Biography
Biography: Metwally Madkour
Abstract
Semiconductor quantum dots are promising candidates for the future optoelectronic applications and energy applications. Doped semiconductors with noble metals such as Au and Ag are called a plasmonic photocatalyst. In this study, eco-friendly well dispersed undoped ZnS quantum dots, QDs, and noble metal doped ZnS QDs (loading amount 4 wt.%) were successfully synthesized on large scale via a green aqueous route at room temperature. The synthesized nanoparticles were characterized via different techniques such as: XRD, XPS, TEM and SEM. The synthesized nanoparticles with its small particle size of 4.5 nm revealed quantum size effect in terms of blue shift in the absorption behaviour with optical band gap, Eg, of 5.06 eV. The photocatalytic activities of bare and doped ZnS QDs were assessed toward the photocatalytic degradation of methylene blue dye. The results revealed a superior photo-efficiency upon doping with noble metal nanoparticles. This superior photocatalytic behaviour of the noble metal doped ZnS QDs photocatalysts could be mainly attributed to Schottky barrier of noble metals which prevents the recombination of the charge carriers and prolongs the lifetime of the photogenerated electrons.