Synthesis, characterization and photocatalytic degradation efficiency of CdS quantum dots embedded in sodium borosilicate glasses

Abstract

Borosilicate glass system (SiO2-B2O3-Na2O-ZnO) with the addition of 3 wt% CdS was prepared by conventional melt quenching method. Amorphous nature of glass sample was confirmed by XRD measurement. Glass transition temperature and crystallization temperature was determined from DTA curve. CdS quantum dots (QDs) were grown in this glass matrix by optimized heat treatment schedule which was confirmed by XRD measurement. The growth of CdS QDs was also confirmed by optical absorption spectra and photoluminescence (PL) measurement. Energy band gap was calculated from the absorption spectra and found to decrease with increase in size of QDs. The size of QDs measured by optical absorption and it was also confirmed by HR-TEM results. The increase in size of QDs is also noticed from emission spectra which show red shift in PL intensity. The glass embedded with CdS QDs were tested for photocatalysis study and it shows 70.6% and 68.0% photodegradation efficiency for 5 ppm and 10 ppm respectively.