Madhushree M. Ravikumar; Vijeth R. Shetty; Suresh G. Shivappa
Abstract
Two organic compounds namely Acridine (ACD) and 9-aminoacridine (ACD-NH2) have been investigated as electrode materials for an aqueous rechargeable lithium-ion battery (ARLIB) applications. The electrochemical investigations reveal that the active species act as anodes in ARLIB systems. In this regard, ...
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Two organic compounds namely Acridine (ACD) and 9-aminoacridine (ACD-NH2) have been investigated as electrode materials for an aqueous rechargeable lithium-ion battery (ARLIB) applications. The electrochemical investigations reveal that the active species act as anodes in ARLIB systems. In this regard, nitrogen group act as redox center and undergo electrochemical reaction with Li-ions during charge and discharge process. The synthesis of 9-amonoacridine is done by standard method called chichibabin reaction. Amination of ACD enhances the electrochemical behaviour of the molecule. To improve the electrochemical performances of ACD & ACD-NH2, graphene is used as an additive for ARLIB system. The decorated molecules such as decorated Acridine (dACD) and decorated 9-aminoacridine (dACD-NH2) showed improved electrochemical performance as compared with ACD & ACD-NH2. The decoration is of great importance concerning capacity, reversibility and stability of cycling behavior during charge and discharge processes. Charge/discharge tests show that ACD, ACD-NH2, dACD, and dACD-NH2 have achieved initial discharge capacities of 119, 122, 149 and 220 mAh g -1 respectively at a current density of 0.2 mA. The good cyclic performance and agreeable discharge capacity of the cell signifies the application of dACD-NH2 as anode material for ARLIB system. Copyright © VBRI Press.
R. Anil Kumar; R. Vijeth Shetty; G. S.Suresh; K. M. Mahadevan
Abstract
Aqueous or non-aqueous rechargeable lithium ion batteries with organic electrodes as a current carrier can perform effectively sensible and affordable energy storage devices due to large accessibility of organic materials. Here we report a high-performance lithium-based energy storage device using 3,3'-(naphthalen-1-ylmethanediyl)bis(1H-indole) ...
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Aqueous or non-aqueous rechargeable lithium ion batteries with organic electrodes as a current carrier can perform effectively sensible and affordable energy storage devices due to large accessibility of organic materials. Here we report a high-performance lithium-based energy storage device using 3,3'-(naphthalen-1-ylmethanediyl)bis(1H-indole) (NBI) as anode material for Aqueous Rechargeable Lithium-ion Battery. The active material is synthesized by condensation between indole and naphthaldehyde under stirring in glacial acetic acid, followed by lithiation by ball milling method. The obtained samples have been characterized by the combination of elemental analysis, NMR, FT-IR and powder XRD. The electrochemical measurements show that the cell Li-NBI | Sat. Li2SO4 | LiFePO4 has been delivered an initial discharge capacity of 113 mAh g −1 at lower current density. At the high current density 75 mAh g −1 discharge capacity can be achieved, which represents its high rate capability. Consequently, the as-prepared Li-NBI could be a potential active species as low-cost anode materials for lithium batteries. The kinetics of electrode reactions under saturated Li2SO4 have been studied by Potentiostatic Electrochemical Impedance Spectroscopic method, show the semi-infinite behaviour at peak potentials. These considerations may be rendering the effective rate performance during charge/discharge process.
Upama Baruah;Devasish Chowdhury
Abstract
The present work demonstrates the electrochemical detection of the endocrine disruptor Bisphenol A in solution by three different types of functionalized graphene samples viz. graphene oxide (GO), ester functionalized graphene oxide (GO-ES) and amine functionalized graphene oxide (GO-en) modified glassy ...
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The present work demonstrates the electrochemical detection of the endocrine disruptor Bisphenol A in solution by three different types of functionalized graphene samples viz. graphene oxide (GO), ester functionalized graphene oxide (GO-ES) and amine functionalized graphene oxide (GO-en) modified glassy carbon electrode (GCE) using a very simple drop casting method without the use of any toxic organic compounds or polymeric binders via cyclic voltammetry. The system developed showed detection of BPA via formation of a π-stacked layered functionalized graphene oxide-BPA (π-s-GO-BPA) nanocomposite accompanied by a reduction in the oxidation peak current value associated with a significant shift in the peak potential value. The electrochemical sensing materials developed showed good sensitivity compared to already reported systems and furthermore high selectivity in presence of other structurally similar kinds of molecules in solution without the use of any toxic organic chemicals thereby demonstrating the practical applicability of the material and the technique developed. The practical viability of the material developed is also demonstrated via testing with a real low quality plastic sample that contains Bisphenol A. A plausible mechanism to justify the detection process is also being discussed.
M. Sivaprasad; N. Y. Sreedhar; M. R. Jayapal; Li Yang; Hongwei Ni
Abstract
Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) ...
