scholarly journals Solid-State Dispersions of Platinum in the SnO2 and Fe2O3 Nanomaterials

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3349
Author(s):  
Edi Radin ◽  
Goran Štefanić ◽  
Goran Dražić ◽  
Ivan Marić ◽  
Tanja Jurkin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid State ◽  
Crystal Lattice ◽  
Platinum Nanoparticles ◽  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Experimental Conditions ◽  
Oxide Supports ◽  
Sensing Applications

The dispersion of platinum (Pt) on metal oxide supports is important for catalytic and gas sensing applications. In this work, we used mechanochemical dispersion and compatible Fe(II) acetate, Sn(II) acetate and Pt(II) acetylacetonate powders to better disperse Pt in Fe2O3 and SnO2. The dispersion of platinum in SnO2 is significantly different from the dispersion of Pt over Fe2O3. Electron microscopy has shown that the elements Sn, O and Pt are homogeneously dispersed in α-SnO2 (cassiterite), indicating the formation of a (Pt,Sn)O2 solid solution. In contrast, platinum is dispersed in α-Fe2O3 (hematite) mainly in the form of isolated Pt nanoparticles despite the oxidative conditions during annealing. The size of the dispersed Pt nanoparticles over α-Fe2O3 can be controlled by changing the experimental conditions and is set to 2.2, 1.2 and 0.8 nm. The rather different Pt dispersion in α-SnO2 and α-Fe2O3 is due to the fact that Pt4+ can be stabilized in the α-SnO2 structure by replacing Sn4+ with Pt4+ in the crystal lattice, while the substitution of Fe3+ with Pt4+ is unfavorable and Pt4+ is mainly expelled from the lattice at the surface of α-Fe2O3 to form isolated platinum nanoparticles.

scholarly journals Gas Sensing Properties of NiSb2O6 Micro- and Nanoparticles in Propane and Carbon Monoxide Atmospheres

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Verónica-M. Rodríguez-Betancourtt ◽  
Héctor Guillén Bonilla ◽  
Martín Flores Martínez ◽  
Alex Guillén Bonilla ◽  
J. P. Moran Lazaro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Monoxide ◽  
Gas Sensing ◽  
Average Diameter ◽  
Cell Parameters ◽  
Sensing Applications ◽  
Transmission Electron ◽  
Colloidal Method ◽  
Antimony Chloride ◽  
20 Nm

Micro- and nanoparticles of NiSb2O6 were synthesized by the microwave-assisted colloidal method. Nickel nitrate, antimony chloride, ethylenediamine, and ethyl alcohol were used. The oxide was obtained at 600°C and was analyzed by X-ray diffraction (XRD) and Raman spectroscopy, showing a trirutile-type structure with cell parameters a = 4.641 Å, c = 9.223 Å, and a space group P42/mnm (136). Average crystal size was estimated at ~31.19 nm, according to the XRD-peaks. The microstructure was scrutinized by scanning electron microscopy (SEM), observing microrods measuring ~3.32 μm long and ~2.71 μm wide, and microspheres with an average diameter of ~8 μm; the size of the particles shaping the microspheres was measured in the range of ~0.22 to 1.8 μm. Transmission electron microscopy (TEM) revealed that nanoparticles were obtained with sizes in the range of 2 to 20 nm (~10.7 nm on average). Pellets made of oxide’s powders were tested in propane (C3H8) and carbon monoxide (CO) atmospheres at different concentrations and temperatures. The response of the material increased significantly as the temperature and the concentration of the test gases rose. These results show that NiSb2O6 may be a good candidate for gas sensing applications.

scholarly journals Synthesis of SnO2 nanowires forCO, CH4 and CH3OH gases sensing

2018 ◽  
Vol 14 (8) ◽  
pp. 155014771879075 ◽  
Author(s):  
Khurram Shehzad ◽  
Nazar Abbas Shah ◽  
Muhammad Amin ◽  
Murrawat Abbas ◽  
Waqar Adil Syed
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gas Sensing ◽  
Reduction Process ◽  
X Ray ◽  
Sensing Applications ◽  
Microscopy Investigation ◽  
Sno2 Nanowires ◽  
Visible Spectra ◽  
Scanning Electron

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.

