Electrochemical noise study of the effect of electrode surface wetting on the evolution of electrolytic hydrogen bubbles

The growth of attached bubbles during the electrochemical evolution of hydrogen at a horizontal cathode at the base of a quiescent, dilute aqueous solution is analysed using a simple model of the process that includes the Butler–Volmer reaction model, the diffusion and migration of electroactive species and a symmetry condition that approximately accounts for the presence of periodically spaced bubbles on the electrode surface. The diffusion controlled growth of a bubble approximately follows a $t^{1/2}$ law when the spacing of the bubbles on the electrode is large, departing slightly from it due to the non-uniformity of the concentration of dissolved hydrogen in the supersaturated solution into which the bubble grows, and approaches a $t^{1/3}$ law when the spacing decreases. The space- and time-averaged current density increases exponentially with the applied voltage for an alkaline solution when the consumption of water in the reaction is not taken into account. For an acidic solution, the average current density saturates to a transport limited value that depends on bubble spacing. For a given voltage, the presence of attached bubbles increases the average current density due to the decrease of the concentration overpotential caused by the bubbles. The spacing of the bubbles on the electrode surface decreases when the voltage increases if the maximum supersaturation at the electrode is imposed to be constant. The result suggests that coalescence of attached bubbles will occur above a certain voltage.

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MEASURING ELECTROCHEMICAL NOISE RESISTANCE FROM A WIRE BEAM ELECTRODE SURFACE FOR CORROSION RATE AND PATTERN DETERMINATION

Fluctuation and Noise Letters ◽

10.1142/s021947750300152x ◽

2003 ◽

Vol 03 (04) ◽

pp. L419-L432 ◽

Cited By ~ 1

Author(s):

YONG-JUN TAN

Keyword(s):

Electrode Surface ◽

Electrochemical Noise ◽

Electrode Array ◽

Current Method ◽

Low Noise ◽

Noise Resistance ◽

Galvanic Current ◽

Corrosion Rates ◽

Pattern Determination ◽

Wire Beam Electrode

Electrochemical noise resistance (Rn), a new means of determining corrosion rates, has been considered to have only limited value since it offers little that cannot be achieved by conventional electrochemical methods. Aiming at overcome this limitation, a novel technique has been developed by combining the Rn method and an electrochemically-integrated electrode array namely the wire beam electrode (WBE). This combined Rn-WBE method effectively has extended the applicability of the Rn method from a uniform electrode surface to a nonuniform electrode surface. This present work is designed to examine the advantages and limitations of the Rn-WBE method in determining corrosion rates and patterns. The Rn-WBE method, together with other WBE based methods, was applied to corrosion systems of different characteristics. It was found that the Rn-WBE method has advantages over other WBE based methods when applying to a relatively uniform WBE surface. Both Rn-WBE method and the WBE based overpotential-galvanic current method were found to be similarly applicable to nonuniform WBE surfaces. However, the Rn-WBE method was found not applicable to low noise level corrosion systems. Some related issues regarding Rn calculation such as trend removal have also been clarified in this paper.

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Revisiting Gas to Solids Ratio for Activated Sludge Clarification by Electrolytic Hydrogen Bubbles: Theoretical and Experimental Evaluations

Catalysts ◽

10.3390/catal11111413 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1413

Author(s):

Jiseon Kim ◽

Chong Min Chung ◽

Kangwoo Cho ◽

Tai Hak Chung

Keyword(s):

Activated Sludge ◽

Water Electrolysis ◽

Green Energy ◽

Governing Parameter ◽

Hydraulic Loading ◽

Micro Particles ◽

Hydrogen Bubbles ◽

Electrolytic Hydrogen ◽

Practical Guidelines ◽

The Given

Molecular hydrogen (H2), as the green energy carrier from water electrolysis, can be utilized for separation of suspended micro-particles as electroflotation (EF). This study provides practical guidelines for the gas to solids (G/S) ratio as the governing parameter in EF, based on theoretical estimations and experiments for clarification of activated sludge. The G/S ratio in EF was controlled linearly by current density (j), under quasi-consistent current efficiency (at j > 8 mA/cm2) for H2 (~1) and O2 (~0.4) bubble generations on Ti cathode and IrTaOx anode, respectively. Based on the measured sizes of bubbles (approximated to 35 µm) and biological flocs (discretized to mean sizes of 22.5, 40, 60, 135, and 150 µm), batch flotation experiments estimated the maximum collision-attachment efficiency of 0.057. The rise velocities of floc-bubble aggregate were computed to derive the limiting G/S ratio to overcome the given influent hydraulic loading. Consequently, the estimates (5.23 × 10−4 and 5.92 × 10−4 at hydraulic loading of 0.87 and 1.73 cm/min, respectively) were compatible with the continuous EF experiments.

