Photocatalytic activity of CdS and CdSe quantum dots for degradation of 3-aminopyridine

Photoactive CdS and CdSe quantum dots (QDs) were synthesized using a size-controllable AOT/water/n-heptane microemulsion method at room temperature. Size of the QDs was controlled by varying moles of water and surfactant (AOT). QDs formed were capped with thioglycolic acid (MAA) preventing their aggregation when dispersed in aqueous solution after extraction from microemulsion media. The synthesized QDs were characterized by UV–visible spectroscopy and fluorescence spectroscopy. The optical band gaps of the synthesized QDs and their size were calculated from UV–visible absorbance spectra using Tauc plots and Brus equation, respectively. The photo-spectroscopic study of QDs shows a prominent quantum confinement effect with narrow optical band gap. The photocatalytic activity of the synthesized CdS and CdSe QDs was investigated by using 3-aminopyridine as pollutant. The study suggests that it is feasible to use sunlight as a driving force in the case of cadmium-based QDs to clean up wastewater due to their tunable optical band gap depending upon the size of the QDs.