Pt nanoparticles decorated SnO2 nanoneedles for efficient CO gas sensing applications

2018 ◽  
Vol 256 ◽  
pp. 656-664 ◽  
Author(s):  
Qu Zhou ◽  
Lingna Xu ◽  
Ahmad Umar ◽  
Weigen Chen ◽  
Rajesh Kumar
Keyword(s):  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Sensing Applications ◽  
Co Gas

scholarly journals Flame-Made Pt-Loaded TiO2Thin Films and Their Application as H2Gas Sensors

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Weerasak Chomkitichai ◽  
Hathaithip Ninsonthi ◽  
Chaikarn Liewhiran ◽  
Anurat Wisitsoraat ◽  
Saengrawee Sriwichai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Hydrogen Gas Sensors ◽  
Operating Temperatures ◽  
Xrd Patterns ◽  
Deposited Film

The hydrogen gas sensors were developed successfully using flame-made platinum-loaded titanium dioxide (Pt-loaded TiO2) nanoparticles as the sensing materials. Pt-loaded TiO2thin films were prepared by spin-coating technique onto Al2O3substrates interdigitated with Au electrodes. Structural and gas-sensing characteristics were examined by using scanning electron microscopy (SEM) and showed surface morphology of the deposited film. X-ray diffraction (XRD) patterns can be confirmed to be the anatase and rutile phases of TiO2. High-resolution transmission electron microscopy (HRTEM) showed that Pt nanoparticles deposited on larger TiO2nanoparticles. TiO2films loaded with Pt nanoparticles were used as conductometric sensors for the detection of H2. The gas sensing of H2was studied at the operating temperatures of 300, 350, and 400°C in dry air. It was found that 2.00 mol% Pt-loaded TiO2sensing films showed higher response towards H2gas than the unloaded film. In addition, the responses of Pt-loaded TiO2films at all operating temperatures were higher than that of unloaded TiO2film. The response increased and the response time decreased with increasing of H2concentrations.

Hydrogen and Ethanol Sensing Properties of Pd-Loaded ZnO Nanoparticles Synthesized by Flame Spray Pyrolysis

2015 ◽  
Vol 1131 ◽  
pp. 146-152 ◽  
Author(s):  
Chawarat Siriwong ◽  
Jintaporn Yimchoy ◽  
Sangtian Nabsanit ◽  
Anurat Wisitsoraat ◽  
Sukon Phanichphant
Keyword(s):  
Electron Microscopy ◽  
Spray Pyrolysis ◽  
Zno Nanoparticles ◽  
Gas Sensing ◽  
Flame Spray Pyrolysis ◽  
Flame Spray ◽  
Coating Film ◽  
Sensing Applications ◽  
Transmission Electron ◽  
Ethanol Sensing

Pure ZnO and Palladium (Pd)-loaded ZnO nanoparticles containing 0.25, 0.50, 0.75 and 1.0 mol% of Pd were successfully synthesized by flame spray pyrolysis (FSP) and characterized for hydrogen and ethanol sensing applications. The crystalline phase, morphology and size of these nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) in order to correlate physical properties with gas sensing performance. The sensing films were fabricated by coating nanoparticles with organic paste composed of terpineol and ethyl cellulose as a vehicle binder on Al2O3 substrate interdigitated with gold electrodes. The film thicknesses were varied by controlling the numbers of coating. Film morphologies of gas sensors were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Moreover, response time and sensitivity of these sensors towards hydrogen and ethanol were evaluated under operating temperatures ranging from 200 ̶ 350°C in dry air. Finally, The optimum amount of loading Pd and film thickness were investigated.

