Showing papers by "Bishop Heber College published in 2018"

Photocatalytic Degradation of Rhodamine B Using Zinc Oxide Activated Charcoal Polyaniline Nanocomposite and Its Survival Assessment Using Aquatic Animal Model

Abstract: Zinc oxide activated charcoal polyaniline (ZACP) nanocomposite were prepared using a simple precipitation method. The as-synthesized photocatalyst was characterized by XRD, SEM, HRTEM, EDX, UV–vis, PL, XPS, and BET techniques. Results confirmed the successful incorporation of activated charcoal polyaniline (AC/PANI) on ZnO nanoparticles. The photocatalytic activity of the as-synthesized ZACP was assessed by the photodegradation of Rhodamine B (RhB) using visible light irradiation. The improved photocatalytic activity of the sample was ascribed to the synergetic effect between AC/PANI and ZnO which effectively separates the electron hole pair on the interface of PANI and ZnO. Survival assessment was carried out using Artemia salina (AS) to determine the detoxification potential of the degraded products. In survival assessment, treated dye solution exhibited less toxic effect when compared to the untreated dye solution. A mechanism was also proposed for the degradation of RhB dye using ZACP under visible li...

Polyaniline based charcoal/Ni nanocomposite material for high performance supercapacitors

Abstract: A facile wet chemical method was developed to synthesize a PANI/charcoal/Ni nanocomposite (PANI/AC/Ni), which was found to show significant electrochemical performance as a supercapacitor. The as-prepared sample was characterized by various spectral and analytical techniques. The newly fabricated PANI/AC/Ni nanocomposite electrode exhibited excellent specific capacitance with a maximum value of 1661 F g−1 at a discharge current density of 1 A g−1. Furthermore, the composite electrode showed a specific capacitance retention of 93% after 2000 charge–discharge cycles. Thus the PANI/AC/Ni nanocomposite was proved to be a promising electrode material for high-performance supercapacitors.

Dynamics of lumps and dark–dark solitons in the multi-component long-wave–short-wave resonance interaction system

Abstract: General semi-rational solutions of an integrable multi-component (2+1)-dimensional long-wave-short-wave resonance interaction system comprising multiple short waves and a single long wave are obtained by employing the bilinear method. These solutions describe the interactions between various types of solutions, including line rogue waves, lumps, breathers and dark solitons. We only focus on the dynamical behaviours of the interactions between lumps and dark solitons in this paper. Our detailed study reveals two different types of excitation phenomena: fusion and fission. It is shown that the fundamental (simplest) semi-rational solutions can exhibit fission of a dark soliton into a lump and a dark soliton or fusion of one lump and one dark soliton into a dark soliton. The non-fundamental semi-rational solutions are further classified into three subclasses: higher-order, multi- and mixed-type semi-rational solutions. The higher-order semi-rational solutions show the process of annihilation (production) of two or more lumps into (from) one dark soliton. The multi-semi-rational solutions describe N(N≥2) lumps annihilating into or producing from N-dark solitons. The mixed-type semi-rational solutions are a hybrid of higher-order semi-rational solutions and multi-semi-rational solutions. For the mixed-type semi-rational solutions, we demonstrate an interesting dynamical behaviour that is characterized by partial suppression or creation of lumps from the dark solitons.

Isolation of Cp*CoIII–Alkenyl Intermediate in Efficient Cobalt-Catalyzed C−H Alkenylation with Alkynes

Abstract: A general and efficient procedure for C-H alkenylation of arenes with a broad substrate scope catalyzed by Cp*CoIII was demonstrated with alkynes. A highly selective mono-alkenylation and sequential bis-C-H bond functionalization was displayed to exemplify the versatility of the cobalt catalyst. Isolation of cationic Cp*CoIII -alkenyl intermediate was achieved under identical catalytic conditions to further establish the proposed pathway.

Influence of Hydrothermally Synthesized Cubic-Structured BaTiO3 Ceramic Fillers on Ionic Conductivity, Mechanical Integrity, and Thermal Behavior of P(VDF–HFP)/PVAc-Based Composite Solid Polymer Electrolytes for Lithium-Ion Batteries

Abstract: Solid polymer electrolytes (SPEs) with high ionic conductivity and wide electrochemical window are highly desirable for all-solid-state rechargeable lithium batteries. Herein, we report the use of ...

