Comparative studies on synthesis of nanocrystalline Sc2O3–Y2O3 doped zirconia (SYDZ) and YSZ solid solution via modified and classic Pechini method

Abstract

Nanocrystalline tetragonal Sc 2 O 3 (3.5 mol%) and Y 2 O 3 (0.5 mol%) doped zirconia (SYDZ and YSZ) solid solutions were prepared by modified and classic Pechini method, respectively. In this approach, zirconium oxynitrate, scandium and yttrium nitrate, citric acid (CA) and ethylene glycol monobutyl ether (EGM) were used as the sources of Zr 4+ , Sc 3+ , Y 3+ , and the chelating and solvent agents, respectively. The SYDZ nanocrystals, synthesized with a 1Zr 4+ : 4EGM : 4CA mole ratio in acidic medium (pH y1) at 700 uC, had a smaller particle size (15 ¡ 3 nm) than YSZ synthesized with the classic Pechini method. Also, our optimized synthesis was applied to a large scale elaboration by increasing the quantity of precursors. Finally, The optical properties of SYDZ nanocrystals were also investigated by UV-vis spectroscopy.

Synthesis of mesoporous and tetragonal zirconia with inherited morphology from metal–organic frameworks

“…[26][27][28] On the other hand, the stabilization of the tetragonal phase of zirconia mainly depends on its surface free energy. With the escape of organic groups, the octahedral zirconia is reserved.…”

Synthesis of TiO2−xNy/Ag‐PbMoO4 Composite and Their Photocatalytic Activity Under Simulated Solar Light Irradiation

“…TiO 2− x N y exhibits small broad peak (101) in prepared TiO 2− x N y /Ag‐PbMoO 4 composite which confirms the anatase phase, while Ag‐PbMoO 4 peaks are tetragonal scheelite crystalline structure. The average crystallite sizes of all samples are calculated by Scherrer's equation based on the diffraction peak corresponding to the (101) plane of TiO 2 and (112) plane of TiO 2− x N y /Ag‐PbMoO 4 composite . Crystallite size of different photocatalysts is listed in Table .…”

Characterization of CBD-CdSe1-ySy deposited at low-temperature for photovoltaic applications

“…2b shows the deconvolution of Xray diffractograms of typical samples M100 and M730, which were deposited with 0 and 30 ml of thiourea in the growth solution, to find all the diffraction peaks that make up the X-ray diffractograms. The crystallite sizes (D(hkl)) were calculated from the line broadening of the X-ray diffraction peaks at 2θ using the Debye-Scherrer equation, [20,21]. The lattice parameters of CdSe 1-y S y and the mean grain sizes are presented in Table 2.…”

“…The absorption coefficient α for a film of thickness d and reflectance R is determined near the absorption edge using the simple relation: α = ln{(1-R) 2 /T+[((1-R 2 )/2T) 2 +R 2 ] 1/2 }/d, where multiple reflections are taken into, but interference neglected. Actually a transmission interference pattern could be observed in most samples, and was used to obtain an accurate value for the thickness d. The optical band gap of CdSeS has been evaluated from the transmittance spectrum using the Tauc relation[20,28,29]:, where n depends on the kind of optical transition that prevails. Specifically, n is 1/2 and 2 when the transition is directly and indirectly allowed, respectively.…”