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Herein we reported graphene (Gr) was firstly fabricated on glassy carbon electrode (GCE) by drop casting method, subsequently polyaniline (PAN) and Palladium (Pd) nanocomposite were fabricated by two-step electrochemical depositing process on graphene dispersed glassy carbon electrode (Gr/GCE) and used as an electrochemical sensor for determination of Tetrachlorvinphos (TCP < /span>) pesticide in vegetables. Here most of the work has been focused on the preparation and characterization of modified electrode with cyclic voltammetry (CV) and scanning electron microscopy (SEM). The modified composite electrode unveiled significantly good voltammetric response on TCP. Square wave voltammetry (SWV) was used for determination of TCP at optimized conditions such as square wave frequency, step potential, pH of buffer, applied sample volume, accumulation potential and accumulation time. The well-defined reduction (C=C) peaks were acquired over the potential maximum around at -1.3V in acidic medium in Briton-Robinson (B-R) buffer solution at low current values. The low current peaks were obtained over the concentration of TCP at 1.5×10 -6 M with lower detection limit and limit of quantifications are 5.62×10 -10 M and 2.65×10 -8 respectively. The composite modified electrode showed good stability and reproducibility. The proposed method was successfully applied for the present investigation with a great assure as an economical and simple sensor with furthermore a shorter analysis time and further the sensor also used for heavy metal detection in real samples.
Umesh Rizal; Bhabani S. Swain; Bibhu P. Swain
Abstract
We have synthesized carbon nanoparticles (CNPs) via the sol-gel method using dextrose as carbon source with different concentration of ethanol. The effects of ethanol concentration (0.2 to 2.0 M) on the chemical network, electrochemical and photoluminescence properties of CNPs were examined using Fourier ...
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We have synthesized carbon nanoparticles (CNPs) via the sol-gel method using dextrose as carbon source with different concentration of ethanol. The effects of ethanol concentration (0.2 to 2.0 M) on the chemical network, electrochemical and photoluminescence properties of CNPs were examined using Fourier transform infra-red (FTIR) spectroscopy, Raman spectroscopy, cyclic voltammetry and photoluminescence (PL) spectroscopy. Field emission scanning electron microscopy (FESEM) image of CNPs shows CNPs of 40-80 nm were synthesized by sol-gel method. Chemical network study reveals the presence of various bonds such as C-H, C-H2, C-H3 and aromatic carbon present on the surface of the CNPs. Raman spectra shows that increasing of ethanol concentration decreases the crystalline size of CNPs. Cyclic voltammetry analysis shows prominent oxidation peaks at 0.1-0.2 V whereas the reduction peak observed at 0.2 V. The observed room temperature PL peak at 2.9 eV confirms a blue emission from CNPs.
Nitin R. Dighore; Suresh T. Gaikwad; Anjali S. Rajbhoj
Abstract
A voltammetric sensor was developed for detection of glucose by using cyclic voltammetry (CV). The sensing platform was Polypyrrole-Pt nanocomposites on Platinum electrode (PPy-Pt-PtE). PPy-Pt was synthesized by chemical method, using FeCl3 oxidant. XRD, SEM and TEM results showed that PPy doped with ...
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A voltammetric sensor was developed for detection of glucose by using cyclic voltammetry (CV). The sensing platform was Polypyrrole-Pt nanocomposites on Platinum electrode (PPy-Pt-PtE). PPy-Pt was synthesized by chemical method, using FeCl3 oxidant. XRD, SEM and TEM results showed that PPy doped with Pt were highly porous, nanocrystalline composites. The PPy-Pt-PtE modified electrode observed reversible behavior with ferricyanide system which had about 2.05 times more surface area and exhibited higher currents for glucose oxidation compared to bare PtE. Glucose was sensed in the range of 100mM to 1000 mM from the linear regression plotted R 2 = 0.990 and R 2 = 0.994 the sensitivity was found to be 0.047 mA/mM~cm 2 and 0.0445 mA/mM~cm 2 . These results indicate that PPy-Pt-PtE exhibited good platform and could be used for voltammetric determination of glucose.
Bikash Mandal; I. Basumallick; Susanta Ghosh
Abstract
We report a novel cathode of the molecular formula, Li2MZrO4 (M = Fe, Mn), based on an inexpensive, earth-abundant, and eco-friendly materials, which have theoretical capacities within 119 – 238 mAh.g -1 depending on the number of lithium ions extracted from material, suitable for high power rechargeable ...
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We report a novel cathode of the molecular formula, Li2MZrO4 (M = Fe, Mn), based on an inexpensive, earth-abundant, and eco-friendly materials, which have theoretical capacities within 119 – 238 mAh.g -1 depending on the number of lithium ions extracted from material, suitable for high power rechargeable lithium-ion battery. X-ray diffraction (XRD) revealed tetragonal crystal structure of the synthesized material. SEM images illustrate the formation of porous material with large surface area. The cyclic voltammograms of Li2MZrO4 (M=Fe, Mn) showed only one pair of redox peak corresponding to the anodic and cathodic reactions within a potential window of 2.2 – 4.5 volts vs. Li/Li + . The first discharge capacities were 89 mAhg -1 for Li2FeZrO4, whereas in case of Li2MnZrO4 it was 94 mAhg -1 at 0.1 C rates, which are equivalent to removal of one lithium ion from the compounds.
