An Ag-TiO photocatalyst with 3.5 atom % silver content, synthesized by a single step sol-gel method, possessed silver nanoparticles (AgNPs; 1-5 nm) on the TiO surface, but owing to the nonplasmonic nature of AgNPs and the wide band gap of TiO, this material exhibited poor activity in a photocatalytic degradation reaction. However, this least active Ag-TiO catalyst showed a sudden increase in activity during a photocatalytic amine self-coupling reaction showing the highest activity, which was interpreted as amine (reactant) adsorption-driven activity enhancement.
View Article and Find Full Text PDFOre minerals in dolomites and Graphite Mica Schist (GMS) were studied by synchrotron radiation micro-computed tomography (SR-μCT) and optical microscopy. High resolution μCT images of ore minerals were obtained at Imaging Beamline (BL-4), Indus-2 synchrotron radiation source for the comprehensive volume characterization of minerals. Optical microscopy was used for mineral identification, mineral/rock characterization and quantification of ore mineral assemblages was also confirmed by XRD.
View Article and Find Full Text PDFJ Synchrotron Radiat
January 2017
Experiments were conducted to study the effects of static magnetic fields (SMFs) on the venation network of soybean leaves using the synchrotron-based X-ray micro-imaging technique. The seeds of soybean (Glycine max, variety JS-335) were pretreated with different SMFs from 50 to 300 mT in steps of 50 mT for 1 h. The phase-contrast images obtained showed that, as the strength of the SMF increased, the area, width of the midrib, area of the midrib and minor vein of the middle leaflets of third trifoliate leaves also increased up to the SMF strength of 200 mT (1 h) and decreased thereafter.
View Article and Find Full Text PDFX-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) of Nd-doped phosphate glasses have been studied before and after gamma irradiation. The intensity and the location of the white line peak of the L-edge XANES of Nd are found to be dependent on the ratio O/Nd in the glass matrix. Gamma irradiation changes the elemental concentration of atoms in the glass matrix, which affects the peak intensity of the white line due to changes in the covalence of the chemical bonds with Nd atoms in the glass (structural changes).
View Article and Find Full Text PDFThe hydraulic efficiency of a leaf depends on its vascular structure as this is responsible for transport activities. To investigate the effect of exclusion of UVAB and UVB radiation from the solar spectrum on the micro-structure of leaves of soybean (Glycine max, variety JS-335), a field experiment was conducted using synchrotron-based phase contrast imaging (PCI). Plants were grown in specially designed UV exclusion chambers, and wrapped with filters that excluded UVB (280-315 nm) or UVAB (280-400 nm), or transmitted all the ambient solar UV (280-400 nm) radiation (filter control).
View Article and Find Full Text PDFBackground: Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples.
Objective: The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph).
Hydrophobic anticancer drug, raloxifene hydrochloride (RH) is intercalated into a series of magnesium aluminum layered double hydroxides (LDHs) with various charge density anions through ion exchange technique for controlled drug delivery. The particle nature of the LDH in presence of drug is determined through electron microscopy and surface morphology. The release of drug from the RH intercalated LDHs was made very fast or sustained by altering the exchangeable anions followed by the modified Freundlich and parabolic diffusion models.
View Article and Find Full Text PDFAbstract: The paper reports the fabrication of Zn-doped TiO nanotubes (Zn-TONT)/ZnO nanoflakes heterostructure for the first time, which shows improved performance as a photoanode in dye-sensitized solar cell (DSSC). The layered structure of this novel nanoporous structure has been analyzed unambiguously by Rutherford backscattering spectroscopy, scanning electron microscopy, and X-ray diffractometer. The cell using the heterostructure as photoanode manifests an enhancement of about an order in the magnitude of the short circuit current and a seven-fold increase in efficiency, over pure TiO photoanodes.
View Article and Find Full Text PDFSingle crystal like TiO(2) nanotubes with preferential orientation along the [001] direction, parallel to the growth direction of nanotubes, that offer ease of charge transport much higher than reported so far, are fabricated using a cost effective two step technique. The success of this method to grow the nanotubes with the anomalous intense [001] preferential orientation is attributed to the zinc assisted minimization of the (001) surface energy. The single crystal like TiO(2) nanotubes show superior performance as supercapacitor electrodes compared to the normal polycrystalline titanium dioxide nanotubes.
