THE ELECTRODE BEHAVIOR OF MERCURY

1953 ◽  
Vol 31 (4) ◽  
pp. 306-318
Author(s):  
A. K. Wiebe ◽  
C. A. Winkler
Keyword(s):  
Sulphuric Acid ◽  
Metal Atom ◽  
Electrode Surface ◽  
Saturated Calomel Electrode ◽  
Mercury Electrode ◽  
Mercury Ions ◽  
Electrode Potentials ◽  
Constant Potential ◽  
First Time ◽  
Subsequent Passage

Mercury electrode potentials in N/5 sulphuric acid were unaffected when the electrolyte was saturated with hydrogen, nitrogen, or helium but were markedly affected by trace amounts of oxygen or mercury ions. In the absence of oxygen and mercury ions, a constant potential of −0.61 volt (relative to a saturated calomel electrode) was observed. When current was passed for the first time across a fresh electrode face immersed in oxygen-free electrolyte (i.e. from initial potentials of about −0.6l volt), the potential build-up was nonlinear, but subsequent passage of current gave a linear build-up of potential. With traces of oxygen present, differences in the two types of curves were masked by reactions that appeared to involve oxygen or oxide on the electrode surface. The initial build-up curve was ascribed to the deposition of a monatomic hydrogen film (one atom per metal atom in the surface). The potential build-up curves probably result from a number of simultaneous reactions at the electrode.

THE ELECTRODE BEHAVIOR OF COPPER

1953 ◽  
Vol 31 (11) ◽  
pp. 1118-1126 ◽  
Author(s):  
A. K. Wiebe ◽  
C. A. Winkler
Keyword(s):  
Sulphuric Acid ◽  
Electrode Surface ◽  
Copper Cathode ◽  
Dissolved Gas ◽  
Copper Electrodes ◽  
Surface Areas ◽  
Potential Decay ◽  
The Times ◽  
First Time ◽  
Subsequent Passage

Potentials ranging from −0.063 volt to +0.044 volt were observed for freshly prepared copper electrodes in sulphuric acid. The potential was dependent upon concentration of the electrolyte, the gas with which the electrolyte was saturated, the nature of the electrode surface, and the intensity of the stirring. The rate of potential decay was influenced by the nature of the dissolved gas and concentration of the electrolyte. When current was passed for the first time across a freshly prepared electrode face, the potential build-up was nonlinear, but subsequent passage of current gave a linear build-up of potential. The apparent capacitance at a copper cathode increased with the time allowed for the potential to decay after current had been passed. It was also dependent upon the current used to measure it, and appeared to be somewhat affected by the area of the cathode. Reliable estimates of the surface areas of the electrodes appeared to be possible from the times required for the electrodes to reach maximum potentials.

The Effect of p-Toluidine on the Two-Step Electroreduction of Zn(II) in Water-Methanol and Water-Dimethylformamide

1999 ◽  
Vol 64 (4) ◽  
pp. 585-594 ◽  
Author(s):  
Barbara Marczewska
Keyword(s):  
Electron Transfer ◽  
Binary Mixtures ◽  
Rate Constant ◽  
Rate Constants ◽  
Electrode Surface ◽  
Mercury Electrode ◽  
Forward Rate ◽  
Solvent Molecules ◽  
Activated Complex

The acceleration effect of p-toluidine on the electroreduction of Zn(II) on the mercury electrode surface in binary mixtures water-methanol and water-dimethylformamide is discussed. The obtained apparent and true forward rate constants of Zn(II) reduction indicate that the rate constant of the first electron transfer increases in the presence of p-toluidine. The acceleration effect may probably be accounted for by the concept of the formation on the mercury electrode an activated complex, presumably composed of p-toluidine and solvent molecules.

Influence of Partial Blocking of the Electrode Surface on the Transfer Coefficients

1993 ◽  
Vol 58 (3) ◽  
pp. 496-505
Author(s):  
Ondřej Wein
Keyword(s):  
Surface Activity ◽  
Elliptic Problem ◽  
Electrode Surface ◽  
Driving Force ◽  
Two Dimensional ◽  
Transfer Coefficients ◽  
Constant Potential ◽  
Numeric Solution ◽  
Active Zones ◽  
Partial Blocking

Partial blocking of the transport surface under the stagnant (nerst) layer is simulated by periodically alternating bands of perfectly insulating zones and active zones with a constant potential of driving force. The numeric solution of the corresponding two-dimensional elliptic problem is represented by a simple empirical correlation for the transfer coefficients. The result is interpreted in terms of a simple electrochemical problem about limiting diffusion currents at electrodes with non-uniform surface activity.

