Nowadays QDs have been used in different fields such as biological labeling, optoelectronics, photovoltaics, sensing, and catalysis. There are a variety of approaches to the synthesis of chalcogenide QDs due to the requirements for the various shape, size and, as consequence, their optical properties. Unlike the synthesis of previously published sulfur precursors, we present new synthetic possibilities of eco-friendly disubstituted thioureas for the preparation of Cd0.2Zn0.8S QDs. On the basis of natural sources such as L-valine, L-leucine and (+)-3-carene, the corresponding β-amino alcohols were obtained and further converted to N,N’-disubstituted thioureas by reaction with isothiocyanates. Synthesis of Cd0.2Zn0.8S QDs was carried out in an organic dispersion medium with a non-coordinating solvent 1-octadecene (ODE). A solution of N,N’-disubstituted thiourea in oleylamine (OAm) was injected to the in situ synthesized cadmium and zinc linoleates at 260 °C in Ar atmosphere. The nucleation and growth of nanocrystals were monitored by taking aliquots from the reaction mixture. In order to obtain comparable results during the synthesis of Cd0.2Zn0.8S QDs, the same reaction conditions for each of the N,N’-disubstituted thioureas were maintained. The structure and composition of the prepared nanopowders were determined by X-ray and EDS spectroscopy. TEM measurements gave evidence QDs´ shape and size variation due to the influence of various sulfur precursor chiral fragments nature. The availability of raw materials and simplicity of synthesis can potentially allow to transfer the laboratory synthesis of highly photoluminescent Cd0.2Zn0.8S QDs (quantum yield up to 60%) into an industrial scale. Acknowledgments Authors appreciate financial support from project “High-sensitive and low-density materials based on polymeric nanocomposites” – NANOMAT (№ Z.02.1.01/0.0/0.0/17_048/0007376), support from the grants LM2015082 and ED4.100/11.0251 from the Ministry of Education, Youth and Sports of the Czech Republic and European Regional Development Fund-Project "Modernization and upgrade of the CEMNAT" (No. CZ.02.1.01/0.0/0.0/16_013/0001829). Serghei Curlat acknowledges scholarship 51810769 from International Vishegrad Fund.
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