scholarly journals Fabrication and Characterization of Iridium Oxide pH Microelectrodes Based on Sputter Deposition Method

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4996
Author(s):  
Ye Xi ◽  
Zhejun Guo ◽  
Longchun Wang ◽  
Qingda Xu ◽  
Tao Ruan ◽  
...  

pH value plays an important role in many fields such as chemistry and biology; therefore, rapid and accurate pH measurement is very important. Because of its advantages in preparation, wide test range, rapid response, and good biocompatibility, iridium oxide material has received more and more attention. In this paper, we present a method for preparing iridium oxide pH microelectrodes based on the sputter deposition method. The sputtering parameters of iridium oxide are also studied and optimized. Open-circuit potential tests show that microelectrodes exhibit near-Nernstian pH response with good linearity (about 60 mV/pH), fast response, high stability (a slight periodic fluctuation of potential change <2.5 mV in 24 h), and good reversibility in the pH range of 1.00–13.00.

1970 ◽  
Vol 25 ◽  
pp. 75-82
Author(s):  
Basu Ram Aryal ◽  
Jagadeesh Bhattarai

The synergistic effect of the simultaneous additions of tungsten and zirconium in thesputter-deposited amorphous or nanocrystalline Zr-(12-21)Cr-W alloys is studied in 0.5 MNaCl solution open to air at 25°C using corrosion tests and open circuit potentialmeasurements. Corrosion rates of the sputter-deposited Zr-(12-21)Cr-W alloys containing10-80 at % tungsten (that is, 0.95-1.85 x 10-2 mm.y-1) are more than one order of magnitudelower than that of the sputter-deposited tungsten and even lower than those of zirconium aswell as chromium in 0.5 M NaCl solution. The addition of 8-73 at % zirconium content inthe sputter-deposited binary W-(12-21)Cr alloys seems to be more effective to improve thecorrosion-resistant properties of the sputter-deposited ternary Zr-Cr-W alloys containing12-21 at % chromium in 0.5 M NaCl solution. The sputter-deposited Zr-(17-21)Cr-W alloyscontaining an adequate amounts of zirconium metal showed the more stable passivity andshowed higher corrosion resistance than those of alloy-constituting elements in 0.5 M NaClsolution open to air at 25°C.Keywords: Zr-(12-21)Cr-W alloys, sputter deposition, corrosion test, open circuit potential,0.5 M NaCl.DOI:  10.3126/jncs.v25i0.3305Journal of Nepal Chemical Society Volume 25, 2010 pp 75-82


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhuang Hui ◽  
Ming Xiao ◽  
Daozhi Shen ◽  
Jiayun Feng ◽  
Peng Peng ◽  
...  

Abstract With the increase in the use of electronic devices in many different environments, a need has arisen for an easily implemented method for the rapid, sensitive detection of liquids in the vicinity of electronic components. In this work, a high-performance power generator that combines carbon nanoparticles and TiO2 nanowires has been fabricated by sequential electrophoretic deposition (EPD). The open-circuit voltage and short-circuit current of a single generator are found to exceed 0.7 V and 100 μA when 6 μL of water was applied. The generator is also found to have a stable and reproducible response to other liquids. An output voltage of 0.3 V was obtained after 244, 876, 931, and 184 μs, on exposure of the generator to 6 μL of water, ethanol, acetone, and methanol, respectively. The fast response time and high sensitivity to liquids show that the device has great potential for the detection of small quantities of liquid. In addition, the simple easily implemented sequential EPD method ensures the high mechanical strength of the device. This compact, reliable device provides a new method for the sensitive, rapid detection of extraneous liquids before they can impact the performance of electronic circuits, particularly those on printed circuit board.


2008 ◽  
Vol 38 ◽  
pp. 238-247
Author(s):  
A.D. Davydov ◽  
V.S. Shaldaev

The initiation and development of pitting corrosion of steel 20Cr13 in the NaCl solutions with various concentrations, temperatures, and pH values are studied under the potentiostatic conditions and at the free-corrosion potential. The pitting and repassivation potentials are determined using the method of cycling voltammetry. In spite of the fact that thus determined pitting potential is more positive than the corrosion potential (the open-circuit potential Eo.c.), the long-term experiments, which were performed at the free-corrosion potential, showed that pitting corrosion takes place without imposing a potential using an external power source. It is concluded that the probability of pitting corrosion of steel should be determined by comparing the corrosion potential (the open-circuit potential) with the repassivation potential Erp. Steel 20Cr13 is prone to the pitting corrosion, because Erp is more negative than Eo.c.. In the potentiostatic experiments, the variation of the depth and diameter of pits and their number with the time and the effect of temperature and electrode rotation on the pit propagation are studied. The results, which were obtained at the free-corrosion potential, are much less reproducible. In this case, in contrast to the potentiostatic conditions, the pit depth increased only slightly and the pit width increased to a larger extent. The effect of concentration, pH value, and temperature of NaCl solutions on the pit propagation is considered. It is concluded that the data on the development of pitting corrosion under the potentiostatic conditions can be hardly extended to the conditions of free corrosion potential.