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A computational fluid dynamics study of hydrogen bubbles in an electrochemical reactor

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132005000400027 ◽

2005 ◽

Vol 48 (spe) ◽

pp. 219-229 ◽

Cited By ~ 5

Author(s):

Renata da Silva Cavalcanti ◽

Severino Rodrigues de Farias Neto ◽

Eudésio Oliveira Vilar

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Electrode Surface ◽

Electrochemical Reactor ◽

Liquid System ◽

Size Group ◽

Group Model ◽

Hydrodynamic Behavior ◽

Hydrogen Bubbles ◽

Reactor Hydrodynamics

Most electrochemical reactors present reactions with the growth and departure of gas bubbles which influence on the reactor hydrodynamics and this study is usually complex, representing a vast field for research. The present paper had as objective to study a bi-phase (gas-liquid) system aiming to foresee the influence of departure of hydrogen bubbles generated on effective electrode surface situated on cathodic semi-cell. Nevertheless, it was idealized that the gas was injected into the semi cell, through the effective electrode surface With this hypothesis, it was possible to study, and numerically analyze, the hydrodynamic behavior of the hydrogen bubbles in the interior of the study domain, applying concepts of computational fluid dynamics by using the computational applicative CFX-4 for the application of the MUSIG ("MUltiple-SIze-Group") model, taking into consideration the phenomena of coalescence and the distribution of the diameter of the bubbles.

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Kinetics of compact layer formation and growth of 1,10-phenanthroline at the electrode surface

Journal de Chimie Physique ◽

10.1051/jcp/1990871597 ◽

1990 ◽

Vol 87 ◽

pp. 1597-1607 ◽

Cited By ~ 2

Author(s):

L Benedetti ◽

M Borsari ◽

C Fontanesi ◽

G Battistuzzi Gavioli

Keyword(s):

Electrode Surface ◽

Layer Formation ◽

Compact Layer ◽

Kinetics Of

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Electrode-surface coordination/organometallic chemistry : iodine and carbon monoxide on well-ordered and oxidatively disordered Pd(111)

Journal de Chimie Physique ◽

10.1051/jcp/1991881591 ◽

1991 ◽

Vol 88 ◽

pp. 1591-1612 ◽

Cited By ~ 5

Author(s):

GM Berry ◽

ME Bothwell ◽

SL Michelhaugh ◽

JR McBride ◽

MP Soriaga

Keyword(s):

Carbon Monoxide ◽

Organometallic Chemistry ◽

Electrode Surface

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A Photo-ionization VOCs Sensor Developed the Resistance to Contamination of Electrode Surface

IEEJ Transactions on Sensors and Micromachines ◽

10.1541/ieejsmas.131.88 ◽

2011 ◽

Vol 131 (2) ◽

pp. 88-89

Author(s):

Yasuyuki Hirano ◽

Elito Kazawa ◽

Yoshiaki Haramoto ◽

Hiromichi Yoshida

Keyword(s):

Electrode Surface ◽

Photo Ionization

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Bio-Inspired Submicron Electrodes

MRS Proceedings ◽

10.1557/proc-775-p5.4 ◽

2003 ◽

Vol 775 ◽

Cited By ~ 1

Author(s):

Ivan Stanish ◽

Daniel A. Lowy ◽

Alok Singh

Keyword(s):

Electrode Surface ◽

Structural Integrity ◽

Electron Flow ◽

Charge Storage ◽

Electroactive Material ◽

Electron Coupling ◽

Strong Potential ◽

Electrical Potentials ◽

Submicron Scale ◽

Potential Gradients

AbstractImmobilized polymerized electroactive vesicles (IPEVs) are submicron biocapsules capable of storing charge in confined environments and chemisorbing on surfaces. Methods to immobilize stable submicron sized electroactive vesicles and the means to measure electroactivity of IPEVs at nanolevels have been demonstrated. IPEVs can withstand steep potential gradients applied across their membrane, maintain their structural integrity against surfaces poised at high/low electrical potentials, retain electroactive material over several days, and reversibly mediate (within the membrane) electron flow between the electrode surface and vesicle interior. IPEVs have strong potential to be used for charge storage and electron coupling applications that operate on the submicron scale and smaller.

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