H2O2-mediated oxidation of zero-valent silver and resultant interactions among silver nanoparticles, silver ions, and reactive oxygen species
The H(2)O(2)-mediated oxidation of silver nanoparticles (AgNPs) over a range of pH (3.0-14.0) is investigated here, and an electron charging-discharging model capable of describing the experimental results obtained is developed. AgNPs initially react with H(2)O(2) to form Ag(+) and superoxide, with...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 28(2012), 27 vom: 10. Juli, Seite 10266-75 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
|
| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Cations, Monovalent Citrates Reactive Oxygen Species trisodium citrate Silver 3M4G523W1G Hydrogen Peroxide BBX060AN9V mehr... |
| Zusammenfassung: | The H(2)O(2)-mediated oxidation of silver nanoparticles (AgNPs) over a range of pH (3.0-14.0) is investigated here, and an electron charging-discharging model capable of describing the experimental results obtained is developed. AgNPs initially react with H(2)O(2) to form Ag(+) and superoxide, with these products subsequently reacting to reform AgNPs (in-situ-formed AgNPs) via an electron charging-discharging mechanism. Our experimental results show that the AgNP reactivity toward H(2)O(2) varies significantly with pH, with the variation at high pH (>10) due particularly to the differences in the reactivity of H(2)O(2) and its conjugate base HO(2)(-) with AgNPs whereas at lower pH (3-10) the pH dependence of H(2)O(2) decay is accounted for, at least in part, by the pH dependence of the rate of superoxide disproportionation. Our results further demonstrate that the in-situ-formed AgNPs resulting from the superoxide-mediated reduction of Ag(+) have a different size and reactivity compared to those of the citrate-stabilized particles initially present. The turnover frequency for AgNPs varies significantly with pH and is as high as 1776.0 min(-1) at pH 11.0, reducing to 144.2 min(-1) at pH 10.0 and 3.2 min(-1) at pH 3.0 |
|---|---|
| Beschreibung: | Date Completed 01.11.2012 Date Revised 21.11.2013 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la300929g |