White emissive alloyed core-shell CdSe1-xSx/ZnSe QDs: synthesis via a novel approach, investigating optical properties and application for photodegradation of methyl orange (MO)

Alloyed CdSe1-xSx QDs were synthesised using a simple and rapid microwave method and UV irradiation was utilised for the growth of ZnSe as shell. The synthesised QDs were characterised by means of different analyses, such as XRD (X-ray diffraction), UV-vis (UV-Visible) absorption and photoluminescence spectroscopies. Estimation of the band gap using Vegard's law for the determination of alloyed structure revealed a nonlinear relationship between the band gap energy and S concentration. ZnSe shell growth resulted in the decrease of surface trap states and appearing a near-band-edge emission with a peak at about 480 nm which made them as good white emissive QDs with CIE (International Commission on Illumination) coordinate of about (0.34, 0.38). Photocatalytic activity of the prepared QDs was investigated choosing methyl orange as pollutant target. After ZnSe shell growth, the photocatalytic activity demonstrates an enhancement compared to the bare core particles.