Abstract
Hexagonal CdSe and hexagonal CdS nanoparticles have been prepared using Cd(Ac)2 and less hazardous elemental Se or S as precursors, respectively, with the aid of ultrasound irradiation under an atmosphere of H2/Ar (5/95, V/V). The products consist of 7-10nm nanocrystallites which aggregated in the form of polydispersive nanoclusters with sizes in the range 30-40nm in the case of CdSe, and near monodispersive nanoclusters with a mean size of about 40nm in the case of CdS. X-ray diffraction, high-resolution TEM and SAED patterns (selected area electron diffraction patterns) show that the as-prepared particles are well crystallized. X-ray photoelectron spectroscopy (XPS) measurements further confirm the formation of CdSe and CdS. Diffuse reflection spectra indicate that both the CdSe and the CdS nanocryslallites are direct band-gap semiconductors with band-gap values of about 1.83 and 2.62eV, respectively. Control experiments demonstrate that the hydrogen is the reducing agent, and the extreme high temperature induced by the collapse of the bubble accelerates the reduction of elemental Se or S by hydrogen. An ultrasound assisted in situ reduction/combination mechanism is proposed.
Original language | English |
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Pages (from-to) | 102-110 |
Number of pages | 9 |
Journal | Journal of Solid State Chemistry |
Volume | 172 |
Issue number | 1 |
DOIs | |
State | Published - Apr 2003 |
Bibliographical note
Funding Information:Li H. L. thanks the Bar-Ilan Research Authority for a post-doctoral fellowship. Zhu Y. C. thanks the Kort 100 Scholarship Foundation for supporting his postdoctoral fellowships. Gedanken A. thanks the German Ministry of Science for the support of this work through the Deutche-Israeli DIP program. The authors are grateful to Prof. Deutsch, M., Department of Physics and Mrs. Judy, Department of Life Science, for extending the use of their facilities to us. We thank Dr. Shifra Hochberg for editorial assistance. Kind assistance from Mrs. Avivi S., Dr. Kumar V. Ganesh, Mr. Pol Vilas G., Mr. Motiei Menachem and Mr. Grisaru Haviv is gratefully acknowledged.
Funding
Li H. L. thanks the Bar-Ilan Research Authority for a post-doctoral fellowship. Zhu Y. C. thanks the Kort 100 Scholarship Foundation for supporting his postdoctoral fellowships. Gedanken A. thanks the German Ministry of Science for the support of this work through the Deutche-Israeli DIP program. The authors are grateful to Prof. Deutsch, M., Department of Physics and Mrs. Judy, Department of Life Science, for extending the use of their facilities to us. We thank Dr. Shifra Hochberg for editorial assistance. Kind assistance from Mrs. Avivi S., Dr. Kumar V. Ganesh, Mr. Pol Vilas G., Mr. Motiei Menachem and Mr. Grisaru Haviv is gratefully acknowledged.
Funders | Funder number |
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Bar-Ilan Research Authority | |
Bundesministerium für Bildung und Forschung |
Keywords
- CdS
- CdSe
- DRS
- Nanoparticles
- TEM
- Ultrasound
- XPS
- XRD