| Affiliation: | 1.International Research Center “Smart Materials”,Southern Federal University,Rostov-on-Don,Russia;2.Research Institute of Physical and Organic Chemistry,Southern Federal University,Rostov-on-Don,Russia;3.Department of Chemistry,University of Turin,Turin,Italy |
| Abstract: | The synthesis of zinc sulfide (ZnS) quantum dots (QDs) by microwave heating in a water-ethanol medium is proposed. The effect of the synthesis temperature (80 °C, 100 °C, 120 °C, and 150 °C) on the QD characteristics is examined. Based on the analysis of X-ray diffraction profiles the conclusion is drawn that the hexagonal ZnS phase of wurtzite type with an average nanocrystal size of 2.6-3.7 nm forms in the synthesized QDs. The nanocrystallite size is found to increase with the QD synthesis heating temperature. The analysis of X-ray absorption spectra (XANES) at the zinc K-edge indicates a higher crystallinity of the QD samples prepared at higher synthesis temperatures. The combined analysis of X-ray diffraction profiles, optical diffuse reflectance spectra, and X-ray absorption spectra implies the following possible QD structure: the pure hexagonal ZnS phase of wurtzite type in the bulk of nanoparticles and the amorphous ZnO phase in the surface layer of nanoparticles. |
