Zinc Electrodeposition in the Presence of an Aqueous Electrolyte Containing 1-Ethylpyridinium Bromide: Unexpected Oddities

2017 ◽  
Vol 70 (9) ◽  
pp. 1025 ◽  
Author(s):  
Max E. Easton ◽  
Lisa C. Player ◽  
Anthony F. Masters ◽  
Thomas Maschmeyer

The reversible electrodeposition of zinc was investigated in an aqueous electrolyte containing zinc bromide (50 mM) and 1-ethylpyridinium bromide ([C2Py]Br, 50 mM) by cyclic voltammetry, chronoamperometry, and scanning electron microscopy. Unusual voltammetric behaviour for the Zn/ZnII redox couple was observed in the presence of [C2Py]Br. Passivation of the redox couple was observed after a single deposition–stripping cycle at switching potentials more negative than −1.25 V versus Ag/AgCl. This unusual behaviour was attributed to the reduction of 1-ethylpyridinium cations to pyridyl radicals and their follow-up reactions, which influenced the zinc electrochemistry. This behaviour was further seen to modify the nucleation process of electrodeposition, which altered the morphology of zinc electrodeposits.

2005 ◽  
Vol 04 (02) ◽  
pp. 245-252 ◽  
Author(s):  
JING-RU WU ◽  
EDWIN JAHNGEN ◽  
KUANG-PANG LI ◽  
WAN-SUN TSE ◽  
PING CHIANG ◽  
...  

Vertically oriented multiple-walled carbon nanotubes (MWCNTs) aligned on a silicon substrate were covalently bonded with horseradish peroxidase (HRP) and used as biosensors or electrodes. The modified platform was investigated with Scanning Electron Microscopy (SEM), UV-Vis spectrophotometer and Cyclic Voltammetry (CV). The enzyme catalyzed reaction and the subsequent reduction of the enzymatic products by the platform were carefully investigated. The assay was done by measuring the absorbance of the dye formed from the reaction product of the substrates (phenol) and 4-aminoantipyrine. From the linear response, phenol can be quantitized in the range from 47 ppm to 750 ppm with a detection limit of 19 ppm (based on S/N = 3). The resulting modified aligned MWCNTs still exhibited enzymatic activities after storage of 13 days. The activity of the attached HRP was also demonstrated electrochemically.


2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Altuğ Kümbül ◽  
Ersen Turaç ◽  
Tuğba Dursun ◽  
Ertuğrul Şahmetlioğlu

AbstractElectrochemical copolymerization of N 1,N 3-bis(thiophene-3-ylmethylene)benzene-1,3-diamine (TMBA) with 3,4-ethylenedioxythiophene (EDOT) was carried out in a CH3CN/LiClO4 (0.1 M) solvent-electrolyte via potentiodynamic electrolysis. Chemical structure of the monomer was determined by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy. The resulting copolymer was characterized by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). Conductivity measurements of the copolymer and PEDOT (poly(3,4-ethylenedioxythiophene)) were carried out by the four-probe technique.


2014 ◽  
Vol 92 (12) ◽  
pp. 1139-1144 ◽  
Author(s):  
Tao-Tao Pang ◽  
Li-Ming Du ◽  
Hai-Long Liu ◽  
Yun-Long Fu

Numerous techniques have focused on the ability of p-sulfonated calix[n]arene to form complexes with tryptophan. Scanning electron microscopy and Fourier transform infrared spectroscopy were utilized to study the organization and molecular structure of different layers of the electrode surface. Scanning electron microscopy results showed that SC4A displayed a cubic structure whereas SC6A and SC8A displayed dendrite structures. The electrochemical properties and potential complex formation between SCnA and tryptophan were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetry experiments showed that the gold electrode was successfully functionalized by self-assembled cysteamine and SC4A. Electrochemical impedance spectroscopy results showed the observation of the tryptophan–SCnA interaction and indicated that SC4A had the highest sensitivity to tryptophan and allowed 2.04 μg L−1 tryptophan to be detected. Electrochemical impedance spectroscopy analysis and molecular modeling calculation confirmed that SC4A has higher tryptophan sensitivity than SC6A and SC8A.


