PREPARATION AND CHARACTERIZATION OF CDS NANOCRYSTALLITES IN NAFION

Perfluoroethylene sulfonic acid polymer (NAFION) films are subjected t o ion exchange in the medium of aqueous solutions of cadmium acetate, followed by ammonia passivation. The films are then treated with hydro gen sulfide gas for prescribed times. X-ray powder diffraction data of these samples have been analyzed for estimating the sizes of the nano crystallites. The optical absorption spectra of the samples show an ab sorption edge beginning at 525 nm for the largest size clusters. A bro ad absorption band appears with a maximum around 410 nm-440 nm in the smaller size clusters.