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Author

Mayank Pandey

Other affiliations: VIT University
Bio: Mayank Pandey is an academic researcher from Christ University. The author has contributed to research in topics: Graphene & Dielectric. The author has an hindex of 10, co-authored 29 publications receiving 261 citations. Previous affiliations of Mayank Pandey include VIT University.

Papers
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Journal ArticleDOI
15 Dec 2020-Fuel
TL;DR: In this article, a review article describing all possible directions related to such typical natural resources and application of their carbon derivatives/products for better electrochemical properties is presented, which will be very helpful for future research work in the field of carbon electrode materials derived from coal, graphite, and biomass.

170 citations

Journal ArticleDOI
TL;DR: A comprehensive review of recent developments in AIE materials and their mechanochromic, photodynamic therapeutic and theranostic, sensing and electroluminescence applications can be found in this paper.
Abstract: An unusual behavior of some organic luminophores in which intensity of emission is enhanced in aggregated condition is known as aggregation induced emission (AIE). The exposure of this concept to the scientific community significantly changes the perception towards conventionally used photophysical phenomena. Due to the high quantum yield and tunable emission properties, AIE luminogens (AIEgens) have become promising candidates for biosensors, opto-electronics and energy applications. The excellent stimuli responsiveness of AIE luminogens (AIEgens) provides them with a key edge for sensitive measurements such as intracellular temperature, pH, etc. In recent times the immense research interest in the AIE phenomenon stems from the inherent solid-state emission as well as its constructive effect on many other phenomena such as mechanochromism, thermally activated delayed fluorescence and circularly polarized luminescence. Many AIE fluorophores readily exhibit mechanochromism but still their interaction with external stimuli results in aggregation caused quenching (ACQ). However, the latest reports shed some light on designing and developing mechanochromophores with enhanced emission. With the inclusion of bright emission, photostability, great signal to noise ratio and non-invasiveness into one package of aggregation induced emission, a significant contribution for the enrichment of the field of photodynamic therapy and theranostics can be foreseen. Hence, the aim of this review is to provide a comprehensive study on recent developments in AIE materials and their mechanochromic, photodynamic therapeutic and theranostic, sensing and electroluminescence applications which offers new possibilities to utilize AIE materials. This review article is devoted to future research perspectives and challenges towards the development of AIE materials for modern technological and therapeutic applications.

78 citations

Journal ArticleDOI
TL;DR: In this article, a solution casting of polyvinyl chloride (PVC) with ZnO nanoparticles as a dopant was performed and the complex dielectric function, AC electrical conductivity and impedance spectra of these nanocomposites were investigated over the frequency range from 10 Hz to 35 MHz.
Abstract: In this work, polymer nanocomposites consisting of a poly(vinyl chloride) (PVC) and polyvinylidene fluoride (PVDF) polymer network with ZnO nanoparticles as a dopant were prepared by solution casting. An XRD study of the PVC/PVDF/ZnO polymer nanocomposites shows predominantly sharp and high intensity peaks. However, the intensity and sharpness of the XRD peaks decreases with further increment in loading of ZnO (wt%), which reveals a proper intercalation of ZnO nanoparticles within the PVC/PVDF polymer system. Fourier transform infrared spectroscopy has been used to verify the chemical compositional change as a function of ZnO nanoparticle loading. TGA analysis clearly describes the thermal degradation of the pure polymer and polymer nanocomposites. The complex dielectric function, AC electrical conductivity and impedance spectra of these nanocomposites were investigated over the frequency range from 10 Hz to 35 MHz. These spectra were studied with respect to the Wagner − Maxwell − Sillars phenomenon in the low frequency region. Nyquist plots of the PVC/PVDF/ZnO nanocomposites were established from impedance measurements. The temperature-dependent DC ionic conductivity obtained from the Nyquist plots follows Arrhenius behaviour. © 2016 Society of Chemical Industry

55 citations

Journal ArticleDOI
TL;DR: In this paper, polyvinyl alcohol (PVA) and Polyvinyl Pyrrolidone (PVP) based polymer electrolytes for different loading wt% of CdCl 2 were prepared by solution casting and structural complexation was confirmed and interlayer spacing was evaluated by using X- ray diffraction (XRD) study.
Abstract: Polyvinyl alcohol (PVA) and Polyvinyl Pyrrolidone (PVP) based polymer electrolytes for different loading wt% of CdCl 2 were prepared by solution casting. The structural complexation was confirmed and interlayer spacing (d) was evaluated by using X- ray diffraction (XRD) study. The chemical bonding between polymer and salt was identified by using Fourier transform infrared spectroscopy (FTIR) technique. The FTIR peak at 3402.43 cm -1 in addition of PVP in PVA/CdCl2 composite demonstrates the grafting between two polymers. The presence of ionic bright channels and variation in morphology for different loading wt% of CdCl2 was confirmed by scanning electron microscope (SEM) and was also verified by Atomic force microscopy (AFM) micrographs. The analysis of impedance spectroscopy represented by semicircular pattern is driven by conduction mechanism and correlated with electrical conductivity. The enhanced AC conductivity of polymer electrolyte is directly proportional to frequency (50Hz-1MHz). The maximum value of DC conductivity 1.65x10 -5 S/m evaluated from Arrhenius plots and attribute to high mobility of free charges at higher temperature. The evaluated results of structural, morphological and electrical properties of present composites make the present research good for electrochemical devices. Copyright © 2015 VBRI press.

