scholarly journals A Comparative Study of Fabricating IrOx Electrodes by High Temperature Carbonate Oxidation and Cyclic Thermal Oxidation and Quenching Process

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1202
Author(s):  
Feifei Huang ◽  
Qingrui Wang ◽  
Weipeng Wang ◽  
Jiangshun Wu ◽  
Shuqiang Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Layer Structure ◽  
Film Formation ◽  
Thermal Heating ◽  
Effective Response ◽  
X Ray ◽  
Quenching Process ◽  
Drift Behavior

IrOx electrodes were fabricated by cyclic thermal heating and water quenching (CHQ) process and high temperature carbonate oxidation (HCO), respectively. By examining the E-pH relationship, response rate, potential drift behavior of the fabricated electrodes, the electrodes prepared by CHQ process seemed to show better comprehensive performance. Characterization tests such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and electrochemical impedance spectroscopy (EIS) were used to characterize the fabricated IrOx electrodes and find out the reason for the better performance of the electrodes prepared by CHQ process. Morphology tests indicate that the CHQ electrode shows a multi-layer structure with more ion channels, which could provide larger surface area for the H+ response process. Furthermore, combining the XPS, Raman and EIS tests etc., more effective response composition, better crystal quality, and smaller response reaction resistance of surface IrOx film could account for the better performance of the CHQ-fabricated IrOx electrode. The film formation process, H+ response mechanism, as well as the response behavior difference between the two kinds of the electrodes are further elaborated.

Ternary Composite of Molybdenum Disulfide-Graphene Oxide-Polyaniline for Supercapacitor

2021 ◽  
Author(s):  
Ke Qu ◽  
Yuqi Bai ◽  
Miao Deng
Keyword(s):  
Graphene Oxide ◽  
Molybdenum Disulfide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Light Emitting Diode ◽  
Rate Capability ◽  
Energy Storage And Conversion ◽  
Carbon Paper ◽  
Power Sources ◽  
X Ray

Abstract The ever-increasing need for small and lightweight power sources for use in portable or wearable electronic devices has spurred the development of supercapacitors as a promising energy storage and conversion system. In this work, a simple, facile and easy-to-practice method has been developed to employ carbon paper (CP) as the support to coat molybdenum disulfide (MoS2) and graphene oxide (GO), followed by electrodeposition of polyaniline (PANI) to render CP/MoS2-GO-PANI. The preparation parameters, such as amounts of MoS2, GO and number of aniline electropolymerization cycles, have been optimized to render CP/MoS2-GO-PANI the best capacitive performance. The as-prepared optimal CP/MoS2-GO-PANI is characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The supercapacitive properties of CP/MoS2-GO-PANI as an electrode have been evaluated electrochemically via cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy testing. CP/MoS2-GO-PANI delivers a specific capacitance of 255.1 F/g at 1.0 A/g and exhibits excellent rate capability under larger current densities. Moreover, a symmetrical supercapacitor is assembled and three are connected in series to power a light-emitting diode for ~15 minutes, demonstrating the promising application potential of CP/MoS2-GO-PANI-based supercapacitor.

Xps Analysis of the Sapphire Surface as a Function of High Temperature Vacuum Annealing

1989 ◽  
Vol 159 ◽  
Author(s):  
E.D. Richmond
Keyword(s):  
High Temperature ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Vacuum Annealing ◽  
Xps Analysis ◽  
Chemical Changes ◽  
Cleaning Procedure ◽  
Sapphire Surface ◽  
X Ray ◽  
First Time

ABSTRACTFor the first time the (1102) surface of sapphire has been investigated by X-ray photoelectron spectroscopy to ascertain chemical changes resulting from annealing in vacuum at 1300° C and 1450° C. As received substrates had a substantial surface C contaminant. For substrates that were chemically cleaned before inserting them into the MBE system no trace of carbon is detected. A residual flourine contaminant results from the cleaning procedure and is desorbed by the vacuum annealing. Spectra of annealed substrates are compared to the unannealed chemically cleaned substrates. The annealed substrates exhibit 0.4 to 0.5 eV shift to higher binding energy of the Al peak and a 0.3 eV shift to higher binding energy of the O peak. In addition, a 2% depletion of oxygen from the surface occurs.

