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

Materials ◽  
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.

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

Clay Minerals ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 501-510 ◽  
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%).

scholarly journals Electrochemical Glucose Oxidation Using Glassy Carbon Electrodes Modified with Au-Ag Nanoparticles: Influence of Ag Content

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Nancy Gabriela García-Morales ◽  
Luis Alfonso García-Cerda ◽  
Bertha Alicia Puente-Urbina ◽  
Leonor María Blanco-Jerez ◽  
René Antaño-López ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Electrode Surface ◽  
Glucose Oxidation ◽  
Modified Electrodes ◽  
Alkaline Media ◽  
Carbon Electrodes ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Glassy Carbon Electrodes ◽  
Transmission Electron

This paper describes the application of glassy carbon modified electrodes bearing Aux-Agynanoparticles to catalyze the electrochemical oxidation of glucose. In particular, the paper shows the influence of the Ag content on this oxidation process. A simple method was applied to prepare the nanoparticles, which were characterized by transmission electron microscopy, Ultraviolet-Visible spectroscopy, X-ray diffraction spectroscopy, and cyclic voltammetry. These nanoparticles were used to modify glassy carbon electrodes. The effectiveness of these electrodes for electrochemical glucose oxidation was evaluated. The modified glassy carbon electrodes are highly sensitive to glucose oxidation in alkaline media, which could be attributed to the presence of Aux-Agynanoparticles on the electrode surface. The voltammetric results suggest that the glucose oxidation speed is controlled by the glucose diffusion to the electrode surface. These results also show that the catalytic activity of the electrodes depends on the Ag content of the nanoparticles. Best results were obtained for the Au80-Ag20nanoparticles modified electrode. This electrode could be used for Gluconic acid (GA) production.

Voltammetric stabilization of electrofaceted (100)-type platinum electrodes in acidic solutions

1988 ◽  
Vol 66 (9) ◽  
pp. 2259-2267 ◽  
Author(s):  
Sara Alfonsina Dora Aldabe De Bilmes ◽  
María Cristina Giordano ◽  
Alejandro Jorge Arvia
Keyword(s):  
Competitive Adsorption ◽  
Co Adsorption ◽  
Surface Modifications ◽  
Electrolyte Composition ◽  
Potential Range ◽  
Platinum Electrodes ◽  
Potential Cycling ◽  
Acidic Solutions ◽  
Solution Interface ◽  
Pt Electrodes

The voltammetric stabilization of electrofaceted (100)-type Pt electrodes prepared from polycrystalline Pt by fast repetitive triangular potential cycling are followed by conventional voltammetry in the H-electroadsorption/electrodesorption potential range in either 1 M H2SO4 (0 to 35 °C) or 0.5 M HClO4 (−2 to 35 °C). The influence of CO adsorption on the stabilized voltammetric profile is also considered. Depending on the potential cycling used in conventional voltammetry, two well-defined stabilized profiles at 0.1 V/s in the H-electroadsorption/electrodesorption range can be obtained, namely, that corresponding to the H-adsorption stabilized electrofaceted (100)-type Pt, and that related to the O-adsorption stabilized electrofaceted (100)-type Pt.The changes in the conventional voltammetric profiles can be interpreted in terms of surface modifications basically associated with either adsorption or electroadsorption processes. The influence of the anion (electrolyte composition) prevailing in solution is accounted for in terms of a competitive adsorption between anions and H-adatoms. The influence of temperature in the range covered by this work is smaller than that of the structure of the solution at the electrode/solution interface.

Charge Transfer Property of Self-Assembled Viologen Derivative by Electrochemical Quartz Crystal Microbalance Response

2006 ◽  
Vol 6 (11) ◽  
pp. 3657-3660 ◽  
Author(s):  
Dong-Yun Lee ◽  
A. K. M. Kafi ◽  
Sang-Hyun Park ◽  
Young-Soo Kwon
Keyword(s):  
Charge Transfer ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Modified Electrodes ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Frequency Change ◽  
Self Assembled Monolayer ◽  
Transfer Property ◽  
Redox Peak ◽  
Self Assembled

Viologen modified electrodes have been extensively investigated with quartz crystal microbalance (QCM), which has been known as a nano-gram order mass detector, because of their highly reversible electrochemical properties, especially the first reduction-oxidation cycle of V2+ ↔ V•+. The purpose of this work was to study the charge transfer characteristics of self-assembled monolayer (SAM) by changing electrolyte solutions where the cations and anions are different. The redox peak currents were nearly equal charges during redox processes and showed an excellent linear interrelation between the scan rates and second redox peak currents. The charge transfer of self-assembled viologen monolayer was determined by the mass change during the cyclic voltammetry (CV). The total frequency change was about 17.8 Hz, 19.6 Hz, 9.5 Hz, and 8.4 Hz. From this data, we could know the transferred mass was about 19.0 ng, 20.9 ng, 10.2 ng, and 9.0 ng. Finally, the electrochemical quartz crystal microbalance (EQCM) has been employed to monitor the electrochemically induced adsorption of self-assembled monolayer.

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