View Article and Find Full Text PDFAn easily dispersible multiwalled carbon nanotube (MWCNT) derivative is prepared, and provides a platform for the synthesis of the phenyl butyric acid methyl ester (PCBM) analog. The carbene addition reaction of MWCNTs makes derivatives that are less soluble in organic solvents; by exploiting this differential solubility, PCBM analogs can be separated from the unreacted functionalized MWCNTs. Our experimental evidences indicate that it is the unique properties of the butyric acid methyl ester moiety that makes the acceptor material perform better in organic photovoltaics (OPVs).
View Article and Find Full Text PDFWe report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 ºC with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (∼10(-6) mbar) and 45 min to cool down without any extra cooling.
View Article and Find Full Text PDFThis paper reports the structural and optical properties of rare earth doped and codoped yttrium oxide nanophosphors. Dysprosium (Dy(3+)) and Terbium (Tb(3+)) doped and codoped yttrium oxide (Y2O3) phosphors were prepared by combustion synthesis method and subsequently annealed to high temperature to eliminate the hydroxyl group (-OH) and to get more crystallinity. The formation of compounds was confirmed by the X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR).
View Article and Find Full Text PDFHere, we report the development of a simple, small, fast heating, and portable, homemade, inert gas (Ar) atmospheric annealing setup. Instead of using a conventional heating element, a commercial soldering rod having an encapsulated fast heating heater is used here. The sample holder is made of a block of stainless steel.
View Article and Find Full Text PDFWe have developed multifunctional nanohybrids of poly(vinylidene fluoride-co-chlorotrifluoroethylene) (CTFE) with a small percentage of surface modified inorganic layered silicate showing dramatic improvement in toughness, radiation resistant and piezoelectric properties vis-à-vis pristine polymer. Massive intercalation (d(001) 1.8 → 3.
View Article and Find Full Text PDFWe report here nanotwin-core-shell Ni(core)NiO(shell) spheres of average size 25 nm prepared through polyol method. They exhibit high coercive field at 2 K, sharp peak at approximately 20 K in magnetization curve and magnetization reversal. Interestingly, exchange bias due to antiferromagnetic NiO shell is absent.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
August 2008
Temperature dependent magnetic and electronic properties of electron beam evaporated Fe/Al multilayer samples (MLS) with an average composition of Fe0.70A1(0.30) (MLS-A) and Fe0.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
June 2008
In the present paper, we have investigated structural, optical as well as electronic properties of electron beam evaporated Ge thin films having layer thicknesses ranging from ultra-thin (5 nm) to thick (200 nm). The Raman spectra show that all peaks are shifted towards lower wave number as compared to their bulk counterparts and are considered as a signature of nanostructure formation and quantum confinement effect. The Raman line exhibits transformation from nanocrystalline to microcrystalline phase with a reduction in blue shift of peak position with increase in Ge film thickness (>5 nm).
View Article and Find Full Text PDFThis investigation deals with the effect of growth temperature on the microstructure, nitrogen content, and crystallinity of C-N nanotubes. The X-ray photoelectron spectroscopic (XPS) study reveals that the atomic percentage of nitrogen content in nanotubes decreases with an increase in growth temperature. Transmission electron microscopic investigations indicate that the bamboo compartment distance increases with an increase in growth temperature.
View Article and Find Full Text PDFThis paper presents structural, magnetic, and transport properties measurements carried out on Co thin film as a function of thickness. The structure of the Co thin film changes from amorphous to nano-crystalline with the increase in film thickness. The corresponding magnetic and transport measurements show drastic changes in coercivity, saturation field and resistivity value as a function of Co film thickness.
View Article and Find Full Text PDFWe have investigated the effect of ferrocene concentration on the synthesis of carbon-nitrogen (C-N) nanotubes. The bamboo-shaped carbon-nitrogen nanotubes were synthesized by spray pyrolysis of Fe(C5H5)2 and CH3CN solution using argon as a carrier gas at the optimum temperature of approximately 900 degrees C. The effect of ferrocene concentration on the length and concentration of nitrogen in nanotubes was studied.
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