IR@CGCRI - Central Glass and Ceramic Research Institute (CSIR)
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Engineering Multifunctionality in MoSe2 Nanostructures Via Strategic Mn Doping for Electrochemical Energy Storage and Photosensing
No full textTo achieve advanced functionalities in nanostructured MoSe2 for enhanced electrochemical charge storage and improved photosensing, here we propose an effective strategy, i.e., the substitutional doping of the heteroatom Mn. We achieve a 313% increase in specific capacitance for 6.2% of Mn doping compared to pristine MoSe2 at the scan rate of 5 mV/s in a three electrode configuration. For a two-electrode arrangement, also superior charge-storage performance is noted. The enhanced electrode performance can be attributed to the increase of electrical conductivity arising due to an increase of electron density for the n-type nature of Mn doping realized via an X-ray photoelectron spectroscopy study and density functional theory calculation. The latter one also unveils that Mn doping introduces catalytically active sites by disrupting homogeneous charge distribution over the topology of the MoSe2 basal plane contributing to better charge-storage performance. Mn doping-induced shift in the Fermi level of MoSe2 toward the conduction band also minimizes the contact barrier height signifying its improved capabilities for a photosensor device. Additionally, Mn doping causes alleviation of the charge-recombination process resulting in increase of photocarrier separation. As a result, we observe a 187% enhancement in the photocurrent and significantly higher responsivity and detectivity for 6.2% Mn-doped MoSe2 than its pristine counterpart. Our proposed doping strategy to modulate charge storage as well as photoresponse properties demonstrates high potential for MoSe2 along with other two-dimensional transition-metal dichalcogenides in developing next-generation energy-storage and optoelectronic devices
Unveiling thereinforcement potentiality of MWCNTs architecture towards the improvement of microstructural vis-a-vis mechanical and thermo-mechanical properties of pressureless sintered MgAl2O4 spinel ceramic composite
No full textThe study presented in this work focuses on the preparation of composites made of multi-walled carbon nanotubes (MWCNTs) and magnesium aluminate spinel through a pressureless sintering technique. The effects of sintering temperature and MWCNTs content on the densification behavior and mechanical properties of the composite were investigated in detail. The results revealed that the composite exhibited improved densification behavior, enhanced mechanical performance and decent control at the micro -structural refinement with increasing MWCNTs content up to 0.75 wt%. The superior mechanical properties obtained in case of sintered composite were attributed to the synergetic toughening mechanisms involving the fiber pull out, cracks bridging and cracks deflection effects of reinforcing phases, observed as a resultant effect of strong interfaces with the matrix phase. The crystalline structural arrangement obtained from the XRD and Raman spectral analysis of the composites structure also satisfies the attainment of the promising reinforcement potential of the nanotubular structure. Most importantly, the study also exemplified the subsidiary interference of a surface decorative coating on the MWCNTs structure with the MgAl-binary oxide network. The strategic grafting of the oxide protective shell and the consequent development of a robust interfacial bridging network between the matrix and reinforcement phase regulated the energy dissipation characteristic for fiber debonding. This, in turn, restricted the crack growth phenomenon during mechanical loading, and thereby ultimately contributing to the enhanced fracture toughness, reduced thermal expansion co-efficient and augmented thermo-mechanical performance of the evolved spinel-based composite structure & COPY; 2023 Elsevier B.V. All rights reserved
Morphotropic Phase Boundary-Assisted Lead-Free BaTiO3/PDMS Composite-Based Hybrid Energy Harvester: A Portable Power Source for Wireless Power Transmission
