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Titolo:
Silver electrocrystallization onto carbon electrodes with different surface morphology: Active sites vs surface features
Autore:
Miranda-Hernandez, M; Gonzalez, I; Batina, N;
Indirizzi:
Univ Autonoma Metropolitana Iztapalapa, Dpto Quim, Area Electroquim, Mexico City 09340, DF, Mexico Univ Autonoma Metropolitana Iztapalapa Mexico City DF Mexico 09340 Mexico Inst Mexicano Petr, Coordinac Simulac Mol Area Mat & Corros, Mexico City 07730, DF, Mexico Inst Mexicano Petr Mexico City DF Mexico 07730 ico City 07730, DF, Mexico
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY B
fascicolo: 19, volume: 105, anno: 2001,
pagine: 4214 - 4223
SICI:
1520-6106(20010517)105:19<4214:SEOCEW>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
SCANNING-TUNNELING-MICROSCOPY; GLASSY-CARBON; VITREOUS CARBON; GRAPHITE-ELECTRODES; ELECTROCHEMICAL-BEHAVIOR; TRANSFER KINETICS; NUCLEATION; LEAD; DEPOSITION; CAPACITANCE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
51
Recensione:
Indirizzi per estratti:
Indirizzo: Batina, N Univ Autonoma Metropolitana Iztapalapa, Dpto Quim, Area Electroquim, AP 55-534, Mexico City 09340, DF, Mexico Univ Autonoma Metropolitana Iztapalapa AP 55-534 Mexico City DF Mexico 09340
Citazione:
M. Miranda-Hernandez et al., "Silver electrocrystallization onto carbon electrodes with different surface morphology: Active sites vs surface features", J PHYS CH B, 105(19), 2001, pp. 4214-4223

Abstract

The influence of the electrode surface quality and surface morphology on the silver electrocrystallization process onto a carbon substrate from 10(-2) M Ag(NH3)(2)(+)/1.6 M NH3-, 1 M KNO3 (pH = 11) electrolyte solution was studied. Three substrates with different types of surface morphology and surface roughness were used: highly oriented pyrolitic graphite (HOPG), mechanically polished vitreous carbon (MPVC), and fractured vitreous carbon (FVC). Before the silver deposition process, the electrode surface was examined and characterized by means of Atomic Force Microscopy (AFM) analysis. Evaluation of the kinetic parameters of the silver nucleation and the growth behavior, as well as other characteristics of the silver electrocrystallization process onto carbon substrates, were based on cyclic voltammetry and chronoamperometric measurements. Cyclic voltammetry data also show that silver deposition efficiency is proportional to the increase of electrode surface roughness (from HOPG, via MPVC to FVC). The silver bulk deposition process on all three carbon substrates was characterized as 3D nucleation and diffusion-controlled growth. However, this process proceeds with different overpotentials on different substrates: the lowest for HOPG and the highest for MPVC electrode surface. The major electrocrystallization parameters, such as nucleation rate, number of active sites, and number of fanned silver nuclei, strictly related to the electrode surface conditions, seem to not follow the same trends as the cyclic voltammetry data. It is clearly indicated in the nonlinear relationship between number of active sites and the surfacefeatures (recognized in AFM images). As pointed out in the discussion, it opens new questions regarding the nature of the active sites for depositionon the electrode surface and their identification by microscopic techniques.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/09/20 alle ore 23:15:31