scholarly journals Influence of supporting electrolyte on electrochemical formation of copper nanoparticles and their electrocatalytic properties

2021 ◽  
Author(s):  
Silvana García ◽  
Noelia Zurita
Keyword(s):  
Copper Nanoparticles ◽  
Electrolyte Solution ◽  
Particle Density ◽  
Supporting Electrolyte ◽  
Pyrolytic Graphite ◽  
Electrolyte Solutions ◽  
Reduction Reaction ◽  
Three Solutions ◽  
Sem Images ◽  
Size Dispersion

Comparative analysis of copper nanoparticles (CuNPs) obtained by electrodeposition on highly oriented pyrolytic graphite (HOPG) substrates from different supporting electrolytes containing sulphate anions, was performed. Voltammetric results indicated that Cu electrodeposition follows a diffusion-controlled nucleation and crystal growth model for three solutions studied (Na2SO4, H2SO4 and Na2SO4+H2SO4). Na2SO4 solution was found to be most effective because the copper reduction occurs at most positive potential value, reaching the highest current density. Analysis of potentiostatic current transients revealed that the process can be described predominantly by a model involving 3D-progressive nucleation mechanism, which was corroborated by scanning electron microscopy (SEM) analysis. SEM images showed high density of hemispherical shaped Cu particles of different sizes (mostly between 80-150 nm), randomly distributed on the HOPG surface for Na2SO4 electrolyte solution. In the presence of H2SO4, the size dispersion decreased, resulting in particles with greater diameters (up to 339 nm). The use of electrolyte solution with Na2SO4+H2SO4 revealed lower particle density with a considerable crystal size dispersion, where very small crystallites are prevailing. Cyclic voltammetry was used to evaluate qualitatively the catalytic activity of CuNPs deposited from three electrolyte solutions towards the nitrate reduction reaction. An enhanced catalytic effect was obtained when copper particles were prepared from either Na2SO4 or H2SO4 supporting electrolytes.

scholarly journals Enteral electrolyte solutions with different osmolarities administered in a continuous flow in newborn calves

2017 ◽  
Vol 47 (5) ◽  
Author(s):  
José Dantas Ribeiro Filho ◽  
Waleska de Melo Ferreira Dantas ◽  
Antônio de Pádua Lima ◽  
Rinaldo Batista Viana ◽  
Micheline Ozana da Silva ◽  
...  
Keyword(s):  
Electrolyte Solution ◽  
Continuous Flow ◽  
Sodium Acetate ◽  
Electrolyte Solutions ◽  
Plasma Sodium ◽  
Holstein Cattle ◽  
Three Solutions ◽  
Serum Osmolarity ◽  
Water Solutions ◽  
Newborn Calves

ABSTRACT: This study compared the effects of enteral electrolyte solutions with different osmolarities in Holstein cattle. Eighteen newborn calves were evenly divided into three groups and administered the following treatments: hypotonic electrolyte solution (ESHYPO) containing 4g NaCl, 0.5g KCl, 1g sodium acetate, and 7.5g dextrose diluted in 1,000mL water; isotonic electrolyte solution (ESISO) containing 5g NaCl, 1g KCl, 2g sodium acetate, and 10g dextrose diluted in 1,000mL water; and hypertonic electrolyte solution (ESHYPER) containing 6g NaCl, 1g KCl, 3g sodium acetate, and 15g dextrose diluted in 1,000mL water. Solutions were administered at a rate of 15mL kg-1hr-1 for 12 hours in a continuous flow. All three solutions increased the concentration of plasma sodium, but ESHYPO did not alter the serum osmolarity. Both ESISO and ESHYPO resulted in an increase in volemia.