2012 ◽  
Vol 512-515 ◽  
pp. 944-947 ◽  
Author(s):  
Jia Wei Deng ◽  
Huan Pang ◽  
Shao Mei Wang ◽  
Jiang Shan Zhang

Graphene oxide nanoplate-MnO2composites have been synthesized by oxidizing part of the carbon atoms in the framework of graphene oxide nanoplates at ambient temperature. The composites were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Their microstructures and morphologies have affected their electrochemical properties. Compared with MnO2nanoparticles, the nanocomposite prepared reveals better electrochemical properties as a supercapacitor electrode material.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 977
Author(s):  
Min Hee Joo ◽  
So Jeong Park ◽  
Hye Ji Jang ◽  
Sung-Min Hong ◽  
Choong Kyun Rhee ◽  
...  

Terpyridine-functionalized Ti nanospike electrodes (TiNS-SiTpy) were developed and applied to cyclic voltammetry and amperometry of Ln (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) ions and mixed Eu (III) + Ln (III) ions in a 0.1 M NaClO4 electrolyte. Electrodeposition was successfully performed over TiNS-SiTpy electrodes, which were fully examined by scanning electron microscopy, X-ray diffraction crystallography, Fourier-transform infrared spectroscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, photoluminescence (PL), and PL decay kinetics. The Gd and Tb ions were found to increase PL intensities with 10× longer lifetimes of 1.32 μs and 1.03 μs, respectively, compared with that of the electrodeposited Eu sample. The crystal phase and the oxidation states were fully examined for the mixed Ln (Eu + Gd and Eu + Tb) complex structures.


2014 ◽  
Vol 941-944 ◽  
pp. 1654-1658
Author(s):  
Dao Bing Huang ◽  
Yuan Qiang Tu ◽  
Jie Cai ◽  
Guan Wen Feng ◽  
Xing Peng Guo

In this study, the influence of sodium dodecylbenzenesulfonate (SDBS) as additive on the morphology and nucleation mechanism for zinc electrodeposition on steel sheet was investigated using scanning electron microscopy (SEM) and potentiostatic electrochemical techniques. From the analysis of the chronoamperometric transients and the SEM images, an instantaneous nucleation with 3D growth has been proposed in both baths with and without SDBS. It was found that the morphology of zinc electrodeposits varied from initial thin-layered hexagonal plates to a finer ridge and needle morphologies with increasing the overpotential as SDBS was added in the bath solution.


2018 ◽  
Vol 15 (1) ◽  
pp. 62
Author(s):  
Pandi Kurniawan ◽  
Erman Taer ◽  
Usman Malik ◽  
Rika Taslim

Activated carbon electrode have been prepare from durian shell focused in KOH concentration variations at chemical activation process. The preparation of carbon electrodes begins with pre-carbonization process, grinding using Hard Grinder and ball milling, after that followed by sieving process with particle size at range of 39 - 52 μm. Chemical activation was performed by using KOH activator agent with concentration variation of 0.5 M, 0.6 M, 0.7 M. Carbon powder are formed to pellet form using Hydraulic Press at a 8 ton compression pressure. The carbonization process is carried out a temperature of 600°C in the N2 gas atmosphere at a temperature of 900°C for 2 hours. The electrodes characterization are performed to determine the physical and electrochemical properties.The physical properties such as density, degree of cristanility, surface morfology was analyzed by calculate the electrode dimension such as, mass, thickness and diameter, X-ray diffraction analysis and Scanning Electron Microscopy Analysis. the electrochemical properties was studied the cell capacitance and the electrode capacitance specific using Cyclic Voltammetry method. the electrode density were decrease with the increasing the KOH concentration. The smallest density has been found at electrode using a KOH concentration of 0.7 M. The XRD test showed a carbon was amorfphuse structure identified by existing two broadening peaks at an angle of 2θ, ie 24.967°, 44.315° and 81.332° which describes the  (002), (100) and (112) planes. Furthermore, samples were analyzed by Scanning Electron Microscopy and X-ray diffraction. The  cyclic voltammetry result, obtained the highest specific capacitance of 89.05 F/g and cell capacitance 24,04 F was found at electrode with a KOH  concentration of 0.7 M. From this research it can be concluded that the KOH optimum concentration was 0.7 M.


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