scholarly journals Synthesis of novel adsorbent based on tetrasulfide-functionalized fibrous silica KCC-1 for removal of Hg(II) cations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Azam Marjani ◽  
Reza Khan Mohammadi
Keyword(s):  
Effective Interaction ◽  
Sol Gel ◽  
Aqueous Media ◽  
Synthesis Method ◽  
Mercury Ions ◽  
Toxic Heavy Metals ◽  
Uptake Capacity ◽  
Hydrothermal Preparation ◽  
Ultrasonic Assisted ◽  
First Time

AbstractHg(II) has been identified to be one of the extremely toxic heavy metals because of its hazardous effects and this fact that it is even more hazardous to animals than other pollutants such as Ag, Au, Cd, Ni, Pb, Co, Cu, and Zn. Accordingly, for the first time, tetrasulfide-functionalized fibrous silica KCC-1 (TS-KCC-1) spheres were synthesized by a facile, conventional ultrasonic-assisted, sol–gel-hydrothermal preparation approach to adsorb Hg(II) from aqueous solution. Tetrasulfide groups (–S–S–S–S–) were chosen as binding sites due to the strong and effective interaction of mercury ions (Hg(II)) with sulfur atoms. Hg(II) uptake onto TS-KCC-1 in a batch system has been carried out. Isotherm and kinetic results showed a very agreed agreement with Langmuir and pseudo-first-order models, respectively, with a Langmuir maximum uptake capacity of 132.55 mg g–1 (volume of the solution = 20.0 mL; adsorbent dose = 5.0 mg; pH = 5.0; temperature: 198 K; contact time = 40 min; shaking speed = 180 rpm). TS-KCC-1was shown to be a promising functional nanoporous material for the uptake of Hg(II) cations from aqueous media. To the best of our knowledge, there has been no report on the uptake of toxic Hg(II) cations by tetrasulfide-functionalized KCC-1 prepared by a conventional ultrasonic-assisted sol–gel-hydrothermal synthesis method.

Electrochemical study of the mechanism and kinetics of reductive glycoside elimination of adriamycin adsorbed on a mercury electrode surface

1987 ◽  
Vol 225 (1-2) ◽  
pp. 187-204 ◽  
Author(s):  
Kenji Kano ◽  
Tomonori Konse ◽  
Keiko Hasegawa ◽  
Bunji Uno ◽  
Tanekazu Kubota
Keyword(s):  
Electrode Surface ◽  
Mercury Electrode ◽  
Electrochemical Study ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Sphere-like CoS with nanostructures as peroxidase mimics for colorimetric determination of H2O2 and mercury ions

RSC Advances ◽  
2016 ◽  
Vol 6 (71) ◽  
pp. 66963-66970 ◽  
Author(s):  
Haiguan Yang ◽  
Junqi Zha ◽  
Peng Zhang ◽  
Yuhao Xiong ◽  
Linjing Su ◽  
...  
Keyword(s):  
Solvothermal Method ◽  
Analytical Techniques ◽  
Colorimetric Determination ◽  
Mercury Ions ◽  
Peroxidase Mimics ◽  
First Time ◽  
Facile Solvothermal Method

CoS, which was prepared using a facile solvothermal method, and characterized using various analytical techniques, was demonstrated for the first time to exhibit intrinsic peroxidase-like activity.

Ion chemistry of transition metals in hydrocarbon flames. II. Cations of Sc, Ti, V, Cr, and Mn

1988 ◽  
Vol 66 (9) ◽  
pp. 2219-2228 ◽  
Author(s):  
John M. Goodings ◽  
Quang Tran ◽  
Nicholas S. Karellas
Keyword(s):  
Transition Metals ◽  
Metal Atom ◽  
Chemical Ionization ◽  
Metallic Ions ◽  
Ion Chemistry ◽  
Hydrocarbon Flames ◽  
Basic Series ◽  
First Time ◽  
Isomeric Structures

