Hydrated electrons are formed in the illumination of a CdS colloid and of ZnS/CdS co-colloids with a 347.2-nm laser flash. The yield is increased by excess sulfide anions. In the presence of 2 × 10-3 M Na2S, the quantum yield is 0.15 hydrated electrons per absorbed photon. The photoelectron emission from the colloids shows the intensity dependence of a monophotonic process. A mechanism is proposed in which the storage of a huge number of electrons for a short time after scavenging of positive holes by sulfide anions plays an important role. The accompanying cathodic potential changes enable part of the electrons to migrate from the colloidal particles into the aqueous phase.
ASJC Scopus subject areas
- Engineering (all)
- Physical and Theoretical Chemistry