scholarly journals Coloring and Lightfastness of Anodized Aluminum with Organic Pigment Using Electrochemical Reduction of Surfactant with an Azobenzene Moiety

2021 ◽  
Vol 72 (6) ◽  
pp. 359-363
Author(s):  
Tetsuo SAJI
Keyword(s):  
Electrochemical Reduction ◽  
Anodized Aluminum ◽  
Organic Pigment ◽  
Azobenzene Moiety

scholarly journals Determination of Crystal Growth Geometry Factors and Nucleation Site Densities of Electrodeposited Ferromagnetic Cobalt Nanowire Arrays

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 142 ◽  
Author(s):  
Ryusei Saeki ◽  
Takeshi Ohgai
Keyword(s):  
Crystal Growth ◽  
Electrochemical Reduction ◽  
Spontaneous Magnetization ◽  
Frequency Factor ◽  
Nucleation Site ◽  
Nanowire Arrays ◽  
Crystal Nucleation ◽  
Anodized Aluminum ◽  
Cobalt Electrodeposition ◽  
Ferromagnetic Cobalt

The time-dependence of electrochemical reduction current, which was observed during the one-dimensional (1-D) crystal growth of ferromagnetic cobalt nanowire arrays, was analyzed by Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. Textured hcp-Co nanowire arrays were synthesized by potentio-static electrochemical reduction of Co2+ ions in anodized aluminum oxide (AAO) nanochannel films. Crystal growth geometry factor n in the JMAK equation was determined to be ca. 1. Hence, the electrochemical crystal growth process of a numerical nanowires array can be explained by 1-D geometry. The crystal nucleation frequency factor, k in JMAK equation was estimated to be the range between 10−4 and 10−3. Our experimental results revealed that the crystal nucleation site density Nd increased up to 2.7 × 10−8 nm−3 when increasing the overpotential for cobalt electrodeposition by shifting the cathode potential down to −0.85 V vs. Ag/AgCl. The (002) crystal orientation of hcp-Co nanowire arrays was, remarkably, observed by decreasing Nd. Spontaneous magnetization behavior was observed in the axial direction of nanowires. By decreasing the overpotential for cobalt electrodeposition, the coercivity of the nanocomposite film increased and reached up to 1.88 kOe, with a squareness of ca. 0.9 at room temperature.

Optimization of Aluminum Anodizing and Coloring Process Employing Organic Pigment

2014 ◽  
Vol 805 ◽  
pp. 137-142 ◽  
Author(s):  
Guilherme José Turcatel Alves ◽  
Sandra Masetto Antunes ◽  
Andre Lazarin Gallina ◽  
Guilherme Arielo Rodrigues Maia ◽  
Paulo Rogério Pinto Rodrigues
Keyword(s):  
Open Circuit Potential ◽  
Electrolyte Concentration ◽  
Charge Transfer Resistance ◽  
Open Circuit ◽  
Anodized Aluminum ◽  
Organic Pigment ◽  
Transfer Resistance ◽  
Optical Micrograph ◽  
Potentiostatic Polarization ◽  
Aluminum Anodizing

The process of aluminum anodizing forms an oxide layer constituted of nanotubes where it is possible to insert compounds, amongst these are the pigments and dyes. This study has as its main aim to study the behavior of aluminum alloy 6000, anodized and dyed with monolite red in Na2SO4 0.5 mol L-1 and pH = 4. The techniques employed were: anodic potentiostatic polarization, open circuit potential, chemometry, polarization resistance and optical micrograph. The factorial planning was proposed using four variables (anodizing time, current density, electrolyte concentration, and dye), the response to the planning was the charge transfer resistance. Polarization curves revealed that the anodized and dyed aluminum samples are much more resistant than the non-anodized aluminum. Optical microscopy analyses demonstrated that the dissolution of dye occurs in the solution, but not enough to break the film. As the main result, efficient coloring of aluminum parts was verified with reduction in costs in relation to the energy employed in the process, associated to reduction in time spent for the anodizing process, which makes it suitable to increase industrial production of dyed aluminum parts.

In Situ X-Ray Absorption Studies of the Electrochemical Reduction of Hydroxocobalamin

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-619-C2-620 ◽  
Author(s):  
M. Giorgett ◽  
I. Ascone ◽  
M. Berrettoni ◽  
S. Zamponi ◽  
R. Marassi
Keyword(s):  
Electrochemical Reduction ◽  
X Ray ◽  
Absorption Studies ◽  
X Ray Absorption

Time response of anodized aluminum pressure-sensitive paint

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1944-1949
Author(s):  
Hirotaka Sakaue ◽  
John P. Sullivan
Keyword(s):  
Time Response ◽  
Pressure Sensitive Paint ◽  
Anodized Aluminum ◽  
Pressure Sensitive

Lateral Adsorbate Interactions Inhibit HCOO- While Promoting CO Selectivity for CO2 Electrocatalysis on Ag

2018 ◽  
Author(s):  
Divya Bohra ◽  
Isis Ledezma-Yanez ◽  
Guanna Li ◽  
Wiebren De Jong ◽  
Evgeny A. Pidko ◽  
...  
Keyword(s):  
Electrochemical Reduction ◽  
Experimental Approach ◽  
Decisive Role ◽  
Experimental Methods ◽  
Reaction Intermediates ◽  
Intermediate Species ◽  
Experimental Knowledge ◽  
Complex Interactions ◽  
Ag Catalysts

