Synthesis of Cadmium Selenide Quantum Dots, Using 2,2-Bipyridine as a Capping and Phase Transfer Agent

摘要

Cadmium selenide quantum dots (CdSe QDs), were synthesized by one-pot or water-to-organic phase transfer and capped with molten 2,2’-bipyridine (bipy). The obtained CdSe QDs by the two-step procedure, reveal average sizes of 2 nm while the one-pot are mixed with secondary salt products and bipy and are undetectable by TEM. However the absorption peak of both CdSe QDs was at 425 nm and the emission band is centered at 535 nm, with a band width at half height of 77 nm, when excited with 425 nm light. The two-step CdSe QDs synthesis has the great advantage of capping the CdSe QDs with bipy, forming a solid phase, which is easily stored and dispersed in most of the organic solvents. On the other hand, the one-pot procedure requires an extra step to remove the secondary products.