Layered niobate KNb 3 O 8 synthesized by thepolymeric precursor method

Abstract The polymeric precursor method was used for the synthesis of KNb3O8 and compared to the solid-state method. The materials were characterized by X-ray diffraction (XRD), infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and determination of surface area and total pore volume by nitrogen isotherms at 77 K. The material prepared by the polymeric precursor method was single-phase while K2Nb4O11 was obtained as secondary phase when the solid-state method was used, as evidenced by the XRD patterns and the Raman spectra. The morphology of the materials was significantly altered by the synthesis method, as the KNb3O8 prepared by the polymeric precursor method presented a more porous morphology leading to a higher surface area and pore volume.

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Influence of Polyester Chain Type in the Morphology of Silica-Carbon Composites Obtained by the Polymeric Precursor Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.881.289 ◽

2016 ◽

Vol 881 ◽

pp. 289-294

Author(s):

Tiziana Azario de Medeiros ◽

Eliane Kujat Fischer ◽

Igor Silva de Sá ◽

Graciele Vieira Barbosa ◽

Margarete Soares da Silva ◽

...

Keyword(s):

Surface Area ◽

Pore Volume ◽

Molecular Sieves ◽

Particulate Composite ◽

Metallic Phase ◽

Carbon Composites ◽

Polymeric Precursor Method ◽

Polymeric Precursor ◽

Carbon Phase ◽

Precursor Method

Particulate composite materials containing metallic phase in ceramic matrices may be obtained by direct routes with the advantage of avoiding the partial collapse of the composite structure when a subsequent step for metal insertion is carried out. The non-metallic silica-carbon matrix combines high values of pore volume and surface area with chemical refractivity and may be applied as molecular sieves, adsorbents, filters and catalyst support. The Polymeric Precursor Method is a versatile method to obtain this composite type as the metal precursor can be reduced to metallic phase by pyrolysis of organic matter. In this work, it was used three different diol chain sizes obtaining silica-carbon composites through the pyrolysis of polyester precursor at 600°C for 3 hours in closed tubular oven. It was observed a direct dependence between the amorphous carbon phase amount and the polyester chain size. All of the composite samples presented dual distribution for mesopore size, situated at 3.8 and 11 nm in diameter. However, the pore volume and surface area significantly lowers for larger polyester chain sizes.

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Effect of Iron and Vanadium on the Phase Transition of Titanium Dioxide Obtained by Polymeric Precursor Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.881.18 ◽

2016 ◽

Vol 881 ◽

pp. 18-23

Author(s):

Eduardo Felipe de Carli ◽

Maycon dos Santos ◽

Natali Amarante da Cruz ◽

Daniela Cristina Manfroi ◽

Jusinei Meireles Stropa ◽

...

Keyword(s):

Phase Transition ◽

Titanium Dioxide ◽

Phase Formation ◽

Anatase Phase ◽

Synthesis Method ◽

Rutile Phase ◽

Polymeric Precursor Method ◽

Polymeric Precursor ◽

Precursor Method ◽

Powder Samples

The titanium dioxide phase formation is dependent on the synthesis method, temperature of calcination and modifiers insertion. By using chemical methods, such as Polymeric Precursor Method, the organic impurities or extrinsic defects caused by doping play an important rule on the formation of precursor structure before the phase crystallization above 500 oC. Some dopants can change the decomposition mechanism of the precursor, which affects the anatase-rutile phase transition. In this work, the Polymeric Precursor Method was used to synthesize titanium dioxide powder samples in order to investigate the effects of iron (III) and vanadium (V) dopants on the phase formation. Through thermal analysis of polymeric precursors and X-ray diffractometry for calcined powder samples it was possible to show the existence of antagonistic effects for both investigated dopants. While the iron doping reduces the anatase phase tetragonality and delays the rutile phase conversion, the vanadium one changes the mechanism of decomposition of polymeric precursor and leads to more amount of rutile phase.

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Photoluminescence property of powders prepared by solid state reaction and polymeric precursor method

Physica B Condensed Matter ◽

10.1016/j.physb.2009.05.014 ◽

2009 ◽

Vol 404 (20) ◽

pp. 3341-3347 ◽

Cited By ~ 42

Author(s):

S.K. Rout ◽

L.S. Cavalcante ◽

J.C. Sczancoski ◽

T. Badapanda ◽

S. Panigrahi ◽

...

