Optical and chemical observations on gold-mercury nanoparticles in aqueous solution
The {gamma}-radiolytic reduction of Hg{sup 2+} in aqueous solution in the presence of 0.3 M 2-propanol first leads to Hg{sub 2}{sup 2+} ({epsilon}{sub 237 nm} = 3.2 x 10{sup 4} M{sup {minus}1} cm{sup {minus}1}), and later to colloidal mercury. When the reduction is carried out in the presence of colloidal gold nanoparticles, Hg{sub 2}{sup 2+} does not appear as an intermediate, and Hg{sub 2}{sup 2+} formed in the absence of gold does not react with added gold colloid. These effects are understood in terms of the reaction of a precursor, Hg{sup +}, with the gold particles. The optical absorption spectra of the resulting mercury containing gold particles are reported for various Au/Hg ratios. The plasmon absorption band of gold is blue-shifted and damped, and a broad absorption band develops around 360 nm with increasing mercury content. The mercury of the composite particles is slowly reoxidized upon exposure of the solution to air. Excess Hg{sup 2+} ions in solution extract adsorbed mercury in the form of Hg{sub 2}{sup 2+}. Both the absorption spectra and electron micrographs of the gold particles are interpreted by a rather weak penetration of mercury into the particles and formation of a rather labile mercury layer around them.
- Research Organization:
- Univ. of Notre Dame, IN (US)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 20075912
- Journal Information:
- Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Vol. 104, Issue 21; Other Information: PBD: 1 Jun 2000; ISSN 1089-5647
- Country of Publication:
- United States
- Language:
- English
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