Journal of Physical Chemistry, Vol.99, No.24, 9893-9897, 1995
Electron-Spin-Resonance Study of Radicals Produced on Irradiated CdS Powder
ESR measurements were carried out for wurtzite (W) and zinc-blende (ZB) CdS powders at 77 K under light irradiation. ESR signals at g = 2.004-2.035 were detected for each crystal structure. The signals decreased on contact with 2-propanol and were assigned to trapped holes. The W CdS is active for oxidation reactions rather than the ZB CdS since the formation of 2-hydroxy-2-propyl radical was clearly observed. Reduction of methylviologen was observed for some CdS powders. The difference in the photoinduced ESR spectra was discussed with the morphology of the particles obtained from transmission electron microscopy.
Keywords:PARAMAGNETIC-RESONANCE;METAL SULFIDES;TIO2 COLLOIDS;TRAPPED HOLES;PHOTOLUMINESCENCE;SUSPENSIONS;ESR