Determination of 8-hydroxy-2′-deoxyguanosine oxidative stress biomarker using dysprosium oxide nanoparticles@reduced graphene oxide

Abstract: 8-Hydroxy-2′-deoxyguanosine (8-OHdG) is a risk factor; it plays a crucial role in inducing oxidative stress involved in the physiological processes and it is a biomarker in the response to human disease and injury. Therefore, the development of a robust, low-cost, and portable analytical tool for quantification of 8-hydroxy-2′-deoxyguanosine in human blood and urine samples is required. It is essential to diagnose oxidative stress-related diseases in human body. For this purpose, herein, we report an electrochemical sensor based on Dy2O3 nanoparticle-decorated reduced graphene oxide nanocomposite (Dy2O3 NPs@RGO). A microwave-assisted synthetic route was adopted to prepare Dy2O3 NPs@RGO. Subsequently, its morphological, elemental, and crystal structure properties were analyzed. Electrochemical and interfacial properties were examined to ensure the material's suitability in electrocatalytic sensing. Dy2O3 NPs@RGO-affixed conventional screen-printed electrode (SPCE) was found to exhibit tremendous electrocatalytic capability toward 8-OHdG oxidation. A sensitive and reproducible sensor for the amperometric detection of 8-OHdG was fabricated, which could detect concentrations as low as 1.02 nM. The method worked well even in real samples (human urine and blood serum), and the results were validated by the HPLC method, indicating the reliability of the proposed method in clinical analysis.

Isatin based macrocyclic Schiff base ligands as novel candidates for antimicrobial and antioxidant drug design: In vitro DNA binding and biological studies.

Abstract: In the present work, five macrocyclic compounds, C18H12N2O4 (1), C38H24N8O6 (1a), C38H24N8O4S2 (1b), C40H32N8O4 (2a) and C48H32N8O4 (2b) have been synthesized and thoroughly characterized by elemental analysis, FT-IR, 1D & 2D NMR and electron spray ionization mass spectral analysis. The DNA binding ability of these compounds were investigated in vitro by UV-Visible, fluorescence, circular dichroism (CD) spectroscopy and viscosity measurements. The results indicate that these compounds possess strong DNA binding affinity via intercalation, while the order of binding strength followed the trend 2b (1.52 ± 0.06 × 105 M-1) > 2a (1.12 ± 0.11 × 105 M-1) > 1b (1.05 ± 0.04 × 105 M-1) > 1a (0.97 ± 0.14 × 104 M-1) > 1 (0.75 ± 0.21 × 104 M-1). The radical scavenging potencies of the compounds were explored by employing DPPH, OH and NO assays, in which 1a exhibited highest inhibitory effect on the radicals (IC50 = 23.59 μM (DPPH), 26.14 μM (OH), 28.41 μM (NO)). The in vitro antibacterial studies showed that these compounds have the potential to arrest the growth of bacteria, among which, 1a was found to be vulnerable against the bacterial stains. In addition, in silico molecular docking stimulations were also performed to position these compounds into the active sites of bacterial membrane proteins. The results of in vitro and in silico investigations reveal that the compounds apprehend the bacterial growth significantly. The data obtained from this piece of work would be helpful to design antibacterial drugs incorporating isatin based macrocyclic frameworks.

Cost effective synthesis of a copper-1H-imidazole@activated carbon metal organic framework as an electrode material for supercapacitor applications

Abstract: The present work describes the synthesis of a copper-1H-imidazole metal organic framework (Cu-I MOF) and copper-1H-imidazole@activated carbon metal organic framework (Cu-IC MOF) via a simple chemical route under ultrasonication. The formation of the as-synthesized MOFs was confirmed by various spectral and analytical techniques. The electrochemical properties of the MOFs are examined for supercapacitor applications as an electrode material using Cyclic Voltammetry (CV), Galvanostatic Charge–Discharge (GCD) and Electrochemical Impedance Spectroscopic (EIS) techniques. Comparison of the results obtained from the CV and GCD studies reveals that the Cu-IC MOF has a specific capacitance greater than that of Cu-I, i.e. 753 F g−1 at a scan rate of 5 mV s−1 by CV and 733 F g−1 at a current density of 1 A g−1 by GCD for the Cu-IC MOF while 596 F g−1 by CV and 252 F g−1 by GCD for the Cu-I MOF. The Cu-IC MOF retained about 85% of its initial capacitance even after 2000 GCD cycles at 1 A g−1 current density. This observation proves that the Cu-IC MOF may be a potential electrode material for supercapacitor applications.

Effect of Ni2+ doping on chemocatalytic and supercapacitor performance of biosynthesized nanostructured CuO

Abstract: The synthesis of metal oxide nanostructured materials derived from plant extract embraces the futuristic design of an eco friendly system by reducing the hazardous toxic chemicals. In the present work, copper oxide nanoparticles (CuO NPs) and Ni2+ doped (0.003, 0.006 and 0.009 M) CuO NPs were prepared by green method using Azadirachta indica (A. indica) leaf extract. The XRD pattern reveals that the synthesized CuO NPs exhibits monoclinic structure. Nanoflower like morphology is observed in FESEM and TEM analysis. The oxidation states of Cu (2p), Ni (2p) and O (1s) have been identified in XPS spectra. The weight loss and thermal effects were investigated in TG–DSC analysis. The green synthesized materials effectively degrade the hazardous water pollutants like methylene blue, methyl orange and eosin yellow. The pseudocapacitive properties of CuO and Ni doped CuO NPs have been investigated through cyclic voltammetry and galvanostatic charge–discharge (GCD) studies. The Ni doped (0.009 M) CuO NPs exhibited high specific capacitance of 511 F/g at a current density of 1 A/g, and good reversibility with cycling efficiency of 88% after 3000 GCD cycles for S4 electrode, suggesting its use as promising electrode material in supercapacitors.