1990 ◽  
Vol 41 (3) ◽  
pp. 325-326
Author(s):  
Hidehiko KOBAYASHI ◽  
Miyuki KATOH ◽  
Hiroyuki SHIMODA ◽  
Takashi MITAMURA ◽  
Yoichi KAMEGAYA

2012 ◽  
Vol 524-527 ◽  
pp. 1115-1123 ◽  
Author(s):  
Jiu Shuai Deng ◽  
Shu Ming Wen ◽  
Shao Jun Bai ◽  
Mei Fang Xie ◽  
Hai Ying Shen

For low-grade iron ore, smelting costs and resource wastage will be increased. Product quality of such ore is affected adversely by an excessive amount of sulfur. This also causes environmental pollution. In accordance with the vanadium-titanium (V-Ti) magnetite concentrate properties with low iron grade and high sulfur content, the joint process of magnetic separation and flotation was carried out. Magnetic separation was conducted to increase the iron grade, while reverse flotation was used to reduce sulfur content. Results show that the feeding mainly contains titanomagnetite, hematite, and pyrite. The sulfur was primarily found in pyrite. The separation effect was influenced by the grinding fineness, magnetic intensity, collector type and dosage, and pH value. At a grinding fineness of −45 μm accounting for 87%, most of the iron minerals exhibited monomer dissociation. An open-circuit experiment was carried out under the best conditions of magnetic intensity, as well as collector and modifier dosage. Good experimental results were obtained as follows: the iron grade increased to 57.17%, iron recovery was 89.94%, sulfur content decreased from 0.66% to 0.26%, reverse flotation of sulfur foam concentrate contained almost 15.68% sulfur, the upgrade ratio was about 23, and the cobalt in the sulfur concentrate was enriched 20-fold. A method for improving the comprehensive utilization level and effect of mineral resources is provided in this study.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1358
Author(s):  
Donglou Ren ◽  
Xue Luo ◽  
Shuo Chen ◽  
Zhuanghao Zheng ◽  
Michel Cathelinaud ◽  
...  

Antimony selenide (Sb2Se3) has been widely investigated as a promising absorber material for photovoltaic devices. However, low open-circuit voltage (Voc) limits the power conversion efficiency (PCE) of Sb2Se3-based cells, largely due to the low-charge carrier density. Herein, high-quality n-type (Tellurium) Te-doped Sb2Se3 thin films were successfully prepared using a homemade target via magnetron sputtering. The Te atoms were expected to be inserted in the spacing of (Sb4Se6)n ribbons based on increased lattice parameters in this study. Moreover, the thin film was found to possess a narrow and direct band gap of approximately 1.27 eV, appropriate for harvesting the solar energy. It was found that the photoelectric performance is related to not only the quality of films but also the preferred growth orientation. The Te-Sb2Se3 film annealed at 325 °C showed a maximum photocurrent density of 1.91 mA/cm2 with a light intensity of 10.5 mW/cm2 at a bias of 1.4 V. The fast response and recovery speed confirms the great potential of these films as excellent photodetectors.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xin Li ◽  
Junjie Shi ◽  
Junchao Pang ◽  
Weihua Liu ◽  
Hongzhong Liu ◽  
...  

Graphene channel liquid container field effect transistor pH sensor with interdigital microtrench for liquid ion testing is presented. Growth morphology and pH sensing property of continuous few-layer graphene (FLG) and quasi-continuous monolayer graphene (MG) channels are compared. The experiment results show that the source-to-drain current of the graphene channel FET has a significant and fast response after adsorption of the measured molecule and ion at the room temperature; at the same time, the FLG response time is less than 4 s. The resolution of MG (0.01) on pH value is one order of magnitude higher than that of FLG (0.1). The reason is that with fewer defects, the MG is more likely to adsorb measured molecule and ion, and the molecules and ions can make the transport property change. The output sensitivities of MG are from 34.5% to 57.4% when the pH value is between 7 and 8, while sensitivity of FLG is 4.75% when thepH=7. The sensor fabrication combines traditional silicon technique and flexible electronic technology and provides an easy way to develop graphene-based electrolyte gas sensor or even biological sensors.


2013 ◽  
Vol 850-851 ◽  
pp. 12-15 ◽  
Author(s):  
Yan Shi ◽  
Yong Ping Liu ◽  
Yan Jun Xin

In this study, WO3/TiO2nanotube array photoelectrodes were fabricated by anodic oxidation and electro-deposition method. The effects of WO3, H2O2, oxygen, and pH value were investigated in the degradation of Dimethyl phthalate (DMP). Results show that the photocatalytic property of the photoelectrode was improved by the modification of WO3. The degradation rate of DMP was increased by 9.3% after 120min irradiation. H2O2could significantly promote the degradation of DMP. The degradation rate of DMP was increased by 27.9% and arrived 97.5% after 120 min irradiation. A certain amount of O2added to the solution had positive effect on the degradation of DMP. While excessive O2would undermine the degradation. The degradation rate of DMP was improved in both acidic condition and alkaline condition. It was separately increased by 38.4% and 40.2% at the pH value of 3.0 and 7.0, compared with that of pH = 7.


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