Correlation between electrode surface coverage and the rate of inhibition of Pb(II) reduction process at the DME in HClO4 solutions

Improving surface selectivity and maximizing electrode surface area are critical needs for the electroreduction of nitrate. Herein, preferential (100) oriented Pt nanoflowers with an extended surface area were prepared by potentiostatic deposition on carbon cloth (Pt NFs/CC), and then Cu atoms were adsorbed on the Pt NFs (Cu/Pt NFs/CC) for application of nitrate electroreduction. The results reveal that Cu/Pt NFs/CC with 8.7% Cu coverage exhibits a high selectivity for nitrate electroreduction to N2 following two steps: Nitrate firstly converts into nitrite on Cu sites adsorbed on Pt NFs, then nitrite subsequently selective reduction and ammonia oxidation to N2 occur on the large exposed (100) terraces in Pt NFs. In addition, electrocatalytic activity and selectivity of nitrate reduction strongly rely on the Cu surface coverage on Pt NFs, the lower activity of nitrate reduction is displayed with increase of Cu coverage. Accordingly, the selective reduction of nitrate to N2 is feasible at such nanostructured Pt nanoflowers modified with Cu.

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The effect of the variation of potential on progressive three-dimensional nucleation and growth

Canadian Journal of Chemistry ◽

10.1139/v78-098 ◽

1978 ◽

Vol 56 (5) ◽

pp. 606-612 ◽

Cited By ~ 4

Author(s):

Stephen Fletcher ◽

Arthur Smith

Keyword(s):

Electrode Surface ◽

Surface Coverage ◽

Three Dimensional ◽

Nucleation And Growth ◽

Feedback Loops ◽

Linear Potential ◽

Applied Potential ◽

Potential Sweep ◽

Coverage Function

The effect of varying the applied potential during progressive three-dimensional nucleation and growth is described. The assumed model is that due to Armstrong, Fleischmann, and Thirsk in which expanding nuclei are considered to be right circular cones distributed at random on the electrode surface. The present work extends the previous potentiostatic approach by considering that the electrode surface coverage function responds instantaneously to small changes of applied potential. Under these circumstances we show that it is possible to calculate in an exact way the theoretical response of the model to various applied potential waveforms. In particular, the linear potential sweep and the staircase potential ramp are considered, as well as feedback loops generated by uncompensated ohmic overpotential. Certain limiting cases are derived which may be tested by experiment.

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Probing oxygen reduction and oxygen evolution reactions on bifunctional non-precious metal catalysts for metal–air batteries

RSC Advances ◽

10.1039/c6ra13414a ◽

2016 ◽

Vol 6 (75) ◽

pp. 71122-71133 ◽

Cited By ~ 13

Author(s):

Thirupathi Thippani ◽

Sudip Mandal ◽

Guanxiong Wang ◽

Vijay K. Ramani ◽

R. Kothandaraman

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Oxygen Evolution ◽

Electrode Surface ◽

Precious Metal ◽

Surface Coverage ◽

Reduction Reaction ◽

Metal Catalysts ◽

Reaction Intermediates ◽

Precious Metal Catalysts

Increase in surface coverage by oxygen reduction reaction intermediates with increase in overpotential impeding diffusion of oxygen to the electrode surface.

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The impact of surface coverage on the kinetics of electron transfer through redox monolayers on a silicon electrode surface

Electrochimica Acta ◽

10.1016/j.electacta.2015.10.125 ◽

2015 ◽

Vol 186 ◽

pp. 216-222 ◽

Cited By ~ 16

Author(s):

Simone Ciampi ◽

Moinul H. Choudhury ◽

Shahrul Ainliah Binti Alang Ahmad ◽

Nadim Darwish ◽

Anton Le Brun ◽

...

Keyword(s):

Electron Transfer ◽

Electrode Surface ◽

Surface Coverage ◽

The Impact ◽

Kinetics Of

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Deposition of two natural clays on a Pt surface using potentiostatic and spin-coating techniques: a comparative study

Clay Minerals ◽

10.1180/claymin.2008.043.3.13 ◽

2008 ◽

Vol 43 (3) ◽

pp. 501-510 ◽

Cited By ~ 3

Author(s):

A. A. Issa ◽

Y. S. Al-Degs ◽

N. A. Al-Rabady

Keyword(s):