Optimization of CdO nanoparticles by Zr 4+ doping for better photocatalytic activity

Abstract: Chemically controlled co-precipitation method has been adopted for the fabrication of pure and different wt% Zr doped CdO photocatalysts. Conventionally, the crystallite size and crystalline phase of CdO are in the midst of the parameters involved in the control of the photocatalytic activity. Aiming utterly at the size effect that modifies other attributes which are important to assess the photocatalytic activity of nanometric CdO, it was explored to synthesize CdO nanoparticles with controlled size, highly comparable morphology and analogous phase. The crystal structure and the crystallite size were estimated from the X-ray diffraction patterns and were confirmed through transmission electron microscope. The degree of crystallinity varied on Zr doping and the calculated crystallite sizes were in the range of 16–81 nm. The dopant ion Zr4+ have been detected through X-ray photoelectron spectroscopy (XPS) analysis signifying the dopant to substitute for cadmium (Cd2+) in the lattice of CdO. Particle size dependent optical band gaps calculated in the range 2.02–2.57 eV informed the viability of the materials to initiate photocatalytic reaction in the visible light region. Lesser recombination rate of the generated electrons and holes under light irradiation produced low intense photoluminescence peaks that displayed the appropriateness as photocatalysts. Zr4+ doping resulted in the enhancement of photocatalytic activity, evaluated by monitoring the degradation of methylene blue solution. 0.5 wt% Zr doped CdO nanoarticles calcined at 400 °C exhibited the highest photocatalytic activity with better percentage of color abatement (80.95%). The pseudo-first-order reaction rate became faster on Zr doping such that the rate constant is ~ 0.4–0.5 h−1 for Zr doped CdO while that for pure CdO is ~ 0.3 h−1.

Efficient direct plant regeneration from immature leaf roll explants of sugarcane ( Saccharum officinarum L.) using polyamines and assessment of genetic fidelity by SCoT markers

Abstract: A rapid and efficient method for in vitro direct plant regeneration from immature leaf roll explants of Saccharum officinarum L. (sugarcane) cv. Co 86032 was developed by the application of exogenous polyamines (PA). The effect of explant source from apical meristems and pre-culture of explants in the dark on shoot regeneration was studied. Adventitious shoot regeneration occurred on the proximal regions of immature leaf roll explants when pre-incubated in the dark for 2 wk and the regeneration response was decreased from the middle to distal end. A higher number of direct shoots (130 primary shoots explant−1) and multiple shoots (657 secondary shoots explant−1), were obtained with a combination of spermidine (103.27 μM), spermine (49.42 μM), and putrescine (31.04 μM) along with plant growth regulators. Shoot induction was increased up to twofold and multiplication was increased up to threefold in the medium supplemented with PA. Profuse rooting was observed in putrescine (93.12 μM), spermidine (68.84 μM), and spermine (24.71 μM), with mean number of 57 roots. A twofold increase in the number of roots was observed in medium supplemented with PA with respect to control cultures, which facilitated the successful transplantation and acclimatization process of in vitro propagated sugarcane plants. Histology and scanning electron microscopy analyses supported adventitious direct shoot regeneration from immature leaf roll explants. The genetic stability of in vitro regenerated plants was confirmed using start codon targeted polymorphism marker system.

N‐substituted hydroxynaphthalene imino‐oxindole derivatives as new class of PI3‐kinase inhibitor and breast cancer drug: Molecular validation and structure–activity relationship studies

