Effect of Coinage Metal (Au, Ag & Cu) Loading on CdS Nanorod Composites for Photoreduction of Nitro Organics

Abstract

This thesis demonstrates the preparation and characterization of 1 wt % coinage metal loaded CdS nanorod composites (Photodeposited and doped) in argon atmosphere under direct sunlight to study the photoreduction of nitroaromatics (p-nitrophenol, p-chloronitrobenzene and p-dinitrobenzene). The optical properties are characterized by diffused reflectance spectra, photoluminescence, X-ray diffraction and the photoactivity study is done by UV-vis spectroscopy and HPLC. It is found that the coinage metal (Au, Ag & Cu) loaded CdS nanorods showed always better photoactivity than bare CdS nanorods, due to the fact that, metal loading prevents the electron-hole recombination rate of the photogenerated charged carriers and also decreased the band gap. Among metal photodeposited and metal doped CdS-nanorods, metal doped showed better optical and photoactivity because of higher photoexcited charge separation ability, uniform dispersion of metal n+ ions, surface structural distortion, imparting extra electrons and uniformly mixing of metal with crystal, which resulted in the ease of charge transfer to reactant species.