Photochemistry of semiconductor colloids. 22. Electron injection from illuminated CdS into attached TiO/sub 2/ and ZnO particles

Journal Article · Wed Oct 28 04:00:00 EST 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00256a012· OSTI ID:5522067

Spanhel, L; Weller, H; Henglein, A

Colloidal solutions of CdS containing colloidal TiO/sub 2/ or ZnO were illuminated with visible light. The fluorescence of CdS (decay time approx. 50 ns) was quenched by TiO/sub 2/, several TiO/sub 2/ particles being required per CdS particle. The rate of photoanodic corrosion in aerated solution was drastically increased in the presence of TiO/sub 2/. In deaerated CdS solutions containing methanol and Cd/sup 2 +/ ions, cadmium metal was formed when TiO/sub 2/ was present. Methyl viologen was reduced with a quantum yield of close to one, while it reacted about ten times more slowly in the absence of TiO/sub 2/. These effects are explained in terms of improved charge separation by rapid electron injection from illuminated CdS into the conduction band of attached TiO/sub 2/ particles. Electron injection into ZnO was less efficient and occurred only in the case of Q-CdS particles (very small particles having a greater band gap). The injected electrons caused a blue shift of the absorption threshold of ZnO.

• Research Organization: Hahn-Meitner-Institut Berlin, West Germany
• OSTI ID: 5522067
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:22; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CADMIUM COMPOUNDS
CADMIUM SULFIDES
CHALCOGENIDES
CHEMISTRY
COLLOIDS
DATA
DISPERSIONS
EFFICIENCY
EXPERIMENTAL DATA
INFORMATION
INORGANIC PHOSPHORS
MATERIALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOSPHORS
PHOTOCHEMISTRY
QUANTUM EFFICIENCY
SEMICONDUCTOR MATERIALS
SULFIDES
SULFUR COMPOUNDS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
ZINC COMPOUNDS
ZINC OXIDES