Abstract: N-substituted hydroxynapthalene imino-oxindole derivatives (5a-g) were emerged as the inhibitors of the phosphoinositide 3-kinase (PI3K) which is a crucial regulator of apoptosis or programmed cell death. Electron donor/acceptor substituted indole-imine (5a-g) were achieved and the structures were elucidated by FTIR, 1H NMR, 13C NMR, and HRMS. PI3Ks inhibition potency was assessed by competitive ELISA. Subsequently, an anticancer activity against breast cancer (MCF-7) cell lines was evaluated. In both activities, compounds 5c, 5d, 5f and were showed most potent activities. Percentage inhibition for anticancer activity was 78.22±1.02 (5c), 78.98±1.08 (5f) and the IC50 was 2.02±0.92 μM (5c), 1.98±0.18 μM (5f). Compounds 5a and 5g were found inactive for both activities and rest all were showed a moderate activity. In order to get more insight into the binding mode and inhibitor binding affinity, 5a-g were docked into the active site of PI3Ks p110α (PDB ID: 2ENQ). Results suggested that the hydrophobic interactions in the binding pockets of PI3Ks conquered affinity of the most favourable binding ligands (5c and 5f: inhibitory constant (ki) = 102.4 nM and 128.23 nM). The SAR studies demonstrate the efficiency of 5a-g as the PI3Ks precise inhibitors with the impending to treat various cancers. This article is protected by copyright. All rights reserved.

Harnessing energy-sharing collisions of Manakov solitons to implement universal NOR and OR logic gates

Abstract: The energy-sharing collision of bright optical solitons in the Manakov system, governing pulse propagation in high birefringent fiber, is employed theoretically to realize optical logic gates. In particular, we successfully construct (theoretically) the universal NOR gate and the OR gate from the energy-sharing collisions of just four bright solitons which can be well described by the exact bright four-soliton solution of the Manakov system. This construction procedure has important merits such as realizing the two input gates with a minimal number of soliton collisions and possibilities of multistate logic. The recent experiments on Manakov solitons suggest the possibility of implementation of this theoretical construction of such gates and ultimately an all-optical computer.

Low-cost and eco-friendly nebulizer spray coated CuInAlS 2 counter electrode for dye-sensitized solar cells

Abstract: CuInAlS2 thin films for different substrate temperatures were deposited by a novel nebulizer spray technique. The polycrystalline CIAS thin film exhibited tetragonal structure with the preferential orientation of (1 1 2) plane. Nanoflakes were observed from the surface morphology of CIAS film. The peak position of core level spectra confirms the presence of CuInAlS2 from XPS analysis. The absorbance spectra and optical band gap were observed from the optical property. The activation energy, carrier concentration, hole mobility and resistivity were determined by linear four probe and Hall effect measurements. The CIAS film was used as a counter electrode (CE) in dye-sensitized solar cells (DSSCs) and is characterized by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel measurements. DSSC fabricated with the CIAS CE achieved the photo conversion efficiency of about 2.55%.

Pronounced luminescence efficiency and thermal stability of small imidazole architect 2-(1, 4, 5-triphenyl-1H-imidazol-2-yl)phenol for efficient non-doped blue OLEDs

Abstract: A remarkable attention have been devoted to fabricate blue OLEDs, since it plays a vital role in the field of organic electronics particularly in full colour flat panel displays. Though, notable research outputs were emerged, it is still being a challenging task by the researchers to fulfil its essential criteria such as highly efficient, colour stable and long life-span materials. With the view to address the issues, herein we report an easy synthetic strategy under catalyst free condition for a single imidazole moiety, 2-(1, 4, 5-triphenyl-1H-imidazol-2-yl)phenol, (TSPI-1) with excellent emissive behavior and high thermal stability. OLED device utilizing TSPI-1 as an active layer with the configuration of ITO/PEDOT: PSS (40 nm) /TSPI-1 (60 nm)/ TPBi (30 nm) / LiF (1 nm)/Al (100 nm) displayed blue emission with the maximum brightness of 1.60 Cd/m2, CIE coordinates (0.17, 0.18) and the turn on voltage of 3.77 V. The synthesized imidazole derivative, TSPI-1 was well characterized by FT-IR, UV–vis, photoluminescence (PL), 1H & 13C NMR, TGA-DTA, mass spectrometry and cyclic voltammetric (CV) studies. The results revealed the existence of localized electron density through non-planar geometry, specifically in solid state, good decay time, better morphological stability, (Tg = 111.93 °C) and high decomposition temperature (Td = 344 °C), therefore rendering it as a highly desirable material to fabricate OLED device under vacuum evaporation.

Solvent volume-driven CuInAlS2 nanoflake counter electrode for effective electrocatalytic tri-iodide reduction in dye-sensitized solar cells

Abstract: The influence of solvent volume on the properties of CuInAlS2 (CIAS) thin films deposited using simple and cost-effective nebulizer spray technique is studied. The polycrystalline CIAS thin films with tetragonal structure have been observed from the XRD results. SEM images show nanoflake-like structure on the film surface. The elemental presence and its chemical composition were examined by XPS and EDS. The deposited CIAS film for different solvent volume exhibited p-type semiconductor. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization measurements demonstrated that CIAS counter electrodes are capable of tri-iodide reduction process. The performances of photocurrent density-voltage for the CIAS CE exhibited the maximum efficiency of 2.55% with the short-circuit current density of 7.22 mA cm−2.