The same fuel-rich, premixed, conical, methane–oxygen flame at 2200 K and atmospheric pressure used for studies of Fe, Co, Ni, Cu, and Zn in Part I (1) is doped with the same concentration (~1 ppm) of Sc, Ti, V, Cr, and Mn to complete the first row of ten transition metals. Metallic ions of these metals and their compounds formed by chemical ionization reactions with H3O+ are observed by sampling the flame through a nozzle into a quadrupole mass spectrometer. Concentration profiles of individual and total cations are measured as a function of distance along the flame axis, and also mass spectra at a fixed point in the burnt gas. If A is the metal atom, the observed ions can be represented by four hydrate series including (a) A+•nH2O, (b) AOH+•nH2O, (c) AO+•nH2O, and (d) AO2H+•nH2O with n = 0–3 or 4, giving a maximum of four ligands around the metal atom. However, alternative isomeric structures are possible for each of the four basic series (e.g. AO+•2H2O ~ A(OH)2+•H2O ~ A(OH)3H+). The ions observed with Cr and Mn, in common with those of Fe, Co, Ni, and Cu, strongly favour series (a). On the other hand, Sc is completely different; the ions of series (c) are dominant. All four series are observed with each of Ti and V. Series (b) dominates for Ti and series (c) for V; ions from series (d) were observed for the first time. The ion chemistry of these metals is discussed in detail with emphasis on the probable chemical ionization reactions responsible for metallic ion formation. The pre-eminent role of proton transfer processes is apparent.

Photochemical reactions of azo compounds. IX. Further studies related to the photochemical reactions of bisazo compounds

1967 ◽  
Vol 20 (2) ◽  
pp. 321 ◽  
Author(s):  
NC Jamieson ◽  
GE Lewis
Keyword(s):  
Sulphuric Acid ◽  
Photochemical Reaction ◽  
Photochemical Reactions ◽  
Azo Compounds ◽  
Bisazo Compounds ◽  
First Time

The photochemical reactions of 4,4?-bis(phenylazo)biphenyl and 4- phenyl-azoazobenzene in 98% sulphuric acid have been examined, for comparison with the corresponding reactions in 22N acid. Photochemical cyclodehydrogenation of 4-phenylazoazobenzene to two benzo[c]cinnoline derivatives has thereby been effected for the first time. The observed course of the latter reaction has led, in turn, to studies of the benzidine rearrangement of 2-(2-phenylhydrazino)benzo[c]- cinnoline, of the photochemical cyclodehydrogenation of 3-phenylazobenzene, and of the photochemical reaction of 2-phenylazobenzo[c]cinnoline. The results of these investigations are now recorded and discussed.

THE ELECTRODE BEHAVIOR OF PLATINUM

1953 ◽  
Vol 31 (7) ◽  
pp. 665-672
Author(s):  
A. K. Wiebe ◽  
C. A. Winkler
Keyword(s):  
Sulphuric Acid ◽  
Saturated Calomel Electrode ◽  
Platinum Electrodes ◽  
Platinum Surface ◽  
Surface Areas ◽  
The Times

A potential of −0.305 ± 0.005 volt (relative to a saturated calomel electrode) was obtained at a freshly prepared platinum surface within 30 sec. of immersion in oxygen-free N/5 sulphuric acid saturated with hydrogen. In electrolytes saturated with nitrogen or oxygen potentials of +0.05 ± 0.01 volt and +0.745 ± 0.005 volt respectively were more slowly attained. The times required for the electrode to reach maximum potentials, tmax, when it was made a cathode, and corresponding values of tmax when it was rendered anodic, were determined over a range of currents. The values of tmax appear to provide a method of determining the surface areas of platinum electrodes.

Effect of Metal Modification to Carbon Paper Anodes on the Performance of Yeast-Based Microbial Fuel Cells Part Ι: In the Case without Exogenous Mediator

2013 ◽  
Vol 534 ◽  
pp. 76-81 ◽  
Author(s):  
Enas Taha Kasem ◽  
Takuya Tsujiguchi ◽  
Nobuyoshi Nakagawa
Keyword(s):  
Electron Transfer ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Thin Layer ◽  
Electrode Surface ◽  
Microbial Fuel Cells ◽  
Yeast Cells ◽  
Carbon Paper ◽  
Electrode Potentials ◽  
Different Thickness

Effect of modification of carbon paper with a thin layer of cobalt or gold on the performance of yeast-based microbial fuel cells was investigated. The modification was conducted by depositing Co or Au thin layer with different thickness, 5 nm and 30 nm, using a sputtering technique. The electrode performance was evaluated by measuring the electrode potentials and the fuel cell power output. The Co modification significantly increased the performance of the fuel cell, while the Au modification inhibited the performance. SEM observation indicated that the adhesion density of the yeast cells on the electrode surface was affected by the metals. It was confirmed that the electron transfer took place through the surface confined species at the mediatorless anode.

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