Ashok Kumar Sharma; Preetam Bhardwaj; Sundeep Kumar Dhawan; Yashpal Sharma
Abstract
A novel study on conducting polymers based composites involving hybrid carbon nanostructure assemblage of graphene, amine functionalized multiwalled carbon nanotubes and poly(aniline-co-pyrrole) has been done. The composites were synthesized by oxidative polymerization of 1:1 mixture of aniline and pyrrole ...
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A novel study on conducting polymers based composites involving hybrid carbon nanostructure assemblage of graphene, amine functionalized multiwalled carbon nanotubes and poly(aniline-co-pyrrole) has been done. The composites were synthesized by oxidative polymerization of 1:1 mixture of aniline and pyrrole monomer with ammonium per sulphate and ferric chloride oxidants. UV-vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy were used to identify the chemical structure of the obtained composites. Thermal studies indicate that the composites are stable in comparison to poly (aniline-co-pyrrole) alone showing that the hybrid carbon assemblage contributes towards thermal stability in the composites. Crystalline properties of the composites were investigated by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to characterize the surface morphology of the composites. The specific capacitance of the composites was characterized by cyclic voltammogram (CV). The capacitive studies reveal that the composite has synergistic effect and highest specific capacitance of 337.35F/g at scan rate of 10mV/sec and 193.06F/g at scan rate of 50 mV/sec was obtained for the composite having thinnest layer of co-polymer over hybrid carbon assemblage i.e., 02-PANI-co-PPY-C.
Ritu P. Mahore; Devendra K. Burghate; Subhash B. Kondawar
Abstract
Supercapacitors are recognized as one of the most promising energy storage devices for a wide range of civilian and military applications in electric vehicles, uninterruptible power supplies. Conducting polymer nanocomposites are new functional materials suitable for supercapacitors due to synergistic ...
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Supercapacitors are recognized as one of the most promising energy storage devices for a wide range of civilian and military applications in electric vehicles, uninterruptible power supplies. Conducting polymer nanocomposites are new functional materials suitable for supercapacitors due to synergistic effect of individual components. In present work, polypyrrole/CNT nanocomposites have been prepared by an in-situ chemical polymerization method and studied for supercapacitor. CNTs were well functionalized using 3:1 ratio of H2SO4 and HNO3 before polymerizing the pyrrole. Analytical techniques such as SEM, UV-VIS and FTIR were used to characterize the synthesized materials. The SEM images reveal that the materials have rough and granular morphology. The composites showed good interaction based on the shift to longer wavelengths in the electronic transition, indicating the interaction between PPy and functionalized CNTs as observed in their UV-VIS and FTIR spectra. The electrochemical performance was evaluated by using cyclic voltammetry (CV) in 1M Na2SO4 electrolyte and specific capacitance was obtained at 0.5 V/s for pure polypyrrole and PPy/CNT nanocomposites. Nanocomposite showed the enhanced electrochemical performance as compared to that of pure polypyrrole. The specific capacitance obtained at the scan rate 0.5V/s was found to be 0.825 F/cm -2 for pure polypyrrole and 1.0619 F/cm -2 for PPy/CNT nanocomposite material respectively, indicates that PPy/CNT nanocomposite is suitable material as electrode for supercapacitor as compoared to pure polypyrrole.
Nuo Zhang; Caixia Xu; Qin Wei; Bin Du; Ru Li; Tianguo Zhang; Dan Wu; Yuxue Dai
Abstract
Nano-scale hydroxyapatite (HAp) was prepared by combining co-precipitation with microemulsion method, which exhibited strong adsorption for DNA due to its excellent biocompatibility and particular adsorbability. DNA and HAp could be modified onto glassy carbon electrode (GCE) by the simple and convenient ...
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Nano-scale hydroxyapatite (HAp) was prepared by combining co-precipitation with microemulsion method, which exhibited strong adsorption for DNA due to its excellent biocompatibility and particular adsorbability. DNA and HAp could be modified onto glassy carbon electrode (GCE) by the simple and convenient “tip-coating” method. Cyclic voltammetry was used to investigate the interaction of DNA immobilized on the HAp film with vitamin B12 (VB12). The existence of DNA led to the decrease of reduction current of VB12. Both the electron transfer coefficient (α) and the standard rate constant (ks) were different obtained on GCE and dsDNA/HAp/GCE, which indicated the formation of an electrochemical inactive super molecular complex DNA-nVB 12 . The equilibrium constant of this complex was calculated to be 5.35 × 10 5 mol·L -1 and the binding number between DNA and VB12 of the complex were determined to be one.
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