Growth of silver particles in aqueous solution: Long-lived magic clusters and ionic strength effects

Journal Article · Thu Jan 14 00:00:00 EST 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100104a013· OSTI ID:6341180

Ershov, B G; Janata, E; Henglein, A ^[1]

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1. Hahn-Meitner-Institut Berlin GmbH (Germany)

Pulse radiolytic reduction of silver ions leads to an oligomeric cluster absorbing at 295 nm and most intensely and sharply at 325 nm. The cluster has a half-life of >5 min in scrupulously clean reaction vessels. During its decay, larger metallic particles absorbing around 380 nm are produced. The cluster is long-lived only in the presence of excess Ag[sup +] ions. A second cluster absorbing at 345 nm is also formed during the oxidation. Tetranitromethane reacts with the cluster to form the nitroform anion, from which the absorption coefficient per Ag atom is calculated to be 2 [times] 10[sup 4] M[sup [minus]1] cm[sup [minus]1]. The formation of the cluster is accelerated by NaClO[sub 4]; the Bjerrum-Broenstedt evaluation of this effect shows that a precursor of the cluster carries three elementary charges. The formation of larger metallic particles is even more strongly accelerated by NaClO[sub 4]. In the presence of 10[sup [minus]4]M Na[sub 2]SO[sub 4], the formation and decay of the cluster occur practically at the diffusion-controlled rate. From the rate of the buildup under these conditions, it is estimated that the cluster contains eight reduced silver atoms. The effects of ionic strength on the growth of the clusters and metallic particles are compared to the salt effects in slow and fast coagulation of colloids. 14 refs., 8 figs.

• OSTI ID: 6341180
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 97:2; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
PARTICLES
GROWTH
SILVER COMPOUNDS
SYNTHESIS
CHARGES
CHEMICAL REACTION KINETICS
COLLOIDS
DIFFUSION
HALF-LIFE
OXIDATION
PRECURSOR
RADIOLYSIS
REDUCTION
SILVER IONS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
DISPERSIONS
IONS
ISOTOPES
KINETICS
RADIATION EFFECTS
RADIOISOTOPES
REACTION KINETICS
TRANSITION ELEMENT COMPOUNDS
YEARS LIVING RADIOISOTOPES
400201* - Chemical & Physicochemical Properties
400600 - Radiation Chemistry