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Nano powders can show excellent photocatalytic properties due to its large surface to volume ratio. The samples of cubic Y2O3 annealed at 650°C for 4 h at a heating rate of 2°C/min. were prepared by Pechini type sol-gel technique. The chemical composition of the as prepared and annealed sample has been confirmed by XRD. Debye-Scherrer formula is used to compute average crystallite size. FTIR analysis has also confirmed the Y-O vibrations in the sample. Optical analysis was also performed to study the annealing effect of the powder. A sharp Gaussian peak at 270 nm is observed in the annealed sample due to charge transfer state. The effect of nanopowder catalyst on degrading the MB dye is also studied. Y2O3 nanopowder is found to have good capacity to degrade MB dye. [ABSTRACT FROM AUTHOR]

We have synthesized CdO nanocrystallites by the simple co-precipitate method. Influence of different transition metal ions (Cu, Mn, Cu-Mn) have been investigated on their structural morphology by XRD, FTIR, and SEM-EDS. XRD revealed that rocksalt CdO crystalline structure has been appeared in all samples after heat treatment (750°C for 3h). The chemical bonding and IR vibrations are confirmed by Fourier Transform Infrared (FTIR). SEM micrographs exhibited different morphologies corresponding to each dopant. Undoped sample has homogenous powder with grassy texture, Cu doped sample has flacks like structure, Mn doped has rod- like shape while Cu-Mn doped sample has almost spherical morphology. The analysis of elemental composition for each sample suggests the appropriate doping of transition metals (Cu, Mn & Cu-Mn). Various structural parameters like 'd' spacing; lattice parameters 'a', microstrain, and dislocation density is also calculated. This is further confirming the crystallographic modification appeared in CdO due to doping of Cu, Mn and Cu-Mn transition metal ions. The prepared doped metal oxides have numerous scientific and technological application awing to their unique properties specifically in Photovoltaic/Conductive devices. [ABSTRACT FROM AUTHOR]

Powder form of Yb/SiO2 in the form of nanorods are formulated by wet chemical techniques. This paper evaluates the physical and optical properties of Yb doped SiO2 nanorods prepared by the sol-gel method. The constituents are evaluated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), and Ultraviolet-visible spectroscopy (UV-Vis). In the XRD pattern, the manufactured tasters show the cubic phase of Yb2O3, with particle size ranging from 10 to 25 nm which is well-matched with the result of the SEM. The FTIR spectroscopy offers an infrared spectrum of absorption or emanation of materialistic forms. It assembles high-resolution information over an eclectic spectral array for a prepared sample. UV-Visible spectroscopy helps out the optical band gap value 4.43eV of Yb/SiO2 Powder. [ABSTRACT FROM AUTHOR]

Highly crystalline MgAl2O4nanopowder has been prepared by viable citrate sol-gel technique. We have annealed the sample at a thermal treatment i.e. 800°C and further compared the results with as-prepared sample. Crystallinity of the annealed sample isinvestigated by XRD, FTIR, and SEM-EDS. XRD analyzed the cubic spinel aluminates with lattice parameters 'a' = 0.8 nm with well defined reflection planes. Fourier Transform Infrared Spectroscopy depicted the chemical bonding and IR vibrations of the specific metal-oxygen bond. SEM micrographs further exhibited different shapes and texture of as-prepared and annealed nanopowder. The analysis of elemental composition for both samplesis evaluated by EDS spectra. The bandgap energy of as-prepared samples is (5.07 eV) found higher while that of annealed sample is low (1.8 eV). It is suggested that the annealed narrow band gap MgAl2O4 nanopowder is most crystalline and highly dense which is useful inphotocatalystsand advanced photonic devices. [ABSTRACT FROM AUTHOR]

Powder sample of Gd2O3:Dy3+ nano-phosphor was synthesized by citrate sol-gel technique. The synthesized sample was annealed at 650°C for 4 h at a rate of 2°C/min. Structural and optical investigations of pristine and annealed samples were carried out with the help of XRD, FTIR, FESEM, EDS and Photoluminescence (PL) spectra. Crystallite size, lattice parameter and micro-strain of cubic Gd2O3:Dy3+ were evaluated by Debye-Scherrer equation and Williamson-Hall Equation, respectively. Nelson-Riley and Bradley-Jay plotswere utilized for precise measurement of lattice parameter. In optical investigations, intense blue emissions at 486 nm and yellow emission at 572 nm was observed in pristine sample. It is observed that the intensity of characteristic emission in annealed sample has been enhanced with slight shift in their position may be due to increased number of defect states. [ABSTRACT FROM AUTHOR]