37 citations

Journal ArticleDOI
30 Mar 2014-Ionics
TL;DR: In this article, a modified PVDF/PVA polymer system as a function of Nafion was detected by X-ray diffraction (XRD) and the major change in Fourier transform infrared (FTIR) spectroscopy confirms the chemical bond C=O stretching around 1,700 cm−1 due to Nafions.
Abstract: Polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA) composites were prepared by controlled loading of Nafion (5 to 15 wt%) by solution casting using water and dimethylformamide (DMF) as a solvent. The surface morphology of composite analyzed by atomic force microscopy (AFM) reveals the presence of Nafion ionomers. The increase in interlayer spacing of modified PVDF/PVA polymer system as a function of Nafion was detected by X-ray diffraction (XRD). The major change in Fourier transform infrared (FTIR) spectroscopy confirms the chemical bond C=O stretching around 1,700 cm−1 due to Nafion. Differential scanning calorimetry (DSC) demonstrates the thermal stability of polymer composites and the decrease in melting temperature (T m). The optimized AC conductivity (σ) of the prepared composite was evaluated by using an impedance analyzer as a function of temperature (40 to 150 °C) at constant 30-MHz frequency. The highest conductivity of 1.3 × 10−2 S m−1 was observed at 80 °C for 10 wt% of Nafion and correlated with structure, morphology and thermal properties of modified PVDF/PVA/Nafion composites. The experimental results may be useful for sensors, fuel cells and battery application domains.

31 citations


Cited by
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Book ChapterDOI
22 Apr 2012
TL;DR: In this article, the electromagnetic spectrum in Figure 1 illustrates the many different types of electromagnetic radiation, including gamma rays (γ-rays), X-rays, ultraviolet (UV) radiation, visible light, infrared (IR), microwaves, and radio waves.
Abstract: Spectroscopy is the study of matter interacting with electromagnetic radiation (e.g., light). The electromagnetic spectrum in Figure 1 illustrates the many different types of electromagnetic radiation, including gamma rays (γ-rays), X-rays, ultraviolet (UV) radiation, visible light, infrared (IR) radiation, microwaves, and radio waves. The frequency (ν) and wavelength (λ) ranges associated with each form of radiant energy are also indicated in Figure 1.

849 citations

01 Sep 2016
TL;DR: An original battery system that depends on the redox of I−/I3− couple in liquid cathode and the reversible enolization in polyimide anode, accompanied by Li+ (or Na+) diffusion between cathodes and anode through a Li+/Na+ exchange polymer membrane is presented.
Abstract: Environmentally-friendly aqueous Li (or Na)-ion battery with super-long life is built for large-scale energy storage. Current rechargeable batteries generally display limited cycle life and slow electrode kinetics and contain environmentally unfriendly components. Furthermore, their operation depends on the redox reactions of metal elements. We present an original battery system that depends on the redox of I−/I3− couple in liquid cathode and the reversible enolization in polyimide anode, accompanied by Li+ (or Na+) diffusion between cathode and anode through a Li+/Na+ exchange polymer membrane. There are no metal element–based redox reactions in this battery, and Li+ (or Na+) is only used for charge transfer. Moreover, the components (electrolyte/electrode) of this system are environment-friendly. Both electrodes are demonstrated to have very fast kinetics, which gives the battery a supercapacitor-like high power. It can even be cycled 50,000 times when operated within the electrochemical window of 0 to 1.6 V. Such a system might shed light on the design of high-safety and low-cost batteries for grid-scale energy storage.

225 citations

Journal ArticleDOI
15 Dec 2020-Fuel
TL;DR: In this article, a review article describing all possible directions related to such typical natural resources and application of their carbon derivatives/products for better electrochemical properties is presented, which will be very helpful for future research work in the field of carbon electrode materials derived from coal, graphite, and biomass.

170 citations

Journal ArticleDOI
TL;DR: In this article, reduced graphene oxide containing cobalt oxide (rGO@Co3O4/CoO) hybrid was synthesized via single-step microwave irradiation in which the uniform Co3O 4 /CoO nanoparticles were attached in thin layers of rGO nanosheets.
Abstract: In recent times, microwave synthetic strategies have been considered as one of the facile methods for the development of efficient supercapacitor electrodes. Reduced graphene oxide containing cobalt oxide (rGO@Co3O4/CoO) hybrids were synthesized via single-step microwave irradiation in which the uniform Co3O4/CoO nanoparticles were attached in thin layers of rGO nanosheets. During short time of single-step microwave irradiation process, three kind of phenomena occurs as (i) reduction and exfoliation of graphite oxide into rGO nanosheets, (ii) decomposition of cobalt(II) acetate into Co3O4/CoO nanoparticles and (iii) rGO nanosheets covers the Co3O4/CoO nanoparticles. The BET surface area and pore diameter range of rGO@Co3O4/CoO hybrids were 133.2 m2g−1 and 5–45 nm, respectively, which shows the mesoporous structure formation of hybrids. Electrochemical evaluations of rGO@Co3O4/CoO hybrids as electrode materials for supercapacitor shows specific capacitance of 276.1 F g−1 (scan rate of 5 mV s−1) and long-term cycling stability as 82.37% capacitance retention after 10,000 cycles (scan rate of 60 mV s−1) in 0.1 M KOH electrolyte solution. The Co3O4/CoO nanoparticles with conducting scaffolds rGO structure will pave an encouraging alternative for electrode materials and suggesting good potential for supercapacitors applications.

116 citations

Journal ArticleDOI
01 Jun 2022-Carbon
TL;DR: In this paper , a comprehensive overview of the state-of-the-art on the fabrication of supercapacitor electrodes is presented, including novel carbon nanomaterials having different dimensions, such as 0D-carbon quantum dots, 1D-Carbon nanostructures (carbon nanotubes, carbon nanofibers, carbon nano yarns and their composites) as well as 2D-carbon materials (graphene, doped-graphenes, graphene derivatives and their compositions).

108 citations