scholarly journals A highly sensitive fluorescent sensor for Al3+ detection based on luminescent Eu(III)-β-dicetonate complexes

2021 ◽  
Vol 63 (11) ◽  
pp. 47-50
Author(s):  
Thi Hien Dinh ◽  
◽  
Thi Mai Huong Phan ◽  
Duc Manh Nguyen ◽  
Luu Tung Quan Nguyen ◽  
...  
Keyword(s):  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Fluorescent Sensor ◽  
X Ray Diffraction ◽  
Sodium Complex ◽  
Simple Process ◽  
X Ray ◽  
Low Concentrations ◽  
Highly Sensitive ◽  
The Eu

The structure of the Eu(III) complexes were determined by single-crystal X-ray diffraction. The results showed that these complexes exist as a heteronuclear of Eu(III)-Na(I) in which ion Eu3+ is coordinated through eight oxygen atoms of four β-dixetone ligands. The authors found that the monomeric europium-sodium complex displays a very strong red emission with a quantum yield up to 47.5% at λex=370 nm. The authors have successfully designed a simple process to put the Eu(III) complexes on anion exchange resin to create Resin-EuTFNB and Resin-EuTFPB materials. The products have a luminescent intensity that is stronger than that of the precursor complexes due to the removal of the coordination solvents in these complexes. Initially, using these materials to test the ability to recognise Al3+ ion at low concentrations, Resin-EuTFNB and Resin-EuTFPB played a role as a sensing chemosensor based on turn-off mechanism. In the future, they are expected to detect Al3+ion in the biological system.

scholarly journals SnO2/TiO2 Thin Film n-n Heterostructures of Improved Sensitivity to NO2

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6830
Author(s):  
Piotr Nowak ◽  
Wojciech Maziarz ◽  
Artur Rydosz ◽  
Kazimierz Kowalski ◽  
Magdalena Ziąbka ◽  
...  
Keyword(s):  
Thin Film ◽  
Operating Temperature ◽  
Incidence Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Langmuir Blodgett ◽  
Response Recovery ◽  
Low Concentrations ◽  
Highly Sensitive ◽  
Recovery Times

Thin-film n-n nanoheterostructures of SnO2/TiO2, highly sensitive to NO2, were obtained in a two-step process: (i) magnetron sputtering, MS followed by (ii) Langmuir-Blodgett, L–B, technique. Thick (200 nm) SnO2 base layers were deposited by MS and subsequently overcoated with a thin and discontinuous TiO2 film by means of L–B. Rutile nanopowder spread over the ethanol/chloroform/water formed a suspension, which was used as a source in L–B method. The morphology, crystallographic and electronic properties of the prepared sensors were studied by scanning electron microscopy, SEM, X-ray diffraction, XRD in glancing incidence geometry, GID, X-ray photoemission spectroscopy, XPS, and uv-vis-nir spectrophotometry, respectively. It was found that amorphous SnO2 films responded to relatively low concentrations of NO2 of about 200 ppb. A change of more than two orders of magnitude in the electrical resistivity upon exposure to NO2 was further enhanced in SnO2/TiO2 n-n nanoheterostructures. The best sensor responses RNO2/R0 were obtained at the lowest operating temperatures of about 120 °C, which is typical for nanomaterials. Response (recovery) times to 400 ppb NO2 were determined as a function of the operating temperature and indicated a significant decrease from 62 (42) s at 123 °C to 12 (19) s at 385 °C A much smaller sensitivity to H2 was observed, which might be advantageous for selective detection of nitrogen oxides. The influence of humidity on the NO2 response was demonstrated to be significantly below 150 °C and systematically decreased upon increase in the operating temperature up to 400 °C.

Hydrogen Sensing Properties of Dye-Sensitized TiO2 Nanotube Array

2011 ◽  
Vol 492 ◽  
pp. 296-299 ◽  
Author(s):  
Liang Huang ◽  
Yun Han Ling ◽  
Yu Qing Zhuo ◽  
Fu Jian Ren
Keyword(s):  
Electrochemical Anodization ◽  
X Ray Diffraction ◽  
Nanotube Array ◽  
X Ray ◽  
Simulated Solar Light ◽  
Hydrogen Sensing ◽  
Dye Sensitized ◽  
Solar Light Irradiation ◽  
Low Concentrations ◽  
Highly Sensitive

A dye-sensitized TiO2 nanotube array (DST) was fabricated by electrochemical anodization in an aqueous organic electrolyte and immersed into ethanol containing N719 dye. The crystal phase and microstructure of the TiO2 nanotube array (TNTA) were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The UV-Vis spectra of the DST were characterized by diffuse reflectance spectra (DRS). The hydrogen sensitivity of the as-prepared sample was tested at room temperature under Xe-lamp (simulated solar light) irradiation. It was found that the sensor was highly sensitive to low concentrations of hydrogen as an application in air quality control.

