scholarly journals Modification of Cobalt Oxide Electrochemically Deposited on Stainless Steel Meshes with Co-Mn Thin Films Prepared by Magnetron Sputtering: Effect of Preparation Method and Application to Ethanol Oxidation

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1453
Author(s):  
Květa Jirátová ◽  
Roman Perekrestov ◽  
Michaela Dvořáková ◽  
Jana Balabánová ◽  
Martin Koštejn ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Catalytic Activity ◽  
Magnetron Sputtering ◽  
Cobalt Oxide ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
Deep Oxidation ◽  
Active Components ◽  
Total Oxidation ◽  
X Ray

Magnetron sputtering is an advantageous method for preparing catalysts supported on stainless steel meshes. Such catalysts are particularly suitable for processes carried out at high space velocities. One of these is the catalytic total oxidation of volatile organic compounds (VOC), economically feasible and environmentally friendly method of VOC abatement. The reactive radio frequency (RF) magnetron sputtering of Mn and Co + Mn mixtures in an oxidation Ar + O2 atmosphere was applied to form additional thin oxide coatings on cobalt oxide layers prepared by electrochemical deposition and heating on stainless steel meshes. Time of the RF magnetron sputtering was changed to obtain MnOx and CoMnOx coatings of various thickness (0.1–0.3 µm). The properties of the supported CoOx–MnOx and CoOx–CoMnOx catalysts were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), temperature programmed reduction (H2-TPR), Fourier-transform infrared (FTIR) and Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The catalytic activity was investigated in the deep oxidation of ethanol, which was employed as a model VOC. According to the specific activities (amount of ethanol converted per unit mass of metal oxides per hour), the performance of CoOx–MnOx catalysts was higher than that of CoOx–CoMnOx ones. The catalysts with the smallest layer thickness (0.1 µm) showed the highest catalytic activity. Compared to the commercial pelletized Co–Mn–Al mixed oxide catalyst, the sputtered catalysts exhibited considerably higher (23–87 times) catalytic activity despite the more than 360–570 times lower content of the Co and Mn active components in the catalytic bed.

scholarly journals Cobalt Oxide Catalysts in the Form of Thin Films Prepared by Magnetron Sputtering on Stainless-Steel Meshes: Performance in Ethanol Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 806 ◽  
Author(s):  
Květa Jirátová ◽  
Roman Perekrestov ◽  
Michaela Dvořáková ◽  
Jana Balabánová ◽  
Pavel Topka ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Catalytic Activity ◽  
Magnetron Sputtering ◽  
Specific Activity ◽  
Deep Oxidation ◽  
Unit Weight ◽  
Active Components ◽  
Total Oxidation ◽  
Industrial Gases ◽  
Temperature Programmed

Catalytic total oxidation is an effective procedure to minimize emissions of volatile organic compounds (VOC) emissions in industrial gases. Catalysts in the form of meshes are remarkable as they minimize the internal diffusion of reactants during the reaction as well as the need of expensive active components. In this paper, various conditions of radio frequency magnetron sputtering of cobalt on stainless-steel meshes was applied during catalyst preparation. Properties of the supported Co3O4 catalysts were characterized by SEM, XRD, temperature programmed reduction (H2-TPR), FTIR, XPS, and Raman spectroscopy. Catalytic activity was examined in deep oxidation of ethanol chosen as a model VOC. Performance of the catalysts depended on the amount of Co3O4 deposited on the supporting meshes. According to specific activities (the amounts of ethanol converted per unit weight of Co3O4), smaller Co3O4 particle size led to increased catalytic activity. The catalyst prepared by sputtering in an Ar+O2 atmosphere without calcination showed the highest catalytic activity, which decreased after calcination due to enlargement of Co3O4 particles. However, specific activity of this catalyst was more than 20 times higher than that of pelletized commercial Co3O4 catalyst used for comparison.

The piezoresistive properties research of SiC thin films prepared by RF magnetron sputtering

2019 ◽  
Vol 33 (15) ◽  
pp. 1950152 ◽  
Author(s):  
Jing Wu ◽  
Xiaofeng Zhao ◽  
Chunpeng Ai ◽  
Zhipeng Yu ◽  
Dianzhong Wen
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Cantilever Beam ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Rf Magnetron Sputtering ◽  
Micro Electro Mechanical System ◽  
Gauge Factor ◽  
X Ray ◽  
Sputtering Power

To research the piezoresistive properties of SiC thin films, a testing structure consisting of a cantilever beam, SiC thin films piezoresistors and a Cr/Pt electrode is proposed in this paper. The chips of testing structure were fabricated by micro-electro-mechanical system (MEMS) technology on a silicon wafer with [Formula: see text]100[Formula: see text] orientation, in which SiC thin films were deposited by using radio-frequency (13.56 MHz) magnetron sputtering method. The effect of sputtering power, annealing temperature and time on the microstructure and morphology of the SiC thin films were investigated by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). It indicates that a good continuity and uniform particles on the SiC thin film surface can be achieved at sputtering power of 160 W after annealing. To verify the existence of Si–C bonds in the thin films, X-ray photoelectron spectroscopy (XPS) was used. Meanwhile, the piezoresistive properties of SiC thin films piezoresistors were measured using the proposed cantilever beam. The test result shows that it is possible to achieve a gauge factor of 35.1.

