CdSe quantum dots stabilized by carboxylic-functionalized PVA: Synthesis and UV–vis spectroscopy characterization

Abstract

Quantum dots (QDs) have drawn the attention of the research community in the last decade due to their potential use in the fast developing area of nanotechnology. In this study, it is reported the synthesis and characterization CdSe nanoparticles using acid-functionalized poly(vinyl alcohol) (PVA–COOH) polymer as capping ligands via aqueous route at room temperature by methods of colloidal chemistry. Different molar concentrations of PVA–COOH were investigated aiming at producing stable nanoparticles using cadmium perchlorate and synthesized sodium selenosulfate. UV–vis spectroscopy was used to evaluate the kinetics and the relative stability of CdSe nanocrystals considering their size as-prepared and subsequent growth. The QDs sizes were estimated by the “absorbance onset” from UV–vis spectroscopy spectra, considering theoretical and empirical methods. The results have indicated that precursor solution of PVA–COOH at concentration of 1.0 mol L −1 was effective on stabilizing colloidal CdSe QDs in aqueous suspension. Moreover, ultra-small CdSe nanocrystals were produced with calculated average particles size under 2.0 nm, indicating they were in the so-called “quantum-size confinement range”. Hence, it was developed a relatively simple colloidal route using a single-step method to produce CdSe QDs water soluble and commercially available polymers that offers a window of opportunities to explore these novel nanohybrid materials.