Abhay D. Deshmukh

Conducting polymers and their inorganic composites for advanced Li-ion batteries: a review

Conducting polymers are promising materials for organic–inorganic hybrid composites in lithium-ion batteries due to their electrical conductivity and high coulombic efficiency and are able to be cycled hundreds or thousands of times with only slight degradation. Inorganic compounds generally possess good lithium storage properties but lack the conductivity and cyclability required for commercial application. Therefore, these problems need to be overcome before they can be used as effective electrodes. Over the past few years, conductive polymers in combination with inorganic compounds have attracted great interest as promising matrices for the construction of lithium-ion batteries. Because conducting polymers can interact synergistically with inorganic compounds, noteworthy improvements in electrode lifetime, rate capabilities, and voltage, as well as mechanical and thermal stability, have been achieved. This review covers recent advances in synthetic methods and functions of conducting polymers in hybrid composites and their application in lithium-ion batteries. We then present a comparison of other synthetic methods for new research and development in batteries. A brief appraisal of avenues for future developments in this area is also presented.

Luminomagnetic bifunctionality of Mn2+-bonded graphene oxide/reduced graphene oxide two dimensional nanosheets

Herein, we report the luminomagnetic bifunctional properties of two-dimensional (2D) Mn(2+) bonded graphene oxide (GO)/reduced graphene oxide (RGO) nanosheets synthesized using a facile route of oxidation followed by a solvothermal reduction method. Photoluminescence (PL) studies (excited by different wavelengths) revealed that the resonant energy transfer between Mn(2+) and sp(3)/sp(2) clusters of GO/RGO is responsible for the enhancement of emissions. Moreover, pH-sensitive PL behaviors have also been investigated in detail. The ferromagnetic behavior is believed to arise due to defects in Mn(2+) bonded GO composites. Thus, present reduction method provides a direct route to tune and enhance the optical properties of GO and RGO nanosheets bonded with Mn(2+) ions, which creates an opportunity for various technological applications.

Tunable luminescence from two dimensional BCNO nanophosphor for high-contrast cellular imaging

Rare-earth free and biocompatible two dimensional carbon based boron oxynitride (2D BCNO) nanophosphors were synthesized using facile auto-combustion of inexpensive compounds such as urea, boric acid and polyethylene glycol at ambient atmosphere and relatively low temperatures. The surface morphology and microstructure images indicate that the nanophosphor has 2D layered structures and analogous mixed hexagonal lattices of boron nitride (BN) and graphene (C). The nanophosphor exhibits a single, distinct and broad photoluminescence emission and this emission colour can be easily tuned from violet to deep red by varying the amount of boron/carbon content. The time-resolved and photoluminescence spectroscopic results indicate that B–O act as luminescence centers, which are responsible for the tunable luminescent properties while carbon impurities induce energy levels in the band gap of 2D BCNO nanophosphors. These tunable and biocompatible luminescent nanophosphors are used for in vitro high-contrast cellular imaging of HeLa cells derived from human cervical cancer cells as well as in vivo imaging in C57BL/6J mice. Hence, these novel multi-colour emitting nanophosphors provide a paradigm shift in rare-earth free biocompatible nanoprobes for next generation high-contrast in vitro and in vivo imaging applications.

Alteration of the electronic structure and the optical properties of graphitic carbon nitride by metal ion doping

The photoluminescence quenching of graphitic carbon nitride (GCN) was systematically investigated with the doping of transition metal ions. The photoluminescence spectra of metal doped and pristine GCN were monitored and the trend of quenching efficiency was found to be Cu2+u202f>u202fCo2+u202f>u202fMn2+. Interestingly, with the increasing doping concentration of different metal ions simultaneous red shift and luminescence quenching was determined in the photoluminescence spectra as well as increased absorption tail in longer wavelength hence enhancement in the bandgap. The change in the optical properties could be mainly due to structural reconstruction and doping induced electronic redistribution is discussed.

