Quantum Yields of Silver Ion Reduction on TiO2 and ZnO Single Crystals.
Abstract
Photogenerated charge carriers near a semiconductor or insulator solid surface may interact with adsorbed ions on the solid surface and result in a change in the charge-state of the adsorbate. The interaction of nonequilibrium charge carriers with adsorbed species at a solid-liquid interface is a typical phenomenon and occurs in many systems. The work has been concentrated on two such systems, silver ion on zinc oxide and on titanium dioxide. Direct kinetic measurements of the rate of metallic silver formation on the substrate surfaces have involved the analysis of silver by a combination method involving spectral transmission and electrochemical and atomic absorption techniques. The quantum efficiency of the continuous silver deposition process is independent of the exciting light intensity when the wavelength of the maximum excitation is 365 nm. The measured yield does depend, however, on solution silver ion concentration; the yield increases with increasing Ag(+) concentration reaching a maximum at high concentrations. A mechanism that describes the photodeposition reaction is presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 15, 1971
- Accession Number
- AD0732285
Entities
People
- H. K. Alan Kan
- John R. Shepherd
- Paul D. Fleischauer
Organizations
- The Aerospace Corporation