T. Uchihara et al., Stability of colloidal solutions containing various surface-modified cadmium sulfide particles under stationary illumination, J PHOTOCH A, 130(1), 2000, pp. 63-69
Citations number
28
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
Stability of the various colloidal solutions containing CdS particles with
the surface modified by thiols such as thioglycerol (TG-CdS), mercaptopheny
ltetrazole (MPT-CdS), mercaptobenzimidazole (MBI-CdS), and mercaptoacetate
(MA-CdS) (capped CdS particles) under the stationary illumination was studi
ed by monitoring the changes in the absorption spectra to obtain knowledge
about the influence of these capping agents on photocatalytic events such a
s electron and hole transfer processes at the capped semiconductor particle
-solution interface. By the stationary illumination of the capped CdS parti
cles, the photo-aggregation of the particles was observed in water and the
photo-dissolution in organic solvents. The observed difference may be ascri
bed to the oxidative elimination of the capping agents from the CdS particl
es which occurs assisted by proton dissociation from the agents in water bu
t not in organic solvents with aprotic nature. Addition of iodide which is
known as a hole scavenger enhanced the photo-dissolution of both the capped
and ordinary non-capped CdS particles, contrary to the expected photo-aggr
egation. (C)2000 Elsevier Science S.A. All rights reserved.