Electrode Surface ◽

Spin Coating ◽

Surface Coverage ◽

Platinum Electrode ◽

Modified Electrodes ◽

Deposition Process ◽

Metallic Surface ◽

Stoichiometric Ratio ◽

Maximum Surface ◽

Natural Clays

AbstractTwo natural clays (kaolinite and montmorillonite) were deposited onto a platinum electrode surface using two deposition techniques and under different experimental variables. For both clays, the percentages of surface coverage (%θ) were optimized in the 75–96% range. A greater surface coverage was observed at higher temperatures for both clays, which confirms the endothermic nature of the deposition process. The maximum surface coverage (96%) was achieved for kaolinite. The surface coverage of kaolinite on a platinum electrode was constant for deposition times between 6 and 20 h. A surface coverage of 91% with montmorillonite particles was achieved. There was a very small increase in surface coverage by increasing the concentration of clay in the modified solution. The maximum surface coverage was observed under acidic conditions and smaller coverage values were reported for neutral and basic solutions. For both clays, a complete surface coverage for the electrode surface was achieved using the spin-coating technique. The experimental variables that affect the deposition of the clay, such as the stoichiometric ratio of clay/PVC and centrifugation speed and time, were studied and optimized to obtain full surface coverage. The spin-coating method achieved the required durability and stability for the modified-electrode. The characterization showed that the metallic surface chemistry of the platinum electrode was totally suppressed. Both modified electrodes were found to be useful for determination of Ag(I) ion with a detection limit as small as 1.00×10–10 M. The analytical precision was also satisfactory (RSD <5.0%).

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Study on Supercapacity Properties of Manganese Dioxide Active Material by the Cation Concentration Change on the Electrode Surface

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.2411 ◽

2013 ◽

Vol 734-737 ◽

pp. 2411-2414

Author(s):

Jian Min Zhang ◽

Pan Wang ◽

Gao Peng Zhang ◽

Ya Wei Li ◽

Ting Cao

Keyword(s):

Manganese Dioxide ◽

Electrode Surface ◽

Active Material ◽

Reduction Process ◽

Potassium Ion ◽

Ion Concentration ◽

Discharge Process ◽

Concentration Change ◽

Supercapacitor Electrode ◽

Cation Concentration

A four-electrode system was developed to measure in-situ the cation concentration change on the supercapacitor electrode surface for the first time during the charge/discharge process. While the MnO2 electrode was used in a supercapacitor in K2SO4 solution, the potassium ion concentration on the electrode surface was reversible change during the charging/discharging process, decreasing with the reduction process and increasing with the oxidation process. It is clearly clarified that the charge storage mechanism of manganese dioxide, as a supercapacitor active material, involves a fast redox reaction through reversible insertion/desertion of potassium ion and variation of manganese valance.

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Electrocatalytic Properties of Ni(II) Schiff Base Complex Polymer Films

Materials ◽

10.3390/ma15010191 ◽

2021 ◽

Vol 15 (1) ◽

pp. 191

Author(s):

Danuta Tomczyk ◽

Wiktor Bukowski ◽

Karol Bester ◽

Michalina Kaczmarek

Keyword(s):

Electrode Surface ◽

Surface Coverage ◽

Schiff Base Complex ◽

Modified Electrodes ◽

Electrochemical Quartz Crystal Microbalance ◽

Platinum Electrodes ◽

Rotating Disc ◽

Solution Interface ◽

Electrode Method ◽

Complex Polymer

Platinum electrodes were modified with polymers of the (±)-trans-N,N′-bis(salicylidene)-1,2-cyclohexanediaminenickel(II) ([Ni(salcn)]) and (±)-trans-N,N′-bis(3,3′-tert-Bu-salicylidene)-1,2-cyclohexanediaminenickel(II) ([Ni(salcn(Bu))]) complexes to study their electrocatalytic and electroanalytical properties. Poly[Ni(salcn)] and poly[Ni(salcn(Bu))]) modified electrodes catalyze the oxidation of catechol, aspartic acid and NO2−. In the case of poly[Ni(salcn)] modified electrodes, the electrocatalysis process depends on the electroactive surface coverage. The films with low electroactive surface coverage are only a barrier in the path of the reducer to the electrode surface. The films with more electroactive surface coverage ensure both electrocatalysis inside the film and oxidation of the reducer directly on the electrode surface. In the films with the most electroactive surface coverage, electrocatalysis occurs only at the polymer–solution interface. The analysis was based on cyclic voltammetry, EQCM (electrochemical quartz crystal microbalance) and rotating disc electrode method.

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The microstructure of functionalized poLyacrylonitrile beads for bioseparations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178604 ◽

1990 ◽

Vol 48 (4) ◽

pp. 1094-1095

Author(s):

Eduardo A. Kamenetzky ◽

David A. Ley

Keyword(s):

Aqueous Solution ◽

Affinity Chromatography ◽

Pore Size Distribution ◽

Pore Size ◽

Surface Coverage ◽

Vacuum Impregnation ◽

Thin Sections ◽

Selective Staining ◽

Low Viscosity ◽

Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

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