Microwave-Assisted Solid State Synthesis of Red-Emitting BCNO Phosphor and its Characteristics

2014 ◽  
Vol 896 ◽  
pp. 464-467 ◽  
Author(s):  
Bebeh Wahid Nuryadin ◽  
Ea Cahya Septia ◽  
Ferry Iskandar ◽  
Takashi Ogi ◽  
Kikuo Okuyama ◽  
...  
Keyword(s):  
Solid State ◽  
Uv Light ◽  
Hexagonal Boron Nitride ◽  
Low Cost ◽  
Broad Emission Band ◽  
Photoluminescence Properties ◽  
Carbon And Nitrogen ◽  
Microwave Assisted ◽  
Carbon And Nitrogen Content ◽  
Multi Phase

Red-emitting BCNO phosphor has been synthesized by a microwave-assisted solid state reaction using a low-cost boric acid, urea and polyethylene glycol (PEG-20k) as the starting materials. The effects of reaction parameters: temperature, carbon and nitrogen content on material composition and photoluminescence properties were investigated. Nearly multi-phase hexagonal boron nitride, boron oxide, boron carbide and carbon graphite was observed, indicating the BCNO were successfully synthesized. The photoluminescence spectra of the phosphor excited by a UV light (365 nm) showed a broad emission band at 460 - 620 nm.

scholarly journals Short Time and Low Temperature Reaction between Metal Oxides through Microwave-Assisted Hydrothermal Method

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
S. M. V. Novais ◽  
P. C. R. Silva ◽  
Z. S. Macedo ◽  
L. B. Barbosa
Keyword(s):  
Low Temperatures ◽  
Hydrothermal Reaction ◽  
Low Cost ◽  
Broad Emission Band ◽  
Time Saving ◽  
Cadmium Tungstate ◽  
Microwave Assisted ◽  
Solid State Route ◽  
Broad Emission ◽  
Short Time

This work demonstrates the possibility of synthesis of cadmium tungstate at low temperatures using oxide precursors. Cadmium tungstate (CdWO4) scintillator was produced via microwave-assisted hydrothermal reaction using the precursors CdO and WO3. The methodology was based on microwave radiation for heating, which is remarkably faster than the solid-state route or conventional hydrothermal procedure. CdWO4 monoclinic (wolframite) structure was successfully obtained at 120°C for synthesis times as short as 20 min. This route does not require the use of templates or surfactants and yields self-assembled nanorods with size of around 24 ± 9 nm width and 260 ± 47 nm length. The growth mechanism for the formation of CdWO4 involves microwave-induced dissociation of the reagents and solvation of Cd2+ and WO42- ions, which are free to move and start the nucleation process. The luminescence properties of the produced nanoparticles were investigated, presenting a broad emission band at around 500 nm, which is comparable to that observed for samples produced using other chemical routes. This result highlights the great potential of the proposed method as a low-cost and time saving process to fabricate luminescent oxide nanoparticles.

scholarly journals Evaluation of agricultural byproducts for the production of betaglucosidase by Aspergillus niger MBT-2 using solid state fermentation

2020 ◽  
Vol 49 (1) ◽  
pp. 135-140
Author(s):  
Roheena Abdullah ◽  
Maria Hanif ◽  
Afshan Kaleem ◽  
Mehwish Iqtedar ◽  
Kinza Nisar ◽  
...  
Keyword(s):  
Solid State ◽  
Aspergillus Niger ◽  
Solid State Fermentation ◽  
Low Cost ◽  
Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Enhanced Production ◽  
Enzyme Productivity ◽  
Valuable Product ◽  
By Products

The experiment was conducted to isolate and screen fungal strain and optimization of solid-state fermentation conditions for enhanced production of β-glucosidase. Different fungal cultures were isolated and screened for β-glucosidase production. The physicochemical and nutritional parameters were optimized for enhanced production of β-glucosidase from higher producer. Among all the isolates the isolate which exhibited highest β-glucosidase potential was identified and assigned the code as Aspergillus niger MBT-2. The optimum β-glucosidase production was obtained in M5 medium containing wheat bran after 72 hrs of incubation at 40°C, pH 6 and 20 ml of moisture contents. In addition to this 2% fructose and 2% yeast extract proved to be best carbon and nitrogen sources, respectively and gave maximal enzyme productivity. The exploitation of agricultural by products as a substrate reduced the production cost of enzyme and makes the process economical. The Aspergillus niger MBT-2 has promising potential of bioconversion of low-cost material into valuable product like β-glucosidase.

scholarly journals Yellow Emission Obtained by Combination of Broadband Emission and Multi-Peak Emission in Garnet Structure Na2YMg2V3O12: Dy3+ Phosphor

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 542 ◽  
Author(s):  
Weiyi Zhang ◽  
Can He ◽  
Xiaowen Wu ◽  
Ximing Huang ◽  
Fankai Lin ◽  
...  
Keyword(s):  
Solid State ◽  
White Light ◽  
Emission Band ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Color Temperature ◽  
Broad Emission Band ◽  
Yellow Emission ◽  
Conventional Solid State Reaction ◽  
Broad Emission

The fabrication and luminescent performance of novel phosphors Na2YMg2V3O12:Dy3+ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na2YMg2V3O12 host self-activated and released a broad emission band (400–700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO4)3− groups. Meanwhile, the Na2YMg2V3O12:Dy3+ phosphors emitted bright yellow light within both the broad emission band of the (VO4)3- groups and the sharp peaks of the Dy3+ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na2YMg2V3O12:Dy3+ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y2O3:Eu3+ red phosphors, and BaMgAl10O17:Eu2+ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na2YMg2V3O12:Dy3+ phosphor as a yellow-emitting phosphor in solid-state illumination.

