Photochemistry and radiation chemistry of semiconductor colloids. 27. Preparation of colloidal PbO sub 2 various electron-transfer processes

Journal Article · Thu Mar 23 04:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100343a015· OSTI ID:5143215

Kumar, A; Henglein, A; Weller, H ^[1]

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1. Hahn-Meitner-Institut, Berlin (Germany, F.R.)

Colloidal PbO{sub 2} (mean particle size 3.6 nm) was prepared by radiolytic oxidation of lead ions in alkaline solution, sodium hexametaphosphate acting as stabilizer. The PbO{sub 2} particles dissolved cathodically upon attack by hydroxy alkyl radicals, which is explained by electron transfer from the radicals to the colloidal particles. This transfer is accompanied by a blue-shift in the absorption spectrum of PbO{sub 2} (bleaching between 300 and 600 nm) and a weak absorption at long wavelengths (600-730 nm). One colloidal particle can accept a large number of electrons to yield Pb(II) centers. Further reduction by radicals leads to Pb(I) which, however, rapidly conproportionates with Pb(IV) in the colloidal particles. Under illumination PbO{sub 2} particles are more oxidizing than in the dark. Bleaching and absorption signals were also observed in the laser flash photolysis of colloidal PbO{sub 2} solutions; the rapid decay of the signals indicated that the generated charge carriers were very short-lived.

• OSTI ID: 5143215
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:6; ISSN JPCHA; 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
400500* -- Photochemistry
400600 -- Radiation Chemistry
ALCOHOLS
ARGON
CHALCOGENIDES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COLLOIDS
DATA
DECOMPOSITION
DISPERSIONS
EFFICIENCY
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HYDROXY COMPOUNDS
INFORMATION
LEAD COMPOUNDS
LEAD OXIDES
MATERIALS
METHANOL
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
RARE GASES
SEMICONDUCTOR MATERIALS