Adsorption Capacity of Y Zeolite Using Organic Solvents such as Adsorbates

2014 ◽  
Vol 805 ◽  
pp. 641-645
Author(s):  
Ana Paula Araújo ◽  
Aline Cadigena Lima Patrício ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Small Molecules ◽  
Adsorption Capacity ◽  
Selective Adsorption ◽  
X Ray Diffraction ◽  
Y Zeolite ◽  
High Adsorption ◽  
X Ray ◽  
Low Concentrations ◽  
Adsorption Of Nitrogen ◽  
Type Zeolite

The zeolites differ from traditional adsorbents for selective adsorption of small molecules, the high adsorption capacity at low concentrations and affinity for organic compounds and unsaturated polar molecules. In this work a Y-type zeolite was synthesized, characterized by x-ray diffraction, scanning electron microscopy and adsorption of nitrogen and subjected to test adsorption capacity where it was found that the Y zeolite has the potential adsorption capacity compared to other materials being studied and marketed.

scholarly journals Investigations of M3Al8O15:Eu3+,Dy3+ (M = Ba, Ca, Mg) phosphors

2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk
Keyword(s):  
Electron Microscopy ◽  
Solid State Reaction Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Three Samples ◽  
Scanning Electron ◽  
The Eu

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.

scholarly journals Electronic and Crystallographic Examinations of the Homoepitaxially Grown Rubrene Single Crystals

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1978 ◽  
Author(s):  
Yasuo Nakayama ◽  
Masaki Iwashita ◽  
Mitsuru Kikuchi ◽  
Ryohei Tsuruta ◽  
Koki Yoshida ◽  
...  
Keyword(s):  
Single Crystals ◽  
Valence Band ◽  
Lattice Distortion ◽  
Grazing Incidence ◽  
Valence Band Maximum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homoepitaxial Growth ◽  
Highly Sensitive ◽  
Doping Ratio

Homoepitaxial growth of organic semiconductor single crystals is a promising methodology toward the establishment of doping technology for organic opto-electronic applications. In this study, both electronic and crystallographic properties of homoepitaxially grown single crystals of rubrene were accurately examined. Undistorted lattice structures of homoepitaxial rubrene were confirmed by high-resolution analyses of grazing-incidence X-ray diffraction (GIXD) using synchrotron radiation. Upon bulk doping of acceptor molecules into the homoepitaxial single crystals of rubrene, highly sensitive photoelectron yield spectroscopy (PYS) measurements unveiled a transition of the electronic states, from induction of hole states at the valence band maximum at an adequate doping ratio (10 ppm), to disturbance of the valence band itself for excessive ratios (≥ 1000 ppm), probably due to the lattice distortion.

X-ray diffraction patterns for BaR2PdO5 (R=Nd, Sm, Eu, and Gd)

1996 ◽  
Vol 11 (1) ◽  
pp. 9-12
Author(s):  
W. Wong-Ng
Keyword(s):  
Materials Characterization ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
The Eu

Calculated patterns for the BaR2PdO5 series, in which X is Pd and R=Nd, Sm, Eu, or Gd, have been prepared for materials characterization until experimental patterns can be determined. These compounds are isostructural to the superconductor related “brown phases” BaLa2CuO5 and BaNd2CuO5, which are tetragonal with space group P4/mbm, Z=4. The cell parameters of the Eu and Gd compounds were derived from the La and Nd analogs. The calculated patterns of these four compounds compared well to an experimental pattern of BaNd2CuO5.

Luminescent and magnetic bifunctional coordination complex based on a chiral tartaric acid derivative and europium

2019 ◽  
Vol 75 (9) ◽  
pp. 1220-1227 ◽  
Author(s):  
Mei-rong Han ◽  
Shao-dong Li ◽  
Ling Ma ◽  
Bang Yao ◽  
Si-Si Feng ◽  
...  
Keyword(s):  
Tartaric Acid ◽  
Complex I ◽  
Coupling Parameter ◽  
Chain Structure ◽  
Magnetic Behaviour ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Carboxylate Groups ◽  
The Eu