Application of V2O5 in Thin Film Microbatteries Prepared by RF Magnetron Sputtering

2009 ◽  
Vol 79-82 ◽  
pp. 931-934 ◽  
Author(s):  
Liang Tang Zhang ◽  
Jie Song ◽  
Quan Feng Dong ◽  
Sun Tao Wu
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Unit Area ◽  
Rf Magnetron Sputtering ◽  
Micro Electro Mechanical System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mems Technology ◽  
Surface Morphologies ◽  
Sputtering System

The polycrystalline V2O5 films as the anode in V2O5 /LiPON /LiCoO2 lithium microbattary were prepared by RF magnetron sputtering system. The V2O5 films’ crystal structures, surface morphologies and composition were characterized and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The microbatteries were fabricated by micro electro-mechanical system (MEMS) technology. The battery active unit area is 500μm×500μm, and the thickness of V2O5, LiPON and LiCoO2 films was estimated to be 200, 610, and 220nm, respectively. The discharge volumetric capacity is between 9.36μAhcm-2μm-1 and 9.63μAhcm-2μm-1 after 40 cycles.

Synthesis and Characterization of Nb-Doped TiO2 Thin Films Prepared by RF Magnetron Sputtering

2015 ◽  
Vol 1117 ◽  
pp. 139-142 ◽  
Author(s):  
Marius Dobromir ◽  
Radu Paul Apetrei ◽  
A.V. Rogachev ◽  
Dmitry L. Kovalenko ◽  
Dumitru Luca
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Diffraction Patterns

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.

scholarly journals Synthesis, Microstructural, and Mechano-Tribological Properties of Self-Lubricating W-S-C(H) Thin Films Deposited by Different RF Magnetron Sputtering Procedures

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 272 ◽  
Author(s):  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Manuel Evaristo ◽  
Albano Cavaleiro
Keyword(s):  
Raman Spectroscopy ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
Ambient Air ◽  
Transition Metal Dichalcogenide ◽  
Clear Indication ◽  
X Ray ◽  
Operating Environments ◽  
Reactive Mode

Carbon-alloyed transition metal dichalcogenide (TMD) coatings have great potential for providing a good tribological response in diverse operating environments. There are different ways to synthesize these coatings by magnetron sputtering, with no clear indication of the best possible route for potential upscaling. In this study, tungsten-sulfur-carbon (W-S-C) coatings were deposited by radio frequency (RF) magnetron sputtering via four different methods. All coatings were sub-stoichiometric in terms of the S/W ratio, with the bombardment of the growing film with backscattered Ar neutrals being the main mechanism governing the S/W ratio. The crystallinity of the films was dependent on the C and S contents. X-ray photoelectron spectroscopy (XPS) revealed W-S and W-C bonding in all coatings. Raman spectroscopy showed the presence of an a-C phase with predominant sp2 bonding. The hardness of the coatings may be related to the C content and the S/W ratio. A friction coefficient of 0.06–0.08 was achieved during sliding in ambient air by the coatings deposited in non-reactive mode with optimal C contents. The results indicate that sputtering in non-reactive mode should be the method of choice for synthesis of these coatings.

scholarly journals Lanthanum based high surface area perovskite-type oxide and application in CO and propane combustion

2018 ◽  
Vol 34 (1) ◽  
pp. 31
Author(s):  
Paulo Roberto Nagipe Da Silva ◽  
Ana Brígida Soares
Keyword(s):  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Perovskite Phase ◽  
High Surface ◽  
High Surface Area ◽  
Propane Combustion ◽  
Total Oxidation ◽  
X Ray ◽  
Co Precipitation ◽  
Perovskite Type

The perovskite-type oxides using transition metals present a promising potential as catalysts in total oxidation reaction. The present work investigates the effect of synthesis by oxidant co-precipitation on the catalytic activity of perovskite-type oxides LaBO3 (B= Co, Ni, Mn) in total oxidation of propane and CO. The perovskite-type oxides were characterized by means of X-ray diffraction, nitrogen adsorption (BET method), thermo gravimetric and differential thermal analysis (ATG-DTA) and X-ray photoelectron spectroscopy (XPS). Through a method involving the oxidant co-precipitation it’s possible to obtain catalysts with different BET surface areas, of 33-44 m2/g, according the salts of metal used. The characterization results proved that catalysts have a perovskite phase as well as lanthanum oxide, except LaMnO3, that presents a cationic vacancies and generation for known oxygen excess. The results of catalytic test showed that all oxides have a specific catalytic activity for total oxidation of CO and propane even though the temperatures for total conversion change for each transition metal and substance to be oxidized.

