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Characterization of nanocrystalline LiNi1-xCoxVO4 prepared by the polymerized complex method

Thongtem W. T., Phuruangrat A., Thongtem S.

Materials Science Poland

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2009

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Vol. 27, No. 1

43--49

EN

Nanocrystalline LiNi1-xCoxVO4 (x = 0.00, 0.25, 0.50, 0.75 and 1.00) was prepared from Li2CO3, Ni(NO3)2.6H2O, Co(NO3)2.6H2O and NH4VO3, using tartaric acid as a complexing agent, followed by 450 °C calcination for 12 h. TGA results show that nanocrystallites started to form at 450-550 °C. Inverse spinel LiNi1-xCoxVO4 was detected using the XRD and SAED methods. The calculated lattice parameter increased upon increasing Co concentration. It was in accordance with the increase in the particle size determined using TEM images. A stretching band of VO4 tetrahedra was detected at 651-820 cm-1 using FTIR. V-O vibrational bands analyzed with a Raman spectrometer were shifted to the lower wavenumbers, due to the increase of Co concentration. The selected elements were also analyzed using EDX and AAS to determine the stoichiometric values (x) of the oxides.

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Synthesis and characterization of metastable CeO2-ZrO2 solid solution obtained by polymerized complex method

Miśta W., Rayment T., Hanuza J., Macalik L.

Materials Science Poland

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2004

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Vol. 22, No. 2

153--170

EN

The paper describes the preparation and characterization of nano-size metastable tetragonal CeO2–ZrO2 mixed oxides prepared by a polymerized complex method. A glycine–ethylene glycol solution containing Ce3+ and Zr4+ ions was polymerized at 80–110 °C to form a viscous transparent resin without any visible precipitation. After heat-treatment at relatively low temperature (ca 250 °C) on a hot plate in static air, the solid precursor ignited in part due to self-combustion, resulting in the formation of a nanocrystalline, compositionally-homogeneous solid solution. Its structure was confirmed using X-ray diffraction, HRTEM and Raman spectroscopy. The phase separation in CeO2–ZrO2 system on a subsequent heat-treatment in air and in a mixture of H2 and He was also investigated up to 1100 °C.

3

Characterization and catalytic properties of CeO2-ZrO2 solid solution.

Miśta W., Rayment T., Zawadzki M.

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje

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1999

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Vol. 9, nr 56

237-241

EN

The nanocrystalline, metastable tetragonal (t') ceria-circonia solid solution were prepared by the polymerized complex method at a relatively low temperature. The as prepared transparent homogenous hybrid inorganic precursors can be also used in thin film applications. The solid materials were characterized by XRD, TEM, DTA/TG and nitrogen adsorption method. The catalytic activity of Pt/CeO2-ZrO2 catalyst in total oxidation of iso-butene and possibility of the gasification of graphite were evaluated.

PL

Otrzymano nanokrystaliczne, metastabilne roztwory stałe Ce)2-ZrO2 o strukturze tatragonalnej (t') za pomocą metody 'polimerycznej' w wyjątkowo niskich temperaturach. Tak otrzymane klarowne, homogenne nieorganiczno-organiczne prekursory mogą być zastosowane do nanoszenia cieńkich filmów. Materiały lite charakteryzowano za pomocą technik XRD, TEM, DTA/TG oraz niskotemperaturowej adsorpcji azotu. Określono aktywność katalityczną katalizatorów Pt/CeO2-ZrO2 w całkowitym spalaniu izo-butenu oraz możliwość zgazowania grafitu.