Síntese de nanocristais de semicondutores em líquidos iónicos
authors Fábio Martins Silva
supervisors Tito Trindade; João Manuel Costa Araújo Pereira Coutinho
thesis type Mestrado Integrado
abstract The main objective of this work was the synthesis of copper sulfide nanocrystals in ionic liquids, and the study of its effect on the type of nanocrystals obtained. The nanocrystals were synthesized from the decomposition of single-molecular precursors in ionic liquid. Three different precursors were used: copper (II) diethyl, dibutyl and dihexildithiocarbamate, being the first prepared by direct precipitation and the other complexes by insertion of CS2 in the corresponding secondary amine, dibutylamine and dihexilamine. After the synthesis, the characterization of the precursors was assessed, in order to confirm the achievement of the desired complex and its purity. The first ionic liquid studied for the decomposition of the precursors was THTDP N(CN)2. No visible differences were observed in the product obtained for the diverse types of precursors used. In order to study the effect of the solvent in the product obtained, the decomposition of a precursor (Cu(S2CN(n-But)2)2) was made in two different ionic liquids, the THTDP NTf2 and THTDP CH3SO3, as well as in a conventional organic solvent, namely oleylamine. The different solvents used promote differences in the crystalline phase of the nanocrystals obtained showing the possibility of controlling the crystalline phase by varying the solvent used. The employment of ionic liquids in the synthesis of nanocrystals may lead to a better control of the phase of copper sulfide nanocrystals, as well as to develop a more
year published 2013
link http://hdl.handle.net/10773/12285