Promoting Nitrogen Electroreduction to Ammonia with Bismuth Nanocrystals and Potassium Cations in Water

2020 ◽  
Author(s):  
Jaecheol Choi ◽  
Hoang-Long Du ◽  
Manjunath Chatti ◽  
Bryan H. R. Suryanto ◽  
Alexandr Simonov ◽  
...  
Keyword(s):  
Electrocatalytic Activity ◽  
Aqueous Electrolyte ◽  
Electrolyte Solutions ◽  
Reduction Reaction ◽  
Nitrogen Reduction ◽  
Aqueous Electrolyte Solutions

We demonstrate that bismuth exhibits no measurable electrocatalytic activity for the nitrogen reduction reaction to ammonia in aqueous electrolyte solutions, contrary to several recent reports on the highly impressive rates of Bi-catalysed electrosynthesis of NH<sub>3</sub> from N<sub>2</sub>.

Surface charging parameters of charged particles in symmetrical electrolyte solutions

2020 ◽  
Vol 22 (35) ◽  
pp. 20123-20142
Author(s):  
Hadi Saboorian-Jooybari ◽  
Zhangxin Chen
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Electrolyte Solution ◽  
Surface Charge Density ◽  
Potential Surface ◽  
Research Work ◽  
Charged Particles ◽  
Electrolyte Solutions ◽  
Surface Charging ◽  
Curvature Dependence

This research work is directed at development of accurate physics-based formulas for quantification of curvature-dependence of surface potential, surface charge density, and total surface charge for cylindrical and spherical charged particles immersed in a symmetrical electrolyte solution.

Polarography of nickel in concentrated chloride media

1966 ◽  
Vol 19 (8) ◽  
pp. 1343 ◽  
Author(s):  
TM Florence
Keyword(s):  
Ionic Strength ◽  
Graphite Electrode ◽  
Supporting Electrolyte ◽  
Anhydrous Methanol ◽  
Pyrolytic Graphite ◽  
Hydration Number ◽  
Mercury Electrode ◽  
Specific Adsorption ◽  
Dropping Mercury Electrode ◽  
Pyrolytic Graphite Electrode

In concentrated chloride media, nickel is reduced at far more positive potentials than in dilute solutions. The positive shift in half-wave potential increases as the ionic strength is raised, and is also greater when the cation of the supporting electrolyte has a high hydration number. Evidence is presented to show that the reduction in overpotential is due to the formation of a nickel chloride complex, [Ni(H2O)5Cl]+, which has a stoicheiometric stability constant of 0.094 � 0.009 at an ionic strength of 10.0. Spectrophotometric results show that this nickel species is not formed in low ionic strength solutions. In anhydrous methanol saturated with lithium chloride, nickel is present as the tetrachloro complex, [NiCl,]2-, which has similar polarographic behaviour to the monochloro complex. Current-potential curves recorded at a rotated pyrolytic graphite electrode enabled the behaviour of nickel to be studied in the absence of specific adsorption of the chloride ion. Nickel is reduced at more positive potentials at a dropping mercury electrode than at the pyrolytic graphite electrode, and the results indicate that this difference is due to specific adsorption of chloride on the mercury electrode.

Dependence on treatment ion energy of nitrogen plasma for oxygen reduction reaction of high ordered pyrolytic graphite

2018 ◽  
Vol 57 (12) ◽  
pp. 125504
Author(s):  
Yuichi Hashimoto ◽  
Hsin-Hui Huang ◽  
Masamichi Yoshimura ◽  
Masanori Hara ◽  
Tamio Hara ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Pyrolytic Graphite ◽  
Nitrogen Plasma ◽  
Reduction Reaction ◽  
Ion Energy

The Effect of Preparation Temperature of Electrolytes on Undoped and Ag-Doped TiO2 Nanotube Structures

2016 ◽  
Vol 860 ◽  
pp. 7-11 ◽  
Author(s):  
Somkuan Photharin ◽  
Buagun Samran ◽  
Rinnatha Vongwatthaporn ◽  
Narongsak Kodtharin ◽  
Ramida Chaiyarat ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrolyte Solution ◽  
Pure Titanium ◽  
Silver Ions ◽  
Ammonium Fluoride ◽  
Electrolyte Solutions ◽  
Nanotube Arrays ◽  
X Ray Diffraction ◽  
Preparation Temperature ◽  
X Ray

In this work, we present the effect of preparation temperature of electrolytes for fabricating undoped and silver (Ag) doped titanium dioxide (TiO2) nanotubes by the electrochemical anodic oxidation of pure titanium sheets in electrolytes, mixtures of ethylene glycol (EG), ammonium fluoride (NH4F) and deionized water, that contain with different of silver ions. Heat treatment of electrolytes was carried out at 100 °C during preparation process. The morphology and structure of prepared nanotubes were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The structures of TiO2 nanotubes obtained from heat treatment and non-heat treatment of electrolyte solutions and adding silver ions in electrolyte solution are similar. The nanotubes appear in arrays and the diameters of nanotubes were about 92 nm for non-heat treatment electrolyte solution and undoped TiO2 and about 102 nm for heat treatment electrolyte solution and all Ag-doped TiO2 nanotube arrays. When the concentration of silver nitrate (AgNO3) increases, the TiO2 nanotube arrays cracked and are not well arranged.

Photoluminescence of Hybrid Structure Base in ZnO@SiO2 Core-Shell Nanoparticles inside Porous Silicon

2019 ◽  
Vol 286 ◽  
pp. 40-48
Author(s):  
Xairo Leon ◽  
Edith Osorio ◽  
Rene Pérez-Cuapio ◽  
Carlos Bueno ◽  
Mauricio Pacio ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Luminescent Properties ◽  
Electrolyte Solutions ◽  
Hybrid Structure ◽  
Colloidal Synthesis ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Sem Images ◽  
Mesoporous Silicon ◽  
The Core

In this work, core-shell ZnO@SiO2nanoparticles (NPs) were infiltrated into a macro/meso-porous silicon (PS) structure, to study its luminescent properties. The core-shell ZnO@SiO2NPs were obtained by colloidal synthesis. The core-shell ZnO@SiO2NP was 5 nm in diameter. The macro/meso-PS structure was made in two steps: we obtained the macroporous silicon (macro-PS) layer fist and the mesoporous silicon (meso-PS) layer second. This process was conducted using different electrolyte solutions, and the change of electrolyte led to a decrease in the special charge region over the wall macro-PS layer; this allowed the building of the meso-PS layers on the walls and the bottom of the macro-PS layer. The SEM results show the cross-section of the macro/meso-PS structure with and without core-shell ZnO@SiO2NPs. These SEM images show that the core-shell ZnO@SiO2NPs that infiltrated into macro/meso-PS structure were more efficiently bonded over all the porous walls. The core-shell ZnO@SiO2PL interacted with the macro/meso-PS structure, modifying its PL intensity and controlling a shift toward a lower wavelength.

Polypyrrole Actuator Operating Characteristicsin Electrolyte Solution Mixed with Methanol

2013 ◽  
Vol 300-301 ◽  
pp. 1352-1355 ◽  
Author(s):  
Futo Tsumuji ◽  
Daiki Hoshino ◽  
Shou Ogihara ◽  
Zong Fan Duan ◽  
Yutaro Suzuki ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Electrolyte Solution ◽  
Marked Improvement ◽  
Electrolyte Solutions ◽  
Rapid Decrease ◽  
The Other ◽  
Other Hand ◽  
Deformation Behaviors

In this work, a PPy actuator was fabricated by galvanostatic electropolymerization. The electrochemical deformation behaviors of the PPy actuator were investigated in aqueous solutions of an electrolyte, lithium bis(trifluoromethanesulphonyl)imide (LiTFSI), containing different concentrations of methanol. Marked improvement of the actuating strain of approximately 9% was achieved when the actuator was driven by a potential between –1 and 1 V in the LiTFSI electrolyte containing 40 to 50% of methanol under a load stress of 0. 3 MPa. On the other hand, the actuator functioned in the electrolyte solutions containing more than 60% of methanol showed rapid decrease of the actuating strain and the electrochemical creep after repeated actuations. Possible mechanisms for these behaviors were discussed.

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