scholarly journals Gas sensing response of metal oxide layers based on Cox Oy with lithium ions

2020 ◽  
pp. 119-122
Author(s):  
Yu. A. Stenkin ◽  
◽  
D. V. Sokolov ◽  
K. E. Ivlev ◽  
◽  
...  

The gas response of layers based on lithium-doped cobalt oxides with different Li2 O/Cox Oy ratios is investigated. The synthesis conditions of oxide composites and the structural analysis of the obtained layers by scanning electron microscopy are presented. It is found that composites with the ratio of the initial components 1:1 have selectivity to formaldehyde, and with the ratio 3:2 — to nitrogen dioxide

IUCrJ ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Cristian-R. Boruntea ◽  
Peter N. R. Vennestrøm ◽  
Lars F. Lundegaard

During screening of the phase space using KOH and 1-methyl-4-aza-1-azoniabicyclo[2.2.2]octane hydroxide (1-methyl-DABCO) under hydrothermal zeolite synthesis conditions, K-paracelsian was synthesized. Scanning electron microscopy, energy dispersive X-ray spectroscopy and ex situ powder X-ray diffraction analysis revealed a material that is compositionally closely related to the mineral microcline and structurally closely related to the mineral paracelsian, both of which are feldspars. In contrast to the feldspars, K-paracelsian contains intrazeolitic water corresponding to one molecule per cage. In the case of K-paracelsian it might be useful to consider it a link between feldspars and zeolites. It was also shown that K-paracelsian can be described as the simplest endmember of a family of dense double-crankshaft zeolite topologies. By applying the identified building principle, a number of known zeolite topologies can be constructed. Furthermore, it facilitates the construction of a range of hypothetical small-pore structures that are crystallo-chemically healthy, but which have not yet been realized experimentally.


2018 ◽  
Vol 14 (8) ◽  
pp. 155014771879075 ◽  
Author(s):  
Khurram Shehzad ◽  
Nazar Abbas Shah ◽  
Muhammad Amin ◽  
Murrawat Abbas ◽  
Waqar Adil Syed

Synthesis of one-dimensional nanostructures, such as nanowires, is of vigorous significance for achieving the desired properties and fabricating functional devices. In this work, we report the synthesis of tin oxide (SnO2) nanowires on gold-catalyzed silicon substrate by carbothermal reduction process. SnO2 nanowires were synthesized with SnO2 and graphite powders as the source materials at atmospheric pressure and temperature of 900°C in the ambience of nitrogen (N2) gas. First, the effect of source material ratio SnO2:C on growth of SnO2 nanowires was studied. The structural, morphological and compositional properties of the samples were investigated by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The scanning electron microscopy investigation reveals that uniform dense nanowires of SnO2 (diameter ~127 nm and length ~40 µm) were synthesized with vapour–liquid–solid mechanism. Ultraviolet–visible spectra estimate that the optical band gap of the synthesized SnO2 nanowires was 3.72 eV. Second, the gas sensing performance of synthesized SnO2 nanowires was investigated by testing with carbon monoxide (CO), Methane (CH4) and methanol (CH3OH) gases at different operating temperatures and concentrations. Results indicate that the synthesized SnO2 nanowires are highly promising for gas sensing applications.


2008 ◽  
Vol 47-50 ◽  
pp. 363-366 ◽  
Author(s):  
Guang Zhu ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Mao Fa Wang ◽  
Yi Su

A simple combustion technique is presented for the preparation of mono-sized silica nanoparticles by employing tetraethyl orthosilicates as precursor. The as-grown white powders were characterized by means of scanning electron microscopy. The results showed the size of silica nanoparticles were relative to the unique synthesis conditions. According to the observation and analysis of the scanning electron microscopy images, the possible growth mechanism of silica nanoparticles in this process is proposed.


2019 ◽  
Vol 946 ◽  
pp. 235-241 ◽  
Author(s):  
D.I. Tishkevich ◽  
A.I. Vorobjova ◽  
D.A. Vinnik

Through-pores alumina membranes of 50 μm thickness and 70 × 70 mm size have been fabricated to deposit Ni nanowires by electrochemical processing. Due to highly ordered microstructure of the membranes, the pores were filled by nanowires almost to 100%. The membrane nanowires composite morphology; structure and chemical features have been studied by scanning electron microscopy, atomic-force microscopy and X-ray structural analysis. To measure the specific magnetization σ as a function of temperature in the range of 77–1400 K, the pondero-motive method was used.


2012 ◽  
Author(s):  
Rashidah Arsat ◽  
Mahyuddin Arsat ◽  
Michael Breedon ◽  
Kourosh Kalantar Zadeh ◽  
Wojtek Wlodarski

Dalam kertas kerja ini, struktur dan prestasi pengesanan gas oleh polianilin yang berskala nano yang dimendap di atas transduser lithium tantalate. Polimer berkonduksi ini disintesiskan melalui teknik electropolymerization. Struktur permukaan polianilin dicirikan dengan menggunakan Mikroskop Pengesan Elektron (Scanning Electron Microscopy). Didapati bahawa polianiline yang terhasil dipermukaan transducer adalah 3–dimensi struktur dan poros. Pengesan ini kemudian disiasat prestasinya terhadap konsentrasi gas yang berbeza dan berada dalam keadaan suhu bilik. Kata kunci: Pengesan H2; polianilin, berskala nano; electropolymerization; dop dan nyah–dop In this work, the structural and gas sensing properties of polyaniline nanostructures deposited on 36° lithium tantalite (LiTaO3) conductometric transducers was investigated. The polyaniline nanostructures were synthesized via an electropolymerization method. The morphology of the nanostructured polyaniline was characterized using Scanning Electron Microscopy (SEM). It was observed that the electropolymerised film was a three–dimensional (3D) porous structure of polyaniline fibers and nanotips. The conductometric sensors were exposed to different concentrations of hydrogen (H2) gas at room temperature. Key words: H2 sensor; polyaniline; nanostructures; electropolymerization; doped and dedoped


2019 ◽  
Vol 61 (11) ◽  
pp. 2240
Author(s):  
Ю.А. Стенькин ◽  
В.В. Болотов ◽  
Д.В. Соколов ◽  
В.Е. Росликов ◽  
К.Е. Ивлев

Nanocomposites based on multiwalled carbon nanotubes (MWCNT) with manganese dioxide (MnO2-x) and copper oxide (CuO) were obtained and investigated. The morphology and elemental composition of MWCNT-layer and nanocomposites MWCNT/MnO2-х, MWCNT/MnO2-х/CuO were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing response of MWCNT-layer and nanocomposites upon exposure to hydrogen sulfide (H2S) and nitrogen dioxide (NO2) was demonstrated at room temperature. Effect of increasing the conductivity of MWCNT-layer and nanocomposites upon exposure to NO2 indicates these nanomaterials have conductive of p-type. Copper oxide in nanocomposite significantly enhances the gas sensing response to H2S.


Sign in / Sign up

Export Citation Format

Share Document