-layer structured Na3Ni2BiO6 as a high voltage and long life cathode material for sodium-ion batteries

Abstract: The need to find sodium ion battery (SIB) cathodes with high voltage, capacity and improved cycle life has stimulated research on sodium containing layered transition metal oxides. With this perspective, the electrochemical properties of highly ordered, honeycomb layered Na3Ni2BiO6 with a monoclinic superstructure are explored as a cathode material in SIBs. It has been demonstrated that Na3Ni2BiO6 delivers a discharge capacity of 106 mA h g−1, having high voltage plateaus at 3.50 and 3.25 V, with marginal capacity fading after 50 cycles. Operando X-ray diffraction studies during charging/discharging reveal two reversible two-phase transition mechanisms (initial O3 phase → P3 intermediate phase → O1 final phase) during sodium extraction. Ex situ X-ray absorption spectroscopy reveals the charge compensation mechanism for the reversible Ni3+/Ni2+ as an active redox couple while Bi5+ being inactive during cycling. Extended X-ray absorption fine structure analysis shows highly reversible local structural changes around both Ni and Bi atoms occurring during electrochemical cycling. In addition, unique local structure changes especially around Ni atoms due to the honeycomb ordering and size mismatch between Ni2+ and Bi5+ ions are revealed by EXAFS analysis during charging and discharging, which is quite different from the local structure changes in regular layer structured NaMO2 (M = transition metals) cathode materials. The present results suggest that honeycomb layered metal oxides with the general formula, Na3M(II)2M(V)O6, can be considered as candidates for high voltage and long life cathode materials for SIBs.

Electrochromic properties of dandelion flower like nickel oxide thin films

Abstract: This report highlights a one pot, surfactantless, template free approach to grow novel dandelion flower like nickel oxide (NiO) thin films composed of nano-flakes with a highly porous structure Good transmittance modulation, fast response time and excellent coloration efficiency make them a potential electrode material for electrochromic devices

Room temperature LPG sensor based on n-CdS/p-polyaniline heterojunction

Abstract: In the present work, room temperature (300 K) liquefied petroleum gas (LPG) sensor based on n-CdS/p-polyaniline thin film heterojunction has been fabricated using simple inexpensive electrodeposition technique. The CdS and polyaniline films were characterized for their structural and surface morphological properties and LPG sensing performance of n-CdS/p-polyaniline heterojunction was studied. The X-ray diffraction (XRD) study revealed polycrystalline cubic phase for CdS films whereas the polyaniline films exhibited amorphous structure. Morphological analysis using field-emission scanning electron microscopy (FESEM) of the junction cross-section revealed the formation of a diffusion-free interface. The room temperature gas response towards N 2, CO 2 and LPG was investigated and found to exhibit high response towards LPG as compared to N 2 and CO 2. The maximum gas response of 80% was achieved with 95% stability for n-CdS/p-polyaniline heterojunction upon exposure of 1040 ppm LPG at room temperature.