Environmental photochemistry on surfaces. Charge injection from excited fulvic acid into semiconductor colloids

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00034a013· OSTI ID:6718477

Vinodgopal, K ^[1]; Kamat, P V ^[2]

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1. Indiana Univ. Northwest, Gary, IN (United States)
2. Univ. of Notre Dame, Notre Dame, IN (United States)

The ability of naturally occurring fulvic acid to sensitize a large band-gap semiconductor, colloidal ZnO, has been investigated by fluorescence emission and transient absorption measurements in a mixed alcohol-water system. The fulvic acid strongly adsorbs on the semiconductor particles, with an apparent association constant of 12000 [+-] 500 M[sup [minus]1]. The net charge-transfer efficiency as determined by the fluorescence quenching of reference Suwanee River fulvic acid (SFA) by ZnO was 73%. The laser flash photolysis experiments that elucidate the mechanistic details of the charge injection from excited fulvic acid into the conduction band of ZnO (k[sub et] = 6.8 x 10[sup 8] s[sup [minus]1]) are described. 28 refs., 5 figs.

• OSTI ID: 6718477
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 26:10; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHALCOGENIDES
CHEMICAL REACTIONS
FULVIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSENSITIVITY
SENSITIVITY
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES