The anodic stripping voltammetry of nanoparticles: electrochemical evidence for the surface agglomeration of silver nanoparticles (original) (raw)
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Cyclic Voltammetry of Silver Nanoparticles on Platinum, Gold and Glassy Carbon Electrodes
Revista de Chimie -Bucharest- Original Edition-
The electrochemical behaviour of silver nanoparticles stabilized with polyvinylpyrrolidone is studied in aqueous 0.1M KNO 3 on platinum, gold and glassy carbon electrodes. The silver nanoparticles are loaded through adsorption from solution onto the electrode surface and cyclic voltammetry experiments are performed onto the loaded electrodes. The data show that the electrode coverage is rather low for all studied electrodes; the interaction between silver nanoparticles and the electrode increases in the order: glassy carbon < platinum < gold. The oxidation of silver nanoparticles leads to a decrease in the particle loading onto the electrode, as expected for a stripping process.
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Electrochemical mediated synthesis of silver nanoparticles in solution
Russian Journal of Electrochemistry, 2015
Methyl viologen MV 2+ and tetraviologen calix[4]resorcinol MVCA with n pentyl substitu ents in the resorcinol rings at potentials of MV 2+ /MV •+ and MVCA /MVCA redox couples proved to be effective mediators of the electrochemical reduction of Ag + ions in DMF/0.1 M Bu 4 NPF 6. The poten tiostatic nondiaphragm electrolysis at controlled mediator reduction potentials at room temperature using an Ag anode as an in situ supplier of Ag + led to the formation of metallic silver nanoparticles in solution. The only resulting effect of electrolysis was the quantitative transfer of the metal anode into the metal nanoparti cles in solution. In the case of MV 2+ , the nanoparticles aggregated into larger particles. MVCA serves not only as a mediator, but also, to some extent, as a stabilizer of silver nanoparticles and can be recorded by a set of experimental methods.
Journal of Electroanalytical Chemistry, 1999
Silver voltammetric anodic stripping from stabilized rough platinum electrodes in 1 M H 2 SO 4 + c o Ag 2 SO 4 (5× 10 − 4 M5 c o 510 − 3 M) and 1 M H 2 SO 4 aqueous solutions, at 298 K, was investigated. The topography of these electrodes was determined by scanning tunneling microscopy (STM). The roughness factor, R, was varied from 10 to 71. The analysis of STM images showed that the rough structure consists of an array of nm-sized protrusions and voids as a columnar structured surface. For each value of R, the average size and volume of voids were determined. The voltammetric features of silver anodic stripping depend on R and the electrodeposited silver charge, Q Ag. The value of Q Ag (vs), the saturation value of Q Ag for voids, was estimated. The anodic stripping of underpotential deposited silver occurs in the potential range where oxygen electroadsorption on platinum takes place. By using data derived from STM imaging and equations that have been derived for the voltammetric anodic stripping reactions, in which the reactant is confined to nm-sized voids, the voltammetric behaviour of the system can be reproduced reasonably.
Electrochemical Synthesis of Silver and Gold Nanoparticles
ECS Transactions, 2007
Silver and gold nanoparticles were prepared by electrodeposition from sulfite based solutions as a possible alternative to the standard chemistry usually proposed in the literature for electrochemical deposition of silver and gold nanoparticles. The voltammetric behavior of the electrolytes is studied at glassy carbon and titanium surface, showing that kinetic control plays a role in the discharge of the sulfite complex of either silver or gold. The formation of particles on titanium substrate and their morphological features are examined, changing the deposition conditions, pulse potential and duration or potential scan rate. Remarkable differences in the formation of Ag and Au particles on the titanium substrate are highlighted: growth and aggregation characterize the formation of Ag particles; on the contrary, Au particles are deposited with high nucleation density and uniform size distribution, though the particle dimension is rather on the mesoscale than in the nanoscale dimension. copyright The Electrochemical Society 67 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.175.55.34 Downloaded on 2015-03-28 to IP ECS Transactions, 2 (20) 67-77 (2007) ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.175.55.34 Downloaded on 2015-03-28 to IP
Journal of Electroanalytical Chemistry, 2018
Silver was electrodeposited onto glassy carbon electrode from 0.1 mM AgClO 4 acetonitrile solution containing 0.1 M LiClO 4. The electrochemical deposition was carried out at constant potential of −0.5 V vs. SCE. The surface morphology was studied by scanning electron microscopy and the average particle size was determined to be 45 nm to 90 nm when increasing the deposition time from 10 s to 300 s. The rotating disk electrode (RDE) method was employed for oxygen reduction studies in 0.1 M KOH solution. It was determined that the final product for the reaction is water and the rate-determining step is the slow transfer of the first electron to O 2 molecule. The specific activities (SA) and mass activities (MA) were calculated from the RDE results and the latter was independent of the deposition time. The method used to determine electroactive surface area of Ag influenced substantially the determination of SA values.
Journal of Solid State Electrochemistry, 2012
A voltammetric method has been tested for the investigation of the kinetics of formation of silver nanoparticles in two systems: (a) silver(I) triflourineacetate, methylcellosolve, butyl acetate, toluene and methyl methacrylate with methacrylic acid copolymer; and (b) silver nitrate, sodium citrate, poly-N-vinyl-2-pirrolydone, sodium borohydride. It could be established for the first system that the formation rate of metal nanoparticles from silver triflourineacetate solutions depends on the dielectric constant and complexing ability of the solvent. The formation of silver particles proceeds faster in methylcellosolve than in other solvents. The butyl acetate addition to the solution contributes to the complex stability of methylcellosolve with silver triflourineacetate and decelerates the formation process of particles. It could be shown that nitrogen purging of solutions containing poly-N-vinyl-2-pirrolydone affects the silver-ion concentration in the first stage of synthesis and accelerates the formation process of nanoparticles for the second system. The spherical silver nanoparticles which are formed at the first stage of the synthesis are destroyed after starting the UV-irradiation. Then new silver nanoparticles (triangular prisms) are formed.