The W, V, Ce, Zr, Fe, and Cu metal ion substituted nanocrystalline anatase TiO2 was prepared by solution combustion method characterized XRD, Raman, BET, EPR, XPS, IR TGA, UV absorption, photoluminescence measurements. structural studies indicate that the solid formation limited to a narrow range of concentrations dopant ions. photocatalytic degradation 4-nitrophenol under solar exposure investigated with Ti1-xMxO2±δ. rates these catalysts were lesser than undoped both radiation. However,...

Nanocrystalline TiO2 was synthesized by the solution combustion method using titanyl nitrate and various fuels such as glycine, hexamethylenetetramine, oxalyldihydrazide. These catalysts are active under visible light, have optical absorption wavelengths below 600 nm, show superior photocatalytic activity for degradation of methylene blue phenol UV solar conditions compared to commercial TiO2, Degussa P-25. The higher is attributed structure catalyst. Various studies X-ray diffraction, Raman...

The frequency-dependent conductivity of laser-deposited ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ thin films shows an onset midinfrared absorption at \ensuremath{\sim}140 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ and structure in the 400--500-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ region. These low-energy absorptions occur both above below ${T}_{c}$, making them unlikely to be superconducting gap usual BCS sense. across...

The structure and chemical nature of Pt in combustion-synthesized Pt/CeO2 catalysts have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), photoelectron spectroscopy (XPS), extended absorption fine (EXAFS), temperature-programmed reaction (TPR). Catalytic oxidation CO over is correlated with its structure. High-resolution XRD studies show that the could be refined for composition Ce1-xPtxO2-δ fluorite 6% oxide ion vacancy. TEM images very few particles on...

The structure and chemical environment of Cu in Cu/CeO2 catalysts synthesized by the solution combustion method have been investigated X-ray diffraction (XRD), transmission electron microscopy (TEM), paramagnetic resonance (EPR) spectroscopy, photoelectron spectroscopy (XPS), cyclic voltammetry (CV), extended fine (EXAFS) spectroscopy. High-resolution XRD studies 3 5 atom % do not show CuO lines their respective patterns. could be refined for composition Ce1-xCuxO2-δ (x = 0.03 0.05; δ ∼ 0.13...

A 1% Pt/CeO2 catalyst prepared by the solution combustion method shows a higher catalytic activity for CO oxidation O2 compared to Pt metal particles. At least six hydrogen atoms are taken up per at −25 °C. The structure of has been investigated X-ray diffraction (XRD), transmission electron microscopy (TEM), photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. Rietveld refinement that ions incorporated into CeO2 matrix in form Ce1-xPtxO2-δ solid solution....

2000 Å as-deposited high Tc superconducting Y1Ba2Cu3O7−x films with zero-resistance temperatures of ∼89 K and critical current densities about 0.7×106 A/cm2 at 77 have been reproducibly fabricated a substrate holder temperature 650 °C, using pulsed laser deposition, no post-annealing. One key to these results is the injection gaseous oxygen into laser-produced plume just in front target. In this way, correct amount incorporated as-grown film so that post-deposition treatment becomes...

Oxidative precipitation in an aqueous medium of highly self-compacted crystallized Co3O4 dense nanoparticles (4−5 nm) leads to the formation porous micrometric agglomerates exhibiting a well-defined porosity distribution. Postannealing these powders induces drastic reorganizations first because fast removal trapped water and then particles sintering, resulting larger inter-particle voids. Electrochemical behavior this nanometric material precipitated at moderate temperature is found be...

The catalysts, Ti0.9M0.1O2-δ (M = Cr, Mn, Fe, Co, Cu), were synthesized in anatase phase by solution combustion. Selective catalytic reduction (SCR) of NO with NH3 was investigated over these catalysts. reaction occurred at the lowest temperature Ti0.9Mn0.1O2-δ, but selectivity for N2 highest Ti0.9Fe0.1O2-δ. Therefore, both Mn and Fe substituted TiO2 (Ti0.9Mn0.05Fe0.05O2-δ). low a high this catalyst. In order to understand mechanism nature active sites, programmed desorption (TPD) hydrogen...

We have grown ultrathin films of Y1Ba2Cu3O7−x in situ on (001) SrTiO3 by pulsed laser deposition. The zero resistance transition temperature (Tc0) is >90 K for >300 Å thick. critical current density (Jc at 77 K) 0.8×106 A/cm2 a 300 film and 4–5×106 1000 film. Tc0 Jc deteriorate rapidly below Å, reaching values 82 K, respectively, 100 Films only 50 thick exhibit metallic behavior possible evidence superconductivity without showing to 10 K. These results are understood the basis...