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Photoluminescence Property ◽

Polymeric Precursor Method ◽

Polymeric Precursor ◽

Precursor Method

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Synthesis and Characterization Titanium Dioxide (TiO2) Doped Vanadium(V) Using Solid State Method

ALCHEMY ◽

10.18860/al.v4i1.3143 ◽

2015 ◽

Vol 4 (1) ◽

Author(s):

Khusnan Mustofa ◽

Nur Aini ◽

Susi Nurul Khalifah

Keyword(s):

Titanium Dioxide ◽

Solid State ◽

Band Gap ◽

Diffuse Reflectance Spectroscopy ◽

Synthesis Method ◽

Band Gap Energy ◽

Solid State Method ◽

Gap Energy ◽

Wavelength Absorption ◽

State Method

TiO2 Anatase activities should be increased from the UV to the visible light photocatalytic activity of TiO2 to increase anatas. One efforts to optimize TiO2 anatase activity is doping by using dopant vanadium(V). Synthesis method which is used in this research is a solid reaction method. The steps being taken in this methods include grinding and heating at high temperatures. Dopant concentrations of vanadium(V) which are used in the research was 0.3%, 0.5% and 0.7%. and the characterization used is X-ray diffraction and UV-Vis Diffuse Reflectance Spectroscopy. The result shows that there are a changing of particle size, band gap energy, and absorption of TiO2 anatas wavelength because of dopan vanadium(V) addition. While TiO2’s structure does not change. The crystal sizes of each TiO2 without doping, V-TiO2 0,3%, 0,5% and 0,7% are 53.21 nm, 47.67 nm, 79.65 nm dan 68.99 nm. Band gap energy of each TiO2 without doping, V-TiO2 0,3%, 0,5% dan 0,7% are 3.309 eV, 3.279 eV, 3.270 eV and 3.259 eV. While wavelength absorption of each TiO2 without doping, V-TiO2 0,3%, 0,5% and 0,7% are 374.9 nm, 378.4 nm, 379.5 nm and 380.8 nm. Keywords: Synthesis, titanium dioxide, vanadium(V), solid state method

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Dual Doping of Silicon and Manganese in Hydroxyapatites: Physicochemical Properties and Preliminary Biological Studies

Materials ◽

10.3390/ma12162566 ◽

2019 ◽

Vol 12 (16) ◽

pp. 2566 ◽

Cited By ~ 3

Author(s):

Katarzyna Szurkowska ◽

Agata Drobniewska ◽

Joanna Kolmas

Keyword(s):

Solid State ◽

Synthesis Method ◽

Precipitation Method ◽

Manganese Acetate ◽

Phase Identification ◽

Solid State Method ◽

X Ray ◽

Biological Studies ◽

Depth Analysis ◽

State Method

Silicated hydroxyapatite powders enriched with small amounts of manganese (Mn2+) cations were synthesized via two different methods: precipitation in aqueous solution and the solid-state method. The source of Mn2+ ions was manganese acetate, while silicon was incorporated using two different reagents: silicon acetate and sodium metasilicate. Powder X-ray diffraction (PXRD) analysis showed that the powders obtained via the precipitation method consisted of single-phase nanocrystalline hydroxyapatite. In contrast, samples obtained via the solid-state method were heterogenous and contaminated with other phases, (i.e., calcium oxide, calcium hydroxide, and silicocarnotite) arising during thermal treatment. The transmission electron microscope (TEM) images showed powders obtained via the precipitation method were nanosized and elongated, while solid-state synthesis produced spherical microcrystals. The phase identification was complemented by Fourier transform infrared spectroscopy (FTIR). An in-depth analysis via solid-state nuclear magnetic resonance (ssNMR) was carried out, using phosphorus 31P single-pulse Bloch decay (BD) (31P BD) and cross-polarization (CP) experiments from protons to silicon-29 nuclei (1H → 29Si CP). The elemental measurements carried out using wavelength-dispersive X-ray fluorescence (WD-XRF) showed that the efficiency of introducing manganese and silicon ions was between 45% and 95%, depending on the synthesis method and the reagents. Preliminary biological tests on the bacteria Allivibrio fisheri (Microtox®) and the protozoan Spirostomum ambiguum (Spirotox) showed no toxic effect in any of the samples. The obtained materials may find potential application in regenerative medicine, bone implantology, and orthopedics as bone substitutes or implant coatings.

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Influence of Oxidizing Atmosphere on Crystalline Phase Formation and Microstructural Properties of Mixed Cerium-Zinc Oxides Obtained by Polymeric Precursor Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.798-799.75 ◽

2014 ◽

Vol 798-799 ◽

pp. 75-78

Author(s):

L.L.M. Sales ◽

R.A. Candeia ◽

Fernando A.P. Cunha ◽

Jesana Moura Silva ◽

Alexsandra Cristina Chaves ◽

...

