scholarly journals Perspectives for usage of adsorption semiconductor sensors based on Pd/SnO2 in environmental monitoring of carbon monoxide and methane emission

2021 ◽  
Vol 280 ◽  
pp. 06003
Author(s):  
Lyudmila Oleksenko ◽  
George Fedorenko ◽  
Igor Matushko ◽  
Nelly Maksymovych ◽  
Inna Vasylenko
Keyword(s):  
Carbon Monoxide ◽  
Oxidation Reaction ◽  
Catalytic Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Semiconductor Sensor ◽  
Highly Sensitive ◽  
Semiconductor Sensors ◽  
Sensor Materials

Nanosized semiconductor sensor materials based on SnO2 with different palladium contents were obtained via zol-gel technology with the use of ethylene glycol and hydrate of tin (VI) chloride as precursors. Morphology and phase composition of nanosized sensor materials were studied by X-ray diffraction and TEM methods. Catalytic activities of the Pd/SnO2 nanomaterials in the reaction of H2 and CO oxidation were investigated. Adsorption semiconductor sensors based on Pd/SnO2 nanomaterials were made by their calcination up to 620 0C in air and the sensors were found to be highly sensitive to presence of CO and CH4 in air ambient. Higher responses to CO of Pd-containing sensors in comparison with their responses to CH4 were confirmed by higher reaction activity of CO in catalytic oxidation reaction. Differences in sensitive properties of the sensors to methane and carbon monoxide were explained by features of the catalytic reactions of methane and carbon monoxide oxidation occurring on surfaces of the gas sensitive layers of the sensors.

Photocatalytic activity of TiO2 synthesized by anodization and anodic spark deposition

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Characteristics ◽  
Amorphous Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Anodic Spark Oxidation ◽  
Porous Surfaces ◽  
Scanning Electron

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.

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.

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.

scholarly journals The use of resonant X-ray diffraction to tune destructive interference as a highly sensitive probe for structural distortions

2015 ◽  
Vol 71 (a1) ◽  
pp. s170-s170
Author(s):  
Carsten Richter ◽  
Erik Mehner ◽  
Melanie Nentwich ◽  
Juliane Hanzig ◽  
Matthias Zschornak ◽  
...  
Keyword(s):  
Destructive Interference ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Distortions ◽  
Highly Sensitive

scholarly journals A series of Mn(i) photo-activated carbon monoxide-releasing molecules with benzimidazole coligands: synthesis, structural characterization, CO releasing properties and biological activity evaluation

RSC Advances ◽  
2019 ◽  
Vol 9 (36) ◽  
pp. 20505-20512 ◽  
Author(s):  
Mixia Hu ◽  
YaLi Yan ◽  
Baohua Zhu ◽  
Fei Chang ◽  
Shiyong Yu ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Biological Activity ◽  
Activated Carbon ◽  
Fluorescence Spectroscopy ◽  
Single Crystal ◽  
Structural Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
C Nmr

Five Mn(i) photo-activated carbon monoxide-releasing molecules were synthesized by reactions of MnBr(CO)5 with L1–L4, and characterized via single crystal X-ray diffraction, 1H-NMR, 13C-NMR, IR, UV-vis and fluorescence spectroscopy.

scholarly journals Solvent-Tuned Synthesis of Mesoporous Nickel Cobaltite Nanostructures and Their Catalytic Properties

2019 ◽  
Vol 9 (6) ◽  
pp. 1100 ◽  
Author(s):  
Xiangfeng Guan ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Xiaoyan Li ◽  
Dagui Chen
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Nickel Cobaltite ◽  
Solvent Type ◽  
Bet Method ◽  
Mesoporous Nico2o4

In this paper, we prepared mesoporous nickel cobaltite (NiCo2O4) nanostructures with multi-morphologies by simple solvothermal and subsequent heat treatment. By adjusting the solvent type, mesoporous NiCo2O4 nanoparticles, nanorods, nanowires, and microspheres were easily prepared. The as-prepared products were systematically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) method. Furthermore, the catalytic activities towards the thermal decomposition of ammonium perchlorate (AP) of as-prepared NiCo2O4 nanostructures were investigated.

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.

CuO Nanostructure by Oxidization of Copper Thin Films

2008 ◽  
Vol 55-57 ◽  
pp. 645-648
Author(s):  
Phathaitep Raksa ◽  
A. Gardchareon ◽  
N. Mangkorntong ◽  
Supab Choopun
Keyword(s):  
Thin Films ◽  
Oxidation Reaction ◽  
Dye Sensitized Solar Cells ◽  
X Ray Diffraction ◽  
Copper Thin Film ◽  
X Ray ◽  
Sem Image ◽  
Dye Sensitized ◽  
Cuo Nanostructure ◽  
Sensitized Solar Cells

CuO nanostructures were synthesized by oxidizing copper thin films. The copper thin film was grown on alumina substrates by evaporation copper powder at pressure of 0.04 mtorr. The copper thin films were then oxidized 800, and 900oC for 12, 24 and 48 hr, respectively. The obtained CuO nanostructures were investigated by Energy Dispersive Spectroscopy (EDS), Field Emission Scanning Electron Microscope (FE-SEM) image, and X-Ray Diffraction (XRD). The diameter of CuO nanostructure is around 100-600 nanometers and it is depends on oxidation reaction time and temperature. These CuO nanostructures have a potential application for nanodevices such as nano gas sensor or dye-sensitized solar cells.

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