Analysis of Pt-Nanoparticles Embedded on Crystalline TiO2 Studied by Transmission Electron Microscopy

2000 ◽  
Vol 638 ◽  
Author(s):  
Jordi Arbiol ◽  
Ana Ruiz ◽  
Albert Cirera ◽  
Francisca Peiró ◽  
Albert Cornet ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Inductively Coupled Plasma ◽  
Surface Density ◽  
Reaction Rate ◽  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Inductively Coupled ◽  
Transmission Electron

AbstractIn this work, we studied the Pt particles embedded on crystalline TiO2 nanopowders. As it is well known, metal nanoparticles distributed on TiO2 surface can improve dramatically the reaction rate and selectivity of reaction in gas sensing. We prepared a wide set of TiO2 samples with different nominal Pt concentration. The aim of this study was to analyse the Pt distribution on TiO2 surface (density of Pt, particle size distribution, etc.), as well as the Pt phases existing in our samples. We used High Resolution Transmission Electron Microscopy (HRTEM) as a powerful tool to study Pt particles morphology. The HRTEM images were compared with computer simulations to confirm the results obtained. The chemical composition of the material has been also investigated by Inductively Coupled Plasma (ICP).

Rational Synthesis and Optimization of Multifunctional Solid-State Gas Sensors

2004 ◽  
Vol 828 ◽  
Author(s):  
Johannes Schwank ◽  
Ghenadii Korotcenkov
Keyword(s):  
Solid State ◽  
Gas Sensors ◽  
Active Sites ◽  
Gas Sensing ◽  
Heterogeneous Systems ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Long Time ◽  
Overall Performance ◽  
Scale Design

ABSTRACTA new approach is discussed for the rational synthesis and development of optimized multifunctional solid-state gas sensors. Multifunctionality—the incorporation of multiple types of reactivities into a material, such as acid and/or base functionalities, oxidation and/or reduction functionalities, etc.—isa requirement in many gas sensing applications. The front end of many gas sensors contains catalytic layers, so that optimization of catalysts and optimization of gas sensors can be carried out in a synergistic fashion.Multifunctionality presents unique challenges to rational catalyst and sensor systems development because the overall performance of the material is a convolution of the performance of the various subcomponents, and optimization of these individual subcomponents in isolation does not necessarily lead to optimal, or even acceptable, overall performance. A major obstacle to dealing with these difficulties is the inherent complexity of heterogeneous systems prepared by traditional approaches, which makes it difficult to unambiguously identify the compositions and morphologies of the local active sites and their interactions. Further complicating the problem is the requirement to function in environments that can vary on both short and long time scales. A key to understanding, controlling, and optimizing these materials is the ability to produce and study well-defined sensor materials with well-defined composition and morphology, with the flexibility to vary the composition easily without jeopardizing the structural uniformity.The development of new or improved materials for gas sensor applications requires a search for novel and innovative approaches to the nano-scale design of these materials. The use of the technology of surface modification by successive ionic layer deposition (SILD) method is such an innovative approach that will be discussed in this paper.

Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy

2019 ◽  
Vol 9 (14) ◽  
pp. 3743-3752 ◽  
Author(s):  
Vytautas Klimavicius ◽  
Sarah Neumann ◽  
Sebastian Kunz ◽  
Torsten Gutmann ◽  
Gerd Buntkowsky
Keyword(s):  
Solid State ◽  
Co Oxidation ◽  
Dynamic Nuclear Polarization ◽  
Platinum Nanoparticles ◽  
Solid State Nmr ◽  
Room Temperature ◽  
Nuclear Polarization ◽  
Pt Nanoparticles ◽  
Support Materials

A series of 1 and 2 nm sized platinum nanoparticles deposited on different support materials are investigated by solid-state NMR combined with dynamic nuclear polarization (DNP).

Oxidation and reduction processes of platinum nanoparticles observed at the atomic scale by environmental transmission electron microscopy

Nanoscale ◽  
2014 ◽  
Vol 6 (21) ◽  
pp. 13113-13118 ◽  
Author(s):  
Hideto Yoshida ◽  
Hiroki Omote ◽  
Seiji Takeda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Platinum Nanoparticles ◽  
Pt Nanoparticles ◽  
Surface Oxidation ◽  
Atomic Scale ◽  
Environmental Transmission ◽  
Reduction Processes ◽  
Transmission Electron ◽  
Environmental Transmission Electron Microscopy

Atomic layers of Pt oxides were gradually formed on the surface of Pt nanoparticles in O2 and the oxides were reduced to Pt promptly in both vacuum and gas including CO. H2O vapor suppressed the surface oxidation.

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