<p>The analysis presented in this manuscript helps bridge an important fundamental discrepancy between the existing theoretical and experimental knowledge regarding the performance of Ag catalysts for CO<sub>2</sub> electrochemical reduction (CO<sub>2</sub>ER). The results demonstrate how the intermediate species *OCHO is formed readily en-route the HCOO<sup>– </sup>pathway and plays a decisive role in determining selectivity of a predominantly CO producing catalyst such as Ag. Our theoretical and experimental approach develops a better understanding of the nature of competition as well as the complex interactions between the reaction intermediates leading to CO, HCOO<sup>–</sup> and H<sub>2</sub> during CO<sub>2</sub>ER.</p><p><br></p><p>Details of computational and experimental methods are present in the Supporting Information provided. </p><p><br></p><p><br></p>

Photochemical and Electrochemical Reduction of Carbon Dioxide Catalyzed by a Polyoxometalate-Organic Photosensitizer Complex

2018 ◽  
Author(s):  
Chandan Dey ◽  
Ronny Neumann
Keyword(s):  
Carbon Dioxide ◽  
Cyclic Voltammetry ◽  
Formic Acid ◽  
Electrochemical Reduction ◽  
Mass Spectroscopy ◽  
Photochemical Reactions ◽  
Reducing Agent ◽  
Covalent Attachment ◽  
Hybrid Complex ◽  
Open Face

<p>A manganese substituted Anderson type polyoxometalate, [MnMo<sub>6</sub>O<sub>24</sub>]<sup>9-</sup>, tethered with an anthracene photosensitizer was prepared and used as catalyst for CO<sub>2</sub> reduction. The polyoxometalate-photosensitizer hybrid complex, obtained by covalent attachment of the sensitizer to only one face of the planar polyoxometalate, was characterized by NMR, IR and mass spectroscopy. Cyclic voltammetry measurements show a catalytic response for the reduction of carbon dioxide, thereby suggesting catalysis at the manganese site on the open face of the polyoxometalate. Controlled potentiometric electrolysis showed the reduction of CO<sub>2</sub> to CO with a TOF of ~15 sec<sup>-1</sup>. Further photochemical reactions showed that the polyoxometalate-anthracene hybrid complex was active for the reduction of CO<sub>2</sub> to yield formic acid and/or CO in varying amounts dependent on the reducing agent used. Control experiments showed that the attachment of the photosensitizer to [MnMo<sub>6</sub>O<sub>24</sub>]<sup>9-</sup> is necessary for photocatalysis.</p><div><br></div>

Investigation of Polyoxometalate-(Poly)pyrrole Heterogeneous Nanostructures as Cathodes for Rechargeable Magnesium-Ion Batteries

2018 ◽  
Author(s):  
Hakeem K. Henry ◽  
Sang Bok Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Active Material ◽  
Conductive Polymer ◽  
Current Collector ◽  
Constant Current ◽  
Anodized Aluminum ◽  
Transmission Electron ◽  
Pyrrole Monomer

The PMo<sub>12</sub>-PPy heterogeneous cathode was synthesized electrochemically. In doing so, the PMo<sub>12</sub> redox-active material was impregnated throughout the conductive polymer matrix of the poly(pyrrole) nanowires. All chemicals and reagents used were purchased from Sigma-Aldrich. Anodized aluminum oxide (AAO) purchased from Whatman served as the porous hard template for nanowire deposition. A thin layer of gold of approximately 200nm was sputtered onto the disordered side of the AAO membrane to serve as the current collector. Copper tape was connected to the sputtered gold for contact and the device was sealed in parafilm with heat with an exposed area of 0.32 cm<sup>2</sup> to serve as the electroactive area for deposition. All electrochemical synthesis and experiments were conducted using a Bio-Logic MPG2 potentiostat. The deposition was carried out using a 3-electrode beaker cell setup with a solution of acetonitrile containing 5mM and 14mM of the phosphomolybdic acid and pyrrole monomer, respectively. The synthesis was achieved using chronoamperometry to apply a constant voltage of 0.8V vs. Ag/AgCl (BASi) to oxidatively polymerize the pyrrole monomer to poly(pyrrole). To prevent the POM from chemically polymerizing the pyrrole, an injection method was used in which the pyrrole monomer was added to the POM solution only after the deposition voltage had already been applied. The deposition was well controlled by limiting the amount of charge transferred to 300mC. Following deposition, the AAO template was removed by soaking in 3M sodium hydroxide (NaOH) for 20 minutes and rinsed several times with water. After synthesis, all cathodes underwent electrochemical testing to determine their performance using cyclic voltammetry and constant current charge-discharge cycling in 0.1 M Mg(ClO<sub>4</sub>)<sub>2</sub>/PC electrolyte. The cathodes were further characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and x-ray photoelectron spectroscopy (XPS).

Graphene Supported Tungsten Carbide as Catalyst for Electrochemical Reduction of CO2

2019 ◽  
Author(s):  
Sahithi Ananthaneni ◽  
Rees Rankin
Keyword(s):  
Tungsten Carbide ◽  
Electrochemical Reduction ◽  
Low Cost ◽  
Co2 Reduction ◽  
Platinum Group Metal ◽  
Reduction Reaction ◽  
Metal Carbides ◽  
Depth Study ◽  
Reduction Of Co2 ◽  
Co2 Reduction Reaction

<div>Electrochemical reduction of CO2 to useful chemical and fuels in an energy efficient way is currently an expensive and inefficient process. Recently, low-cost transition metal-carbides (TMCs) are proven to exhibit similar electronic structure similarities to Platinum-Group-Metal (PGM) catalysts and hence can be good substitutes for some important reduction reactions. In this work, we test graphenesupported WC (Tungsten Carbide) nanocluster as an electrocatalyst for the CO2 reduction reaction. Specifically, we perform DFT studies to understand various possible reaction mechanisms and determine the lowest thermodynamic energy landscape of CO2 reduction to various products such as CO, HCOOH, CH3OH, and CH4. This in-depth study of reaction energetics could lead to improvements and develop more efficient electrocatalysts for CO2 reduction.<br></div>

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