No full textHere, in this present work, the developmentof a lightweight, flexiblehybrid energy harvester using a composite BaTi0.89Sn0.11O3 (BTS)/polydimethylsiloxane (PDMS) has beenproposed. A significantly enhanced output performance of hybrid energyharvester (HEH) was achieved by strategically coupling the piezoelectriceffect with the triboelectric output. Thus, multiphase coexisted BTSparticles as confirmed by the structural and dielectric properties,with a high value of d (33) coefficient & SIM;412pC/N, were used as filler for the functional layer (PDMS) of the device.The hybrid energy harvesting device can harvest a maximum voltageof & SIM;358 V with an instantaneous power density of 1.08 mW/cm(2) from human finger imparting (force & SIM; 100 N, frequency & SIM; 4 Hz). The fabricated device harvests energy from handwritingand differentiates fine patterns of different letters by using itas a writing pad. In addition to that, a wireless system utilizingan inductor-based resonant coupling mechanism was developed for wirelesspower transmission. The easy processability, flexibility, high outputperformance, and alignment toward a power source for wireless powertransmission make the fabricated HEH device a promising candidatefor various applications for portable smart flexi-electronics
Assessment of a Novel Chemical Analysis Technique to Investigate Cesium in Glass by Developing Cesium Bismuth Iodide
No full textThe present work aims at qualitative investigation of cesium content present in a glass. A glass comprising (wt%) Cs2O(30)-SiO2(35)-Na2O(7)-SnO2(4)-Z nO(24) was prepared in a conventional heating furnace. A novel method was developed adopting gravimetric analysis of cesium content in the glass samples using Dragendorff's reagent, leading to formation of Cs3Bi2I9 crystal (salt). Experimental methods were examined to purify the salt. Qualitative analysis was performed on Cs3Bi2I9 crystal with FESEM-EDX and XRD. Up to & SIM;93% pure Cs3Bi2I9 could be synthesized. Quantitative studies were performed with standard cesium solution prepared with Cs2CO3 with varying compositions of cesium within 1000 to 3000 ppm. Weight of salt produced was concluded to be strongly related to the cesium content present in the glass solution
Carbon nanotube-glass composite with high dielectric constant and low dielectric loss for energy storage device applications
No full textSingle walled carbon nanotubes (SWCNT) have been embedded as electrically conductive filler inside a borosilicate glass matrix to fabricate SWCNT-glass composites with enriched dielectric properties. The composite shows significantly increased dielectric constant (& epsilon;') at room temperature which is 103 times higher than that of the base glass. Dielectric loss of the SWCNT-glass composite is also observed to be relatively low especially at higher frequencies. In correlation with the morphology, high dielectric constant of the composite is explained by the formation of microcapacitor networks of the carbon nanotubes and Maxwell-Wagner-Sillars polarization at nanotube/glass interface
Advancing insights towards electrocatalytic activity of La/ Ba-Sr-Co-Fe-O-based perovskites for oxygen reduction & evolution process in reversible solid oxide cell
No full textElectrocatalytic activity of La/Ba-Sr-Co-Fe-O-based mixed ionic and electronically conducting (MIEC) perovskites has been studied for selective oxygen reduction (ORR) and evolution (OER) processes applicable in Reversible Solid Oxide Cell (R-SOC). XPS study establishes scavenging of oxygen vacancy in LSCF and generation of the same in BSCF. BSCF enables faster oxygen ion transport and is correlated with lower frontier molecular orbital (FMO) energy gap of 1.18 eV derived from density functional theory (DFT). Relatively higher AEFMO(Absolute) 1.75 eV in LSCF accounts for higher charge transfer. Amperometric measurements @800celcius in asymmetric cell configuration exhibit lowest time-dependent current loss of 0.019 mA.h-1 & 0.035 mA.h-1 for BSCF & LSCF under applied anodic (+0.8 V) and cathodic potentials (-0.8 V) for 200 h with respective surface resistances (Rs) of 0.19 l.cm2 and 0.081 l.cm2. H2 flux of 0.4Nl.h-1.cm-2 obtained with BSCF, establishes its effectivity as OER whereas LSCF is found to be more selective in ORR
Squeeze Film Effect in Surface Micromachined Nano Ultrasonic Sensor for Different Diaphragm Displacement Profiles
No full textIn the present paper, we have analytically explored the small variations of the local pressure in the trapped air film of both sides of the clamped circular capacitive micromachined ultrasonic transducer (CMUT), which consists of a thin movable membrane of silicon nitride (Si3N4). This time-independent pressure profile has been investigated thoroughly by solving the associated linear Reynold's equation in the framework of three analytical models, viz. membrane model, plate model, and non-local plate model. The solution involves Bessel functions of the first kind. The Landau-Lifschitz fringing technique has been assimilated to engrave the edge effects in estimation of the capacitance of CMUT, which should be considered in the micrometer or lesser dimension. To divulge the dimension-based efficacy of the considered analytical models, various statistical methods have been employed. Our use of contour plots of absolute quadratic deviation revealed a very satisfactory solution in this direction. Though the analytical expression of the pressure profile is very cumbersome in various models, the analysis of these outputs exhibits that the pressure profile follows the displacement profile in all the cases indicating no viscous damping. A finite element model (FEM) has been used to validate the systematic analyses of displacement profiles for several radii and thicknesses of the CMUT's diaphragm. The FEM result is further corroborated by published experimental results bearing excellent outcome