A new mononuclear europium complex incorporating the (+)-di-p-toluoyl-D-tartaric acid (D-H2DTTA) ligand, namely, catena-poly[tris{μ2-3-carboxy-2,3-bis[(4-methylphenyl)carbonyloxy]propanoato}tris(methanol)europium(III)], [Eu(C20H17O8)3(CH3OH)3] n , (I), has been synthesized and characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and single-crystal X-ray diffraction analysis. The structure analysis indicates that complex (I) crystallizes in the trigonal space group R3 and exhibits an infinite one-dimensional chain structure, in which the Eu3+ ion is surrounded by six O atoms from six D-HDTTA− ligands and three O atoms from three coordinated methanol molecules, thus forming a tricapped trigonal prism geometry. The D-H2DTTA ligand is partially deprotonated and adopts a μ1,6-coordination mode via two carboxylate groups to link adjacent Eu3+ ions, affording an infinite one-dimensional propeller-shaped coordination polymer chain along the c axis, with an Eu...Eu distance of 7.622 (1) Å. Moreover, C—H...π interactions lead to the formation of helical chains running along the c axis and the whole structure displays a snowflake pattern in the ab plane. The circular dichroism spectrum confirms the chirality of complex (I). The solid-state photoluminescence properties were also investigated at room temperature and (I) exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.63, 0.32), with a reasonably long lifetime of 0.394 ms, indicating effective energy transfer from the ligand to the metal centre. In addition, a magnetic investigation reveals single-ion magnetic behaviour. The spin-orbit coupling parameter (λ) between the ground and excited states is fitted to be 360 (2) cm−1 through Zeeman perturbation. Therefore, complex (I) may be regarded as a chiral optical-magneto bifunctional material.

scholarly journals Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72− in H2O

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5955
Author(s):  
Qi-Ying Weng ◽  
Ya-Li Zhao ◽  
Jia-Ming Li ◽  
Miao Ouyang
Keyword(s):  
Detection Limit ◽  
Aqueous Media ◽  
Three Dimensional ◽  
Cobalt Atom ◽  
High Sensitivity ◽  
X Ray Diffraction ◽  
Chlorobenzoic Acid ◽  
X Ray ◽  
Highly Sensitive ◽  
Hydrogen Bonded

A pair of cobalt(II)-based hydrogen-bonded organic frameworks (HOFs), [Co(pca)2(bmimb)]n (1) and [Co2(pca)4(bimb)2] (2), where Hpca = p-chlorobenzoic acid, bmimb = 1,3-bis((2-methylimidazol-1-yl)methyl)benzene, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 has a one-dimensional (1D) infinite chain network through the deprotonated pca− monodentate chelation and with a μ2-bmimb bridge Co(II) atom, and 2 is a binuclear Co(II) complex construction with a pair of symmetry-related pca− and bimb ligands. For both 1 and 2, each cobalt atom has four coordinated twisted tetrahedral configurations with a N2O2 donor set. Then, 1 and 2 are further extended into three-dimensional (3D) or two-dimensional (2D) hydrogen-bonded organic frameworks through C–H···Cl interactions. Topologically, HOFs 1 and 2 can be simplified as a 4-connected qtz topology with a Schläfli symbol {64·82} and a 4-connected sql topology with a Schläfli symbol {44·62}, respectively. The fluorescent sensing application of 1 was investigated; 1 exhibits high sensitivity recognition for Fe3+ (Ksv: 10970 M−1 and detection limit: 19 μM) and Cr2O72− (Ksv: 12960 M−1 and detection limit: 20 μM). This work provides a feasible detection platform of HOFs for highly sensitive discrimination of Fe3+ and Cr2O72− in aqueous media.

Magnetic and Optical Properties of Eu-doped GaN

2006 ◽  
Vol 955 ◽  
Author(s):  
Jennifer Hite ◽  
G T Thaler ◽  
J H Park ◽  
A J Steckl ◽  
C R Abernathy ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Room Temperature Ferromagnetism ◽  
Inverse Correlation ◽  
Absolute Intensity ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Cell Temperature ◽  
X Ray ◽  
Pl Intensity ◽  
The Eu

ABSTRACTGaN films were doped with Eu to a concentration of ∼0.12 at. % during growth at 800°C by molecular beam epitaxy, with the Eu cell temperature held constant at 470°C. All samples were post-annealed at 675°C. The films exhibited strong photoluminescence (PL) in the red (622 nm) whose absolute intensity was a function of the Ga flux during growth, which ranged from 3-5.4×10−7 Torr. The maximum PL intensity was obtained at a Ga flux of 3.6×10−7 Torr. The samples showed room temperature ferromagnetism with saturation magnetization of ∼0.1-0.45 emu/cm3, consistent with past reports where the Eu was found to be predominantly occupying substitutional Ga sites. There was an inverse correlation between the PL intensity and the saturation magnetization in the films. X-ray diffraction showed the presence of EuGa phases under all of our growth conditions but these cannot account for the observed magnetic properties.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

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