We have fabricated Josephson weak links from in situ laser-deposited four-layer structures of YBa2Cu3O7−x/PrBa2Cu3O7−x/YBa2Cu3O7−xAu. These devices show superconductor/normal-metal/superconductor-like current-voltage characteristics with good areal scaling both the critical currents Ic and resistances Rj, IcRj≊3.5 mV. Constant-voltage current steps observed response to 84 GHz mm-wave radiation modulation dc supercurrent a transverse magnetic field demonstrate that ac effects occur these devices.

X-ray photoelectron spectroscopy reveals that the remarkable electronic quality of GaAs/sulfide interfaces can be ascribed to formation AsxSy phases which grow on an oxide-free GaAs surface. While one these is akin As2S3, another shows significant in-plane S—S bonding. Raman experiments indicate band bending this disulfide- terminated surface has been reduced 0.12 eV.

The ${\mathrm{Bi}}_{4}$${\mathrm{Sr}}_{4}$${\mathrm{Ca}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{R}}_{\mathit{x}}$${\mathrm{Cu}}_{4}$${\mathrm{BO}}_{\mathit{y}}$ materials (R is a rare-earth element) were studied to determine their structural and physical properties. For most of the elements, complete solid solution exists up x=2. Below x=0.5,${T}_{c}$ not affected for each added element we find that about 0.5 oxygen atom structure. However, modulation observed along b axis undoped...

High-performance, all-aromatic, insoluble, engineering thermoplastic polyimides, such as pyromellitic dianhydride and 4,4'-oxydianiline (PMDA-ODA) (Kapton), exhibit exceptional thermal stability (up to ≈600 °C) mechanical properties (Young's modulus exceeding 2 GPa). However, their resistance, which is a consequence of the all-aromatic molecular structure, prohibits processing using conventional techniques. Previous reports describe an energy-intensive sintering technique alternative for...

Systematics in the X-ray photoelectron spectra (X. p. e. s.) of Ti, V, Cr, Mn and Nb oxides with metal ion different oxidation states as well related series mono-, sesqui- di-oxides first row transi­tion metals have been investigated detail. Core level binding energies, spin-orbit splittings exchange are found to exhibit inter­esting variations state or nuclear charge The 3d energies monoxides show a proportionality Goodenough’s ( R — c ). Other aspects interest study satellite structure...

Ce1−xSnxO2 (x = 0.1−0.5) solid solution and its Pd substituted analogue have been prepared by a single step combustion method using tin oxalate precursor. The compounds were characterized X-ray diffraction (XRD), photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), H2/temperature programmed redution (TPR) studies. cubic fluorite structure remained intact up to 50% of Sn substitution in CeO2, the stable 700 °C. Oxygen storage capacity was found be much higher than that...

Platinum nanoparticles with average diameters of 2−3 nm have been coated on multiwalled carbon nanotubes by controlled attachment an intermediate the walls nanotube. Reduction leads to formation platinum which are uniformly nanotubes. This composite shows excellent electrocatalytic activity toward methanol oxidation and hence is a candidate material for fuel cell applications. Cyclic voltammetry chronoamperometry studies indicate that these composites better compared commercial Pt−carbon...

Epitaxial LaNiO3(LNO) thin films on LaAlO3(LAO), SrTiO3(STO), and YSZ are grown by pulsed laser deposition method at 350 mTorr oxygen partial pressure 700 °C substrate temperature. As-deposited LNO metallic down to 10 K. c-axis oriented YBa2Cu3O7 (YBCO) were LNO/LAO as well LNO/STO surfaces without affecting superconducting transition temperature of YBCO. Textured YBCO/STO YBCO/YSZ . Transport measurements these bilayer showed that is a good contact material for

Ionically dispersed Rh over CeO2 in Rh/CeO2 catalysts prepared by a single step solution combustion method is shown to improve the redox property and catalytic activity. The H2/Rh ratio obtained from hydrogen uptake measurement was 5.4, 2.4, 2.1, respectively 0.5, 1, 2% Rh/CeO2, indicating significant contribution reduction of presence Rh. In 1% light-off temperature for CO oxidation about 80 °C lower compared metal 190 than that Rh2O3. enhanced activity catalyst has been correlated with...