Facile synthesis of electrospun antibacterial bioactive glass based micronanofibre (ABGmnf) for exalted wound healing: In vitro and in vivo studies
No full textRecently, bioactive glass has shown an incredible potential to address the assortment of chronic wounds including diabetic and venous ulcers. In this regard, the textural properties of bioactive glass (BG)-based micronanofibre, which are analogous to the fibrin clot that aggregates platelets, provide advantages that support the coagulation cascade and subsequent soft tissue regeneration by providing mechanical support and a source of various therapeutic ions. In this correspondence, we synthesized a binary composition comprising (70-x) mol% SiO2, (30-y) mol% CaO, 1 < x < 5 mol% B2O3 and 0.001< y < 0.1mol% Ag2O composition (ABGmnf) via sol-gel method followed by fabrication of the electrospun fibres, and state-of-art characterizations, XRD, FTIR, and FESEM-EDXalong with biological studies including in-vitro cytocompatibility, 2D wound healing, antibacterial activities by determination of minimum inhibitory concentration (MIC). In addition, the concentration of proinflammatory cytokines (TNF-a and IL-6) and various hematological, biochemical, and histopathological parameters were used to establish the in vivo biocompatibility. The in vivo wound healing assay, which demonstrated rapid wound closure, was then examined. ABGmnf's excellent cyto-and biocompatibility could be demonstrated by the above findings alongwith the lack of host-material interaction, as well
Mixed perovskites (2D/3D)-based solar cells: a review on crystallization and surface modification for enhanced efficiency and stability
No full textSolar cells based on a three-dimensional (3D) crystalline perovskite framework exhibit desired photoconversion efficiency. However, 3D perovskites are prone to surface defects, leading to severe Shockley-Read-Hall (SRH) recombination and insufficient interactions between components, resulting in lower efficiency and stability. In contrast, two-dimensional (2D) perovskites have comparatively better excellent stability in hot and humid environments but suffer from lower efficiency. Recently, researchers reported that surface passivation of 3D perovskite by 2D perovskite improves the stability of solar cells without compromising their efficiency. In this review, the recent advances in surface modification of three-dimensional perovskites using two-dimensional perovskites are discussed. The crystal structures, photoelectric properties, and surface passivation strategies of 2D/3D perovskite solar cells with different components are systematically presented. Finally, the prospect of using two-dimensional perovskite passivation technology to further improve photovoltaic performance is discussed
Investigation of local structure and phase transformation in Ce-doped barium titanate and correlation with electrical properties
No full textBaTiO3-based materials are used as the replacement for lead-based perovskite materials for its wide dielectric applications. But the substitution of different doping elements in pure BaTiO3 drastically affects the microstructure, phase transition behavior and electrical properties. In the present work, local structure, phase transformation and dielectric behavior of BaCexTi1-xO3 (BCT) ceramics were studied for compositions x = 0.02, 0.05 and 0.1. A diffuse phase transition from orthorhombic to cubic via tetragonal in BCT with increasing Ce content was observed. An increase in particle size with Ce doping concentration was observed in FESEM images. Spherical and cuboid-shaped particle in the order of 80-150 nm was observed in transmission electron microscopic (TEM) images. RAMAN spectra confirm the tetragonal to cubic phase transition. Local structural and phase transformation behavior was obtained from laboratory-based PDF and XRD, respectively. Change in PDF was observed due to an increase in Ce doping. Dielectric properties decreased for Ce mole fraction of x = 0.1