Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5364795 | Applied Surface Science | 2010 | 4 Pages |
Abstract
Starch capped cadmium sulfide (CdS) nanoparticles were synthesized by aqueous solution precipitation. Starch added during the synthesis of nanoparticles resulted in cadmium-rich nanoparticles forming a stable complex with starch. The size of the CdS quantum dots was measured using high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The average diameter (d) of nanoparticles spanned the range 4.8 ± 0.4 to 5.7 ± 0.2 nm when the pH of the solution was varied within the range 10-14. The main Raman phonon of CdS, the longitudinal optical mode located around 300 cmâ1, softens as diameter decreases, in accordance with theoretical predictions. In addition, the largest Raman response of starch, near 478 cmâ1, related with the important skeletal vibration modes of the starch pyranose ring, dominates the spectra of the CdS capped nanoparticles and also softens as the size decreases. This fact indicates a strain variation on CdS as a function of d which increases as the pH increases.
Keywords
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
P. RodrÃguez-Fragoso, G. González de la Cruz, S.A. Tomas, O. Zelaya-Angel,