A new stepped tetranuclear copper(II) complex: synthesis, crystal structure and photoluminescence properties

2017 ◽  
Vol 73 (5) ◽  
pp. 393-398 ◽  
Author(s):  
Elif Gungor
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Uv Light ◽  
Visible Region ◽  
Blue Emission ◽  
Green Emission ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Ft Ir

Binuclear and tetranuclear copper(II) complexes are of interest because of their structural, magnetic and photoluminescence properties. Of the several important configurations of tetranuclear copper(II) complexes, there are limited reports on the crystal structures and solid-state photoluminescence properties of `stepped' tetranuclear copper(II) complexes. A new CuII complex, namely bis{μ3-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}bis{μ2-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}tetracopper(II), [Cu4(C11H13NO3)4], has been synthesized and characterized using elemental analysis, FT–IR, solid-state UV–Vis spectroscopy and single-crystal X-ray diffraction. The crystal structure determination shows that the complex is a stepped tetranuclear structure consisting of two dinuclear [Cu2(L)2] units {L is 3-[(4-methoxy-2-oxidobenzylidene)amino]propanolate}. The two terminal CuII atoms are four-coordinated in square-planar environments, while the two central CuII atoms are five-coordinated in square-pyramidal environments. The solid-state photoluminescence properties of both the complex and 3-[(2-hydroxy-4-methoxybenzylidene)amino]propanol (H2 L) have been investigated at room temperature in the visible region. When the complex and H2 L are excited under UV light at 349 nm, the complex displays a strong blue emission at 469 nm and H2 L displays a green emission at 515 nm.

Synthesis and Photophysical Properties of Crosslinkable Multi-Branched Ethynyl Fluorene-Labeled Molecules

2012 ◽  
Vol 486 ◽  
pp. 211-213
Author(s):  
Xiao Dan Hu ◽  
Shao Hong Wang ◽  
Zhao Xia Hou
Keyword(s):  
Solid State ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Uv Light ◽  
Low Cost ◽  
Photophysical Properties ◽  
Solid State Lighting ◽  
Full Color ◽  
Color Displays

The simple way to synthesize crosslinkable multi-branched ethynyl fluorene-labeled molecules has been reported in this work. A three-armed molecule, OxDBFP is prepared by cyclotrimerization and phase transfer catalysis methods. 3-(6-Bromo-2-oxahexyl)-3-methyloxetane tethered to 9-position of fluorene is crosslinked when exposed to UV light. This kind of compounds can be proper candidates for full-color displays or solid-state lighting by low-cost solution prosessing.

Decolorisation of natural organic matter by Phanerochaete chrysosporium: the effect of environmental conditions

2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Phanerochaete Chrysosporium ◽  
Fungal Growth ◽  
Low Ph ◽  
Colour Removal ◽  
Humic Material ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Content

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.

The Structure and Photochromism of 2,4,4,6-Tetraphenyl-4H-thiopyran

1992 ◽  
Vol 57 (6) ◽  
pp. 1326-1334 ◽  
Author(s):  
Jaroslav Vojtěchovský ◽  
Jindřich Hašek ◽  
Stanislav Nešpůrek ◽  
Mojmír Adamec
Keyword(s):  
Solid State ◽  
Uv Light ◽  
Order Reaction ◽  
Boat Conformation ◽  
X Rays ◽  
Exponential Time ◽  
First Order ◽  
Double Plane ◽  
The Mean ◽  
Independent Molecules

2,4,4,6-Tetraphenyl-4H-thiopyran, C29H22S, orthorhombic, Pna21, a = 17.980(4), b = 6.956(2), c = 34.562(11) Å, V = 4323(2) Å3, Z = 8, Dx = 1.237 g cm-3, F(000) = 1696, λ(CuKα) = 1.54184 A, μ = 1.372 mm-2, T = 294 K. The final R was 0.050 for the unique set of 3103 observed reflections. The central 4H-thiopyran ring forms a boat conformation for both symmetrically independent molecules with average boat angles 4.4(3) and 6.8(3)° at S and C(sp3), respectively. The mean planes of phenyls at the position 2 and 6 are turned from the double plane of 4H-thiopyran by 42.5(5) and 35.8(3)°, respectively. The investigated material undergoes a photochromic change in the solid state after irradiation with UV light or X-rays. The maximum of the new absorption band is situated at 564 nm. The non-exponential time dependence of photochromic bleaching is analysed in terms of a dispersive first-order reaction.

scholarly journals Preparation of Zn-MOFs by microwave-assisted ball milling for removal of tetracycline hydrochloride and Congo red from wastewater

2021 ◽  
Vol 10 (1) ◽  
pp. 125-133
Author(s):  
Qinhui Ren ◽  
Fuhua Wei ◽  
Hongliang Chen ◽  
Ding Chen ◽  
Bo Ding
Keyword(s):  
Ball Milling ◽  
Congo Red ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Tetracycline Hydrochloride ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
Wastewater Purification ◽  
Microwave Assisted ◽  
Metal Organic

Abstract In this study, we prepared Zn-MOFs as an ordinary, low-cost, and efficiency method taking advantage of zinc(ii) acetate monohydrate and 1,3,5-benzenetricarboxylic acid in microwave-assisted ball milling. The Zn-MOFs were measured via scanning electron microscopy, infrared spectrometry, X-ray diffraction, and thermogravimetry. We explored its use as a photocatalyst for the degradation of tetracycline hydrochloride and Congo red from aqueous solutions. The results demonstrate that the kinetic model was appropriate for the removal of organic pollutants. In general, it is feasible, inexpensive, and effective to use metal organic framework (MOF) to treat waste liquid. Therefore, our findings indicate that Zn-MOFs have broad application vista in wastewater purification.

Sign in / Sign up

Export Citation Format

Share Document