Keyword(s):

Surface Area ◽

Mixed Oxides ◽

Rietveld Method ◽

Xrd Analysis ◽

Polymeric Precursor Method ◽

Microstructural Properties ◽

Polymeric Precursor ◽

Precursor Method ◽

Oxidizing Atmosphere ◽

Catalytic Application

This paper presents the synthesis, characterization and influence of oxidizing atmosphere in the calcinations and sintering processes on microstructural properties of mixed oxides of Cerium and Zinc, obtained by the polymeric precursor method, aiming at a subsequent catalytic application. The material was submitted to calcinations and sintering at 900 and 1050 °C. The samples were characterized by XRD analysis techniques, surface area by BET method and refined by the Rietveld method. The results of X-ray diffraction showed that interest phase was formed, indicating that the method for obtaining the phase is effective. The results of surface area for the system calcined in air were 85 m2/g and 65 m2/g for the system subjected to oxidizing atmosphere both at 900°C, in the same temperature. It was observed that the temperature increase leads to an increase in crystallite size. This fact is in line with other studies in the literature.

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A facile synthesis method for fabrication of LaFeO3/g-C3N4 nanocomposite as efficient visible-light-driven photocatalyst for photodegradation of RhB and 4-CP

New Journal of Chemistry ◽

10.1039/c9nj03376a ◽

2019 ◽

Vol 43 (35) ◽

pp. 13783-13793 ◽

Cited By ~ 12

Author(s):

Mohammed Ismael ◽

Ying Wu

Keyword(s):

Solid State ◽

Visible Light ◽

Large Scale ◽

Synthesis Method ◽

Facile Synthesis ◽

Solid State Method ◽

Visible Light Driven ◽

Degradation Activity ◽

State Method ◽

Visible Light Photocatalytic

A solid state method for the large scale synthesis of LaFeO3/g-C3N4 nanocomposite with enhanced visible-light photocatalytic degradation activity.

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Preparation and Luminescent Properties of Green-Emitting La(BO3,PO4): Ce, Tb

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.105-106.359 ◽

2010 ◽

Vol 105-106 ◽

pp. 359-362

Author(s):

Li Min Dong ◽

Yan Li Zhuang ◽

Zhi Dong Han ◽

Ze Wu ◽

Xian You Zhang

Keyword(s):

Solid State ◽

Sol Gel ◽

Synthesis Method ◽

Morphological Structure ◽

Luminescent Properties ◽

Solid State Method ◽

Green Phosphor ◽

Gel Method ◽

Sol Gel Method ◽

State Method

Green phosphor of La(BO3, PO4): Ce, Tb was synthesized by means of sol-gel method and conventional solid state method. The thermal formation process was characterized by thermogravimetric analysis (TG) and (DTA). The effects of synthesis method and conditions on the crystal and morphological structure were investigated by (XRD) and (SEM). The results revealed that La (BO3, PO4): Ce, Tb phosphors with monocline structure and high purity were successfully prepared by sol-gel method. Compared with solid state method, the products synthesized by sol-gel method presented well developed crystal structure, small particle size, narrow size distribution and high luminescent performances. The product synthesized at 1050°C for 2h had better emission intensity.

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RuO2–IrO2 solid state micro-liquid film pH sensor based on polymeric precursor method

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209420 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 1047-1055

Author(s):

Hongli Ji ◽

Junjun Jia ◽

Chao Zhang ◽

Chongcong Tao ◽

Lu Yang ◽

...

Keyword(s):

Solid State ◽

Ph Value ◽

Ph Sensor ◽

Polymeric Precursor Method ◽

Polymeric Precursor ◽

Precursor Method ◽

Wide Ph Range ◽

Glass Type ◽

Ph Range ◽

High Level

The glass-type electrodes based pH sensors suffer from the weakness of fragility and poor stability in acid/alkali solution. To overcome these disadvantages, a novel solid-state pH sensor based on a RuO2–IrO2 H+ sensitive electrode via a polymeric precursor method was developed in this paper. The electrochemical performance of pH sensor was tested in different conditions. The experimental results showed that the sensitivity of the pH sensor could reach a high level of 52.0 mV/pH in a wide pH range of 2 ∼ 10. Furthermore, the response of pH sensor was fast and the response time remained less than 2.2 s even under varying pH conditions. The experiment was repeated three times during a period of time, the potential difference of pH sensor was between ±0.3 mV and ±0.9 mV in different pH value solutions, demonstrating its good stability, repeatability, recyclability and small potential drift. The negligible interference of Li+, Na+, K+, Ca2+, Mg2+, to the proposed pH sensor was also proven experimentally.

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