High Temperature Oxidation Behavior of SUS310S Austenitic Stainless Steel

2014 ◽  
Vol 941-944 ◽  
pp. 212-215
Author(s):  
Tao Zheng ◽  
Jing Tao Han
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Behavior ◽  
Layer Structure ◽  
Energy Dispersive Spectrometer ◽  
Austenitic Stainless Steels ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
High Oxidation Resistance ◽  
Ray Diffusion

The oxidation behavior of SUS310S austenitic stainless steels was studied in isothermal conditions at different temperatures between 800oC and 1100oC for 96h in air. The oxidation kinetics was analyzed, the surface and cross-section of the oxide scale grown by oxidation were characterized by using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffusion (XRD) and X-ray photoelectron spectroscopy (XPS). The SUS310S steel has high oxidation resistance at 800oC and with the increase of the temperature, the parabolic rate constants is constantly increasing. Examination of the morphology and composition of oxide layers reveals a double-layer structure, The inner layer is mainly chromium oxide (Cr2O3) and is covered by an uneven thinness outer layer of manganese-chromium or iron-chromium spinel oxide.

scholarly journals Organosilane-functionalization of nanostructured indium tin oxide films

2016 ◽  
Vol 6 (6) ◽  
pp. 20160056 ◽  
Author(s):  
R. Pruna ◽  
F. Palacio ◽  
M. Martínez ◽  
O. Blázquez ◽  
S. Hernández ◽  
...  
Keyword(s):  
Surface Area ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Annealing Treatment ◽  
Electrochemical Analysis ◽  
Cyclic Voltammograms ◽  
X Ray ◽  
Chip Technology ◽  
Significant Difference

Fabrication and organosilane-functionalization and characterization of nanostructured ITO electrodes are reported. Nanostructured ITO electrodes were obtained by electron beam evaporation, and a subsequent annealing treatment was selectively performed to modify their crystalline state. An increase in geometrical surface area in comparison with thin-film electrodes area was observed by atomic force microscopy, implying higher electroactive surface area for nanostructured ITO electrodes and thus higher detection levels. To investigate the increase in detectability, chemical organosilane-functionalization of nanostructured ITO electrodes was performed. The formation of 3-glycidoxypropyltrimethoxysilane (GOPTS) layers was detected by X-ray photoelectron spectroscopy. As an indirect method to confirm the presence of organosilane molecules on the ITO substrates, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were also carried out. Cyclic voltammograms of functionalized ITO electrodes presented lower reduction-oxidation peak currents compared with non-functionalized ITO electrodes. These results demonstrate the presence of the epoxysilane coating on the ITO surface. EIS showed that organosilane-functionalized electrodes present higher polarization resistance, acting as an electronic barrier for the electron transfer between the conductive solution and the ITO electrode. The results of these electrochemical measurements, together with the significant difference in the X-ray spectra between bare ITO and organosilane-functionalized ITO substrates, may point to a new exploitable oxide-based nanostructured material for biosensing applications. As a first step towards sensing, rapid functionalization of such substrates and their application to electrochemical analysis is tested in this work. Interestingly, oxide-based materials are highly integrable with the silicon chip technology, which would permit the easy adaptation of such sensors into lab-on-a-chip configurations, providing benefits such as reduced size and weight to facilitate on-chip integration, and leading to low-cost mass production of microanalysis systems.

scholarly journals Amorphous Ni x Co y P-supported TiO2 nanotube arrays as an efficient hydrogen evolution reaction electrocatalyst in acidic solution

2019 ◽  
Vol 10 ◽  
pp. 62-70 ◽  
Author(s):  
Yong Li ◽  
Peng Yang ◽  
Bin Wang ◽  
Zhongqing Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Nanotube Arrays ◽  
Active Surface Area ◽  
X Ray ◽  
Transmission Electron

Bimetallic phosphides have been attracting increasing attention due to their synergistic effect for improving the hydrogen evolution reaction as compared to monometallic phosphides. In this work, NiCoP modified hybrid electrodes were fabricated by a one-step electrodeposition process with TiO2 nanotube arrays (TNAs) as a carrier. X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy and scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy were used to characterize the physiochemical properties of the samples. The electrochemical performance was investigated by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. We show that after incorporating Co into Ni–P, the resulting Ni x Co y P/TNAs present enhanced electrocatalytic activity due to the improved electron transfer and increased electrochemically active surface area (ECSA). In 0.5 mol L−1 H2SO4 electrolyte, the Ni x Co y P/TNAs (x = 3.84, y = 0.78) demonstrated an ECSA value of 52.1 mF cm−2, which is 3.8 times that of Ni–P/TNAs (13.7 mF cm−2). In a two-electrode system with a Pt sheet as the anode, the Ni x Co y P/TNAs presented a bath voltage of 1.92 V at 100 mA cm−2, which is an improvment of 79% over that of 1.07 V at 10 mA cm−2.