Effect of Cryo-Ageing at Liquid Nitrogen Temperature and Subsequent Thermal-Annealing on the Interface of Talc Filled Polypropylene with Different Particle Size

Polypropylene (PP) based materials are widely used because of their low cost, good processability and good balance of properties but its low stiffness and strength greatly hinders its even wider utilization. In order to overcome this, PP is reinforced with different fillers. In composites; the issue of interface between the filler and matrix is of importance. Thus in the present paper, the effect of cryo-ageing and subsequent thermal-annealing on the PP-talc filled composites have been studied to monitor its effect on the interface. The composites with talc of different particle sizes are examined for mechanical and structural properties after treatment. The mechanical properties are evaluated by testing its tensile strength and wear performance, whereas, the study of structural properties by FTIR and SEM reveals some structural changes. These results have further been discussed and evaluated to find out the effect of these treatments on interface of various selected talc filled PP composite.

Photoluminescence in Sm3+ doped Ba2P2O7 phosphor prepared by solution combustion method

In this paper, Sm3+ doped Ba2P2O7 phosphors were synthesized via a Solution combustion method. The crystalxa0structure of the phosphor was characterized by XRD. Orange-red emission was observed from ...

Green light emitting curcumin dye in organic solvents

In this modern world, the demand for the white light emission has increased because of its wide applications in various display and lighting devices, sensors etc. This white light can be produced by mixing red, green and blue lights. Thus this green light can be produced from the plant extract i.e., Turmeric. Curcumin is the essential element present in turmeric to generate the green light. The Photoluminescence (PL) emission is observed at 540u2005nm at 380nm excitation. This method of generating green light is very simple, cost effective and efficient when compared to other methods.In this modern world, the demand for the white light emission has increased because of its wide applications in various display and lighting devices, sensors etc. This white light can be produced by mixing red, green and blue lights. Thus this green light can be produced from the plant extract i.e., Turmeric. Curcumin is the essential element present in turmeric to generate the green light. The Photoluminescence (PL) emission is observed at 540u2005nm at 380nm excitation. This method of generating green light is very simple, cost effective and efficient when compared to other methods.

Inflorescence type morphology and mirror–mist–hackle pattern in tensile fractograph of MWCNT/PBT nano-composites

Abstract Polybutylene terephthalate (PBT) is extensively used for automobile and aircraft components, which are prone to continuous damage and, thus, are expected to have superior mechanical properties. With the aim of achieving this, carbon nanotube (CNT) reinforced polymer composites are steadily gaining importance. To address this area, the present study deals with the fabrication and characterization of PBT reinforced with multi-walled CNTs (0.1 to 0.5 wt.%) and its effect on tensile strength. The strength of the composite increased at first and later reduced marginally with increasing filler content. A study of fractured surfaces of the composites showed formation of CNT–polymer inflorescence type morphology which indicated that the nanotubes within the polymer matrix act as an anchor for carrying and distributing the load during fracture. This demonstrates appreciable interfacial bonding between polymer matrix and the CNTs.

Two-Dimensional Double Hydroxide Nanoarchitecture with High Areal and Volumetric Capacitance

The development of high volumetric or areal capacitance energy storage devices is critical for the future electronic devices. Hence, the hunting for next-generation electrode materials and their design is of current interest. The recent work in the two-dimensional metal hydroxide nanomaterials demonstrates its ability as a promising candidate for supercapacitor due to its unique structure and additional redox sites. This study reports a design of freestanding high-mass-loaded copper-cobalt hydroxide interconnected nanosheets for high-volumetric/areal-performance electrode. The unique combination of hydroxide electrode with high mass loading (26 mg/cm2) exhibits high areal and volumetric capacitance of 20.86 F/cm2 (1032 F/cm3) at a current density of 10 mA/cm2. This attributes to the direct growth of hydroxides on porous foam and conductivity of copper, which benefits the electron transport. The asymmetric supercapacitor device exhibits a high energy density of 21.9 mWh/cm3, with superior capacitance retention of 96.55% over 3500 cycles.

Efficient Red Downshifting in Layered Structure: A Broad Spectral Converter for Enhancing Photo-response of Solar Cell

Spectral convertors are promising materials for solar cells as they engineered the band gap necessary for suppressing the losses. Existing spectral convertors have small stokes shift which exerts re-absorption losses due to the overlap of spectrum and limits light catching ability. Here we present large stoke shift chromium doped rhombohedral Al2O3: Cr3+ as a spectral convertor from UV–VIS to red region as single doped with maximum coverage of solar spectrum in UV region. The large stoke shifts in red region around 694xa0nm originate from 2Eg to 4A2g and broad absorption originates from