title: Oxidative dissolution of silver nanoparticles: A new theoretical approach.
abstract: A general model of an oxidative dissolution of silver particle suspensions was developed that rigorously considers the bulk and surface solute transport. A two-step surface reaction scheme was proposed that comprises the formation of the silver oxide phase by direct oxidation and the acidic dissolution of this phase leading to silver ion release. By considering this, a complete set of equations is formulated describing oxygen and silver ion transport to and from particles' surfaces. These equations are solved in some limiting cases of nanoparticle dissolution in dilute suspensions. The obtained kinetic equations were used for the interpretation of experimental data pertinent to the dissolution kinetics of citrate-stabilized silver nanoparticles. In these kinetic measurements the role of pH and bulk suspension concentration was quantitatively evaluated by using the atomic absorption spectrometry (AAS). It was shown that the theoretical model adequately reflects the main features of the experimental results, especially the significant increase in the dissolution rate for lower pH. Also the presence of two kinetic regimes was quantitatively explained in terms of the decrease in the coverage of the fast dissolving oxide layer. The overall silver dissolution rate constants characterizing these two regimes were determined.
authors.affiliation: Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland. Electronic address: ncadamcz@cyf-kr.edu.pl.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Adamczyk
authors.affiliation: Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland. Electronic address: ncocwiej@cyf-kr.edu.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Oćwieja
authors.affiliation: Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Cracow, Poland. Electronic address: mrowiec@chemia.uj.edu.pl.
authors.forename: Halina
authors.initials: H
authors.lastname: Mrowiec
authors.affiliation: Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Cracow, Poland. Electronic address: walas@chemia.uj.edu.pl.
authors.forename: Stanisław
authors.initials: S
authors.lastname: Walas
authors.affiliation: Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland.
authors.forename: Dawid
authors.initials: D
authors.lastname: Lupa
keywords: Kinetics of silver nanoparticle dissolution; Oxidative dissolution of silver nanoparticles; Silver ion release; Silver nanoparticle dissolution; Theoretical model of silver nanoparticle dissolution