Silica Coated Metal-CdS Hybrid Nanocomposites for Photocatalytic Reactions

Abstract

In summary, the present research work involved the preparation and detailed characterization of various shapes of CdS nanostructures such as nanospheres, nanorods of different aspect ratio, spongy flower like CdS nanoparticles, core (CdS)-shell (SiO2) and SiO2 coated movable CdO@CdS morphology by UV-Vis absorption and photoluminescence spectroscopy, XRD, SEM, TEM, BET surface area, LB film and TGA etc. Their relative optical absorption, band position, photoluminescence, and photocatalytic redox properties both under UV and visible light illumination, and the photostability by SiO2 coating were investigated elaborately in correlation to their size, shape, effect of metal loading, impact of laser exposure, crystal structure, crystallinity, band gap energy, surface area etc. Furthermore, CdS morphologies were also stabilized against its photodissolution by SiO2 coating which results in the formation of core-shell structures that improved the photochemical activity and stability of CdS nanoparticles during longer light exposure. Multiple-movable core (CdS)-shell (CdO) structures enclosed in lengthy SiO2 matrix were synthesized by photoetching of CdS core using monochromatic light irradiation from Ar ion laser. Different transition metals (Au, Ag, Cu, Pt, Pd and Rh) were loaded on the synthesized CdS nanostructures for finding the best and effective photocatalytic activity of metal-CdS heterocomposite