Electrochemical synthesis of TGA-capped CdTe and CdSe quantum dots

Abstract

The electrochemical preparation of Te²⁻ and Se²⁻ ions was carried out in NaOH aqueous solution, with high yield and good stability, and applied in the preparation of negatively charged CdTe and CdSe quantum dots (QDs). A CdCl₂ aqueous solution containing thioglycolic acid (TGA) stabilizer was mixed with the electrochemically generated Te²⁻ or Se²⁻ ions in a quite reproducible and clean one pot process, without the use of chemical reducing agents. The CdTe and CdSe QDs had good stability and high luminescence with an average size of d = 3.9 nm and 2.6 nm, respectively, the quantum yields and lifetimes were also determined. Hg²⁺ was efficiently quantified in the presence of the synthesized TGA-capped CdTe and CdSe, making possible the application of these QDs as chemical sensors.