Surface Analysis, Microstructural Characterization and Local Corrosion Processes in Decarburized SAE 9254 Spring Steel

CORROSION ◽  
10.5006/3234 ◽  
2019 ◽  
Vol 75 (12) ◽  
pp. 1474-1486
Author(s):  
Jéssica Cristina Costa de Castro Santana ◽  
Rejane Maria Pereira da Silva ◽  
Renato Altobelli Antunes ◽  
Sydney Ferreira Santos
Keyword(s):  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Microstructural Characterization ◽  
Spring Steel ◽  
Laser Scanning Microscopy ◽  
Local Corrosion ◽  
Confocal Laser ◽  
X Ray ◽  
Decarburized Layer

The aim of the present work was to study the surface chemistry, microstructure, and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 850°C and 900°C, and oil quenched. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by x-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization were used to assess the global corrosion behavior of the decarburized samples. Scanning electrochemical microscopy was used to evaluate the influence of decarburization on the local corrosion activity. Microstructural characterization and x-ray photoelectron spectroscopy analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and Si oxides in the decarburized layer.

scholarly journals Comparative Study of ZnO Thin Films Grown on Quartz Glass and Sapphire (001) Substrates by Means of Magnetron Sputtering and High-Temperature Annealing

2019 ◽  
Vol 9 (21) ◽  
pp. 4509
Author(s):  
Weijia Yang ◽  
Fengming Wang ◽  
Zeyi Guan ◽  
Pengyu He ◽  
Zhihao Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Magnetron Sputtering ◽  
Comparative Study ◽  
Quartz Glass ◽  
Photoelectron Spectroscopy ◽  
Zno Thin Films ◽  
High Temperature Annealing ◽  
X Ray ◽  
Glass Substrates

In this work, we reported a comparative study of ZnO thin films grown on quartz glass and sapphire (001) substrates through magnetron sputtering and high-temperature annealing. Firstly, the ZnO thin films were deposited on the quartz glass and sapphire (001) substrates in the same conditions by magnetron sputtering. Afterwards, the sputtered ZnO thin films underwent an annealing process at 600 °C for 1 h in an air atmosphere to improve the quality of the films. X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectra, photoluminescence spectra, and Raman spectra were used to investigate the structural, morphological, electrical, and optical properties of the both as-received ZnO thin films. The ZnO thin films grown on the quartz glass substrates possess a full width of half maximum value of 0.271° for the (002) plane, a surface root mean square value of 0.50 nm and O vacancies/defects of 4.40% in the total XPS O 1s peak. The comparative investigation reveals that the whole properties of the ZnO thin films grown on the quartz glass substrates are comparable to those grown on the sapphire (001) substrates. Consequently, ZnO thin films with high quality grown on the quartz glass substrates can be achieved by means of magnetron sputtering and high-temperature annealing at 600 °C.

Sub-nm-Scale Depth Profiling of Nitrogen in NO- and N2-Annealed SiO2/4H-SiC(0001) Structures

2019 ◽  
Vol 963 ◽  
pp. 226-229
Author(s):  
Kidist Moges ◽  
Mitsuru Sometani ◽  
Takuji Hosoi ◽  
Takayoshi Shimura ◽  
Shinsuke Harada ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
High Temperature ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Annealing Duration ◽  
Nanometer Scale ◽  
Pure Nitrogen ◽  
X Ray ◽  
Initial Stage

We demonstrated an x-ray photoelectron spectroscopy (XPS)-based technique to reveal the detailed nitrogen profile in nitrided SiO2/4H-SiC structures with sub-nanometer-scale-resolution. In this work, nitric oxide (NO)- and pure nitrogen (N2)-annealed SiO2/4H-SiC(0001) structures were characterized. The measured results of NO-annealed samples with various annealing duration indicate that preferential nitridation just at the SiO2/SiC interfaces (~0.3 nm) proceeds in the initial stage of NO annealing and a longer duration leads to the distribution of nitrogen in the bulk SiO2 within few nanometers of the interface. The high-temperature N2 annealing was found to induce not only SiO2/SiC interface nitridation similarly to NO annealing but also SiO2 surface nitridation.

Influence of nitrite on chemical composition of passivation film of steel bars under the coupling effects of carbonization and chloride

2019 ◽  
Vol 66 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Junzhe Liu ◽  
Jundi Geng ◽  
Hui Wang ◽  
Mingfang Ba ◽  
Zhiming He
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Chloride Solution ◽  
Layer Structure ◽  
Coupling Effects ◽  
Content Type ◽  
X Ray ◽  
Passivation Film ◽  
Steel Bars ◽  
Micro Structures

Purpose This paper aims to study the influence of NaNO2 on the chemical composition of passivation film. Design/methodology/approach X-ray photoelectron spectroscopy and X-ray diffraction were selected to determine the composition of passivation film of steel bars in mortar. The specimens were exposed to the chloride solution, carbonation environment and the coupling effects of chloride solution and carbonation. The chemical composition and micro structures at 0 and 5 nm from the outer surface of the passivation film of steel bars were analyzed. Findings Results showed that the nitrite inhibitor improved the forming rate of the passivation film and increased the mass ratio of Fe3O4 to FeOOH on the surface of steel bars. The component of Fe3O4 at 5 nm of the steel passivation film was more than that at 0 nm. Sodium ferrite in the pore solution was easily hydrolyzed and then FeOOH was formed. Therefore, due to the nitrite inhibitor, a “double layer structure” of the passivation film was formed to prevent steels bars from corrosion. Originality/value This is original work and may help the researchers further understand the mechanism of rust resistance by nitrite inhibitor.

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