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

Journal Article · Wed Oct 28 00:00:00 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), Vol. 109:22
• Country of Publication: United States
• Language: English

Related Subjects

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