The Potential-pH Diagram Depicting the Chemisorption of Two Species on the Uniformly Inhomogeneous Surface. The Sulfur and Hydrogen Chemisorption on the Platinum Electrode

1995 ◽  
Vol 60 (7) ◽  
pp. 1101-1108 ◽  
Author(s):  
Tomáš Loučka
Keyword(s):  
Thermodynamic Data ◽  
Platinum Electrode ◽  
Hydrogen Chemisorption ◽  
Inhomogeneous Surface

General thermodynamic dependences were derived for the simultaneous chemisorption of two substances on the uniformly inhomogeneous surface. In terms of these dependences and on the basis of thermodynamic data available in the literature, the potential-pH diagram was calculated for the Pt-S-H2O system at 25 °C on considering the sulfur and hydrogen chemisorption.

The Potential-pH Diagrams Depicting the Hydrogen Chemisorption in the Pt-H2O, Ir-H2O, and Rh-H2O Systems at 25 °C

1995 ◽  
Vol 60 (4) ◽  
pp. 553-558 ◽  
Author(s):  
Tomáš Loučka
Keyword(s):  
Thermodynamic Data ◽  
Hydrogen Chemisorption

Thermodynamic data for the chemisorption of hydrogen on the Pt, Ir, and Rh electrodes were evaluated from data in the literature. On the basis of these data, the potential-pH diagrams were calculated for the Pt-H2O, Ir-H2O, and Rh-H2O systems describing the hydrogen chemisorption. For the hydrogen chemisorption, the surface was considered to be uniformly inhomogeneous.

The efficiency of application of virtual cross-sections method and hypotheses MELS in problems of wave signal propagation in elastic waveguides with rough surfaces

2016 ◽  
pp. 3564-3575 ◽  
Author(s):  
Ara Sergey Avetisyan
Keyword(s):  
Half Space ◽  
Cross Sections ◽  
Classical Method ◽  
Signal Propagation ◽  
Elastic Half Space ◽  
Layered Systems ◽  
Surface Layers ◽  
Inhomogeneous Surface ◽  
Wave Signal ◽  
The Impact

The efficiency of virtual cross sections method and MELS (Magneto Elastic Layered Systems) hypotheses application is shown on model problem about distribution of wave field in thin surface layers of waveguide when plane wave signal is propagating in it. The impact of surface non-smoothness on characteristics of propagation of high-frequency horizontally polarized wave signal in isotropic elastic half-space is studied. It is shown that the non-smoothness leads to strong distortion of the wave signal over the waveguide thickness and along wave signal propagation direction as well.  Numerical comparative analysis of change in amplitude and phase characteristics of obtained wave fields against roughness of weakly inhomogeneous surface of homogeneous elastic half-space surface is done by classical method and by proposed approach for different kind of non-smoothness.

Electrodeposition of Cu2O Particles by Using Electrolyte Solution Containing Glucopone as Surfactant

2009 ◽  
Vol 1 (2) ◽  
pp. 18-20
Author(s):  
Dahyunir Dahlan
Keyword(s):  
Indium Tin Oxide ◽  
Pulse Current ◽  
Platinum Electrode ◽  
Saturated Calomel Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Continuous Current ◽  
Oxide Particles ◽  
Cupric Sulphate

Copper oxide particles were electrodeposited onto indium tin oxide (ITO) coated glass substrates. Electrodeposition was carried out in the electrolyte containing cupric sulphate, boric acid and glucopone. Both continuous and pulse currents methods were used in the process with platinum electrode, saturated calomel electrode (SCE) and ITO electrode as the counter, reference and working electrode respectively. The deposited particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that, using continuous current deposition, the deposited particles were mixture of Cu2O and CuO particles. By adding glucopone in the electrolyte, particles with spherical shapes were produced. Electrodeposition by using pulse current, uniform cubical shaped Cu2O particles were produced

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.

Comparison of Gold and Platinum Electrode Responses in Activated Sludge

1993 ◽  
Vol 28 (11-12) ◽  
pp. 473-480
Author(s):  
A. Heduit ◽  
B. Martin ◽  
I. Duchamp ◽  
D. R. Thevenot
Keyword(s):  
Electron Transfer ◽  
Activated Sludge ◽  
Gold Electrode ◽  
Platinum Electrode ◽  
Electrochemical Determination ◽  
Exchange Current ◽  
Experimental Conditions ◽  
Equilibrium Exchange ◽  
Prolonged Contact ◽  
Current Densities

Gold and platinum were compared to ascertain how they expressed a stabilized potential in activated sludge. The comparison was based on electrochemical determination of the electron transfer rate (i.e. equilibrium exchange current density) and recording of potentials against time. When both metals are treated in the same way, platinum gives equilibrium exchange current densities approx. 10 times higher than gold, both in aerated activated sludge and in treated water. For platinum, the equilibrium exchange current densities range from 0.1 to 0.25 µA/cm2 immediately after polishing and decrease during prolonged contact with activated sludge subjected to alternating aeration/anoxia sequences. The lower kinetics of electron transfer on gold go together with significant differences in response:- In an aerobic medium a gold electrode potential is lower than that of a platinum electrode. In a strongly anaerobic medium, the reverse is true. Consequently, the amplitude of the potential variation between aerobic and anaerobic media is smaller for gold than for platinum. Under our experimental conditions this amplitude was approx 350 mV for gold and 850 mV for platinum.- The slopes of the linear relationships between potential and pH or potential and the logarithm of the dissolved oxygen concentration are two or three times greater for platinum than for gold. Although the values obtained with platinum electrodes cannot represent a veritable equilibrium state, the platinum electrode zero-current potential would seem to be far more sensitive to variations in the medium than that of the gold electrode; it is, therefore, more suitable for use in activated sludge.

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