scholarly journals Eco-Friendly Cavity-Containing Iron Oxides Prepared by Mild Routes as Very Efficient Catalysts for the Total Oxidation of VOCs

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1387 ◽  
Author(s):  
Rut Sanchis ◽  
Daniel Alonso-Domínguez ◽  
Ana Dejoz ◽  
María Pico ◽  
Inmaculada Álvarez-Serrano ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Iron Oxides ◽  
Photoelectron Spectroscopy ◽  
Specific Activity ◽  
High Surface ◽  
Superior Performance ◽  
Porous Iron ◽  
Total Oxidation ◽  
X Ray

Iron oxides (FeOx) are non-toxic, non-expensive and environmentally friendly compounds, which makes them good candidates for many industrial applications, among them catalysis. In the present article five catalysts based on FeOx were synthesized by mild routes: hydrothermal in subcritical and supercritical conditions (Fe-HT, Few200, Few450) and solvothermal (Fe-ST1 and Fe-ST2). The catalytic activity of these catalysts was studied for the total oxidation of toluene using very demanding conditions with high space velocities and including water and CO2 in the feed. The samples were characterized by X-ray diffraction (XRD), scanning and high-resolution transmission electron microscopy (SEM and HRTEM), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption isotherms. It was observed that the most active catalyst was a cavity-containing porous sample prepared by a solvothermal method with a relatively high surface area (55 m2 g−1) and constituted by flower-like aggregates with open cavities at the catalyst surface. This catalyst displayed superior performance (100% of toluene conversion at 325 °C using highly demanding conditions) and this performance can be maintained for several catalytic cycles. Interestingly, the porous iron oxides present not only a higher catalytic activity than the non-porous but also a higher specific activity per surface area. The high activity of this catalyst has been related to the possible synergistic effect of compositional, structural and microstructural features emphasizing the role of the surface area, the crystalline phase present, and the properties of the surface.

Properties of Indium Tin Oxide Films Prepared by RF Magnetron Sputtering at Different Substrate Temperatures

2012 ◽  
Vol 502 ◽  
pp. 77-81
Author(s):  
Z.Y. Zhong ◽  
J.H. Gu ◽  
X. He ◽  
C.Y. Yang ◽  
J. Hou
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Rf Magnetron Sputtering ◽  
X Ray ◽  
Ito Thin Films

Indium tin oxide (ITO) thin films were deposited by RF magnetron sputtering on glass substrates employing a sintered ceramic target. The influence of substrate temperature on the structural, compositional, optical and electrical properties of the thin films were investigated by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), spectrophotometer and four-point probes. All the ITO thin films show a polycrystalline indium oxide structure and have a preferred orientation along the (222) direction. The substrate temperature significantly affects the crystal structure and optoelectrical properties of the thin films. With the increment of substrate temperature, the electrical resistivity of the deposited films decreases, the crystallite dimension, optical bandgap and average transmittance in the visible region increase. The ITO thin film deposited at substrate temperature of 200 °C possesses the best synthetic optoelectrical properties, with the highest transmittance, the lowest resistivity and the highest figure of merit.

The Influence of O2/Ar on the Dielectric Properties of Bismuth Zinc Niobate Titanium Thin Films Prepared by RF Magnetron Sputtering

2012 ◽  
Vol 252 ◽  
pp. 202-206
Author(s):  
Xiao Hua Sun ◽  
Zhi Meng Luo ◽  
Shuang Hou ◽  
Cai Hua Huang ◽  
Jun Zou
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
X Ray ◽  
Si Substrates ◽  
Low Dielectric ◽  
Metal Insulator Metal ◽  
Titanium Thin Films

BZNT (Bi1.5Zn0.5Nb0.5Ti1.5O7) thin films were prepared on Pt/Ti/SiO2/Si substrates by radio frequency (RF) magnetron sputtering in different O2/Ar ranging from 4:16 to 7:13. The structure and surface morphology of BZNT thin films were investigated by x-ray diffraction (XRD) and atom force microscopy (AFM). The analysis of component in BZNT films were carried out by x-ray photoelectron spectroscopy (XPS). The dielectric measurements were conducted on metal-insulator-metal capacitors at the frequency from 100 Hz to 1M Hz. It’s found that the O2/Ar ratios significantly influence the elements content in BZNT thin films and the morphology and dielectric properties of BZNT thin films. At 1M Hz, the dielectric constant of BZNT thin films deposited at O2/Ar ranging from 4:16 to 7:13 is 212, 187, 171, 196, respectively. The BZNT thin film prepared at O2/Ar = 6:14 shows the highest figure of merit for its very low dielectric loss of 0.0024.

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