Papers by Keyword: Layered Compound

Abstract: Stable Eu³⁺ doped single-layer rare-earth oxide nanosheets sol were successfully obtained via exfoliation of layer Y_(1-X)Eu_xOBr in n-butanol solvent. After β-diketones modifying, novel inorganic/organic luminescent hybrids were successfully synthesized. At the mean time we discovered that the main charge transfer (Eu-O) excitation bands in nanosheets were replaced by more efficient π-π* electron transition excitation band s of the organic ligands in the hybrids. The emission bands of the ⁵D₀-⁷F₂ electric dipole transition in hybrids were enhanced greatly.

Abstract: We prepared a series of organic acids pillared layered rare earth compounds Y_2-xEu_x(OH)₅X·nH₂O (X= Organic acid) by hydrothermal reaction, The distance of layers was determined by X-ray diffraction, and discussed the relationship between the intercalated organic anion and the distance between the layers, In addition, the layered rare earth compound we prepared exhibited good fluorescence properties, being excited by ultraviolet light, the layered compound exhibited characteristic fluorescence spectra of Eu³⁺ ions. But the fluorescence intensity of the layered compound changed with different intercalated organic anions, by the ratio of the electric dipole transition and magnetic dipole transitions (⁵D₀-⁷F₂)/ (⁵D₀-⁷F₁), we studied the coordination environment of the luminescent center. And discussed the relationship between intercalated organic anions and fluorescence intensity.

Abstract: Layered Molybdenum trioxide M_OO₃, with a two-dimensional (2D) structure was successfully delaminated into colloidal nanosheets in n-butanol via a soft-chemical process involving intercalation of dodecylamine. X-ray diffration (XRD) showd that: after intercalation spacing of the layered material expend from 1.38nm to 2.69nm. Furthermore, stable nanosheet sol was obtained after exfoliation under ultrasonic condition, Characterizations by transmission electron microscopy (TEM) and scan electron microscopy (SEM) confirmed the formation of unilamellar 2D nanosheet crystallites with an average lateral size of 400 nm, those also suggests that the samples we got is Lamellar structured. Selected Area Electron Diffraction (SEDA) indicates that the obtained nanosheets were crystalline. And the obtained nanosheets exhibited photo-catalytic decolorization properties. Which was evaluated by monitoring the degradation of Methylene Blue, after 40 minutes 90% methylene blue was degradated.

Abstract: Layered Molybdenum trioxide M_OO₃, with a two-dimensional (2D) structure was successfully delaminated into colloidal nanosheets in n-butanol via a soft-chemical process involving intercalation of dodecylamine. X-ray diffration (XRD) showd that: after intercalation spacing of the layered material expend to 2.69nm from 1.38nm, and Characterizations by transmission electron microscopy (TEM) and scan electron microscopy (TEM) confirmed the formation of unilamellar 2D nanosheet crystallites with an average lateral size of 400 nm. The obtained nanosheets exhibited photochromic properties upon UV-VIS excitation. The chromogenic nanosheet obtained in this study features the intense UV absorption and optically switchable Visible-to-IR absorption, which may be useful for window applications such as heat-absorbing films.

Abstract: Gelatin has been successfully intercalated into monohydrate zirconium hydrogen phosphate in certain conditions by first inserting aminocaproic acid into its lattice followed by its replacement with gelatin.

Abstract: Tb³⁺ doped Yttrium hydroxide nanosheets were successfully synthesized from layer compound of Y₂(OH)₅NO₃ doped by Tb³⁺. Layer compound was obtained by hydrothermal reaction at 120°. After ion exchange reaction with sodium benzoate under the microwave condition, the layer space of the compound increases from 0.907 nm to 1.452 nm. stable nanosheets sol was obtained after exfoliation under ultrasonic condition. The structure of layer compound and the morphology of nanosheets were determined by XRD,SEM, Zeta Size, Zeta Potential, TEM and FL. The luminescence properties of terbium hydroxide nanosheets doped with Tb³⁺ were examined; the relationship between structure and spectra was discussed.

Abstract: The layered K₂La₂Ti₃O₁₀ photocatalyst was synthesized via a stearic acid method. The structure of the photocatalyst was determined by means of powder X-ray diffraction, scanning electron microscope and UV-Vis spectroscopy. The photocatalytic properties for hydrogen evolution of the photocatalyst were examined under ultraviolet irradiation. The results showed that, the sample which synthesized under 1000°C for 2 h via stearic acid method has the highest crystallinity and the amount of photocatalytic hydrogen production activity was 6.43 mmol/(g cat) under UV light irradiation for three hours.

Abstract: The Ti-Al composite electrode materials was prepared by hot press diffusion bonding in this article, and by the scanning electron microscopy (SEM), the energy dispersive spectroscopy (EDS), four-probe method, electrochemical workstation test means were used to test the structure and properties of the samples. The results show that the method of hot pressing diffusion sintering can achieve metallurgical bonding of Ti and Al with static pressure of 6MPa, holding times of 120min, in Ar and bonding temperature higher than 550°C,as well resistivity of the composite had dropped significantly, it was only 1/10 of pure Ti. The electrochemical properties of the composite electrode materials is also much better than pure Ti anode, and preparation conditions on electrochemical properties and the resistivity is consistent with law. This also shows that the conductivity of metal matrix will directly affect the catalytic properties of electrode materials for electrochemical. Therefore, changes in the composition of the electrode base material and structure not only reduces the cost and improve the performance of the electrode, also reached the purpose of energy saving.

Abstract: We have discovered a novel compound Na0.12CrO2Ge0.18Ox•yH2O using a hydrothermal method. Its powder X-ray diffraction reveals a monoclinic unit cell with lattice parameters: a = 7.260 Å, b = 2.950 Å, c = 5.117 Å and β = 103.7°. A Rietveld analysis shows that this compound has a layered structure based on CrO2 sheets consisting of edge-shared CrO6 octahedra. Such a layered structure is commonly seen in many hexagonal Cr oxides such as NaCrO2. A heat treatment at 100 °C modifies the crystal structure without destruction of a layered structure based on Cr triangular-lattice, because H2O molecules among the CrO2 sheets are removed at high temperature. Magnetization measurements reveal a spin-glass behavior below Tg = 3 K.

Abstract: Bi4-xLaxTi3O12 (where x = 0, 0.25, 0.50, 0.75 and 1) powders and ceramics were prepared using conventional solid state reaction and sintering procedures. The calcination was carried out at 750 °C for 4 h and sintering was done at 1150 °C for 4 h. The density of all ceramics was found to be comparable regardless of La concentration. X-ray diffraction analysis showed that preferred orientation of ceramic grains was reduced with addition of La ions. This reduced preferred orientation was accompanied by a decrease in grain size. The temperature dependence of dielectric constant showed a decrease in Tc with increasing La concentration.