Morphology Controlled CdS Nanostructures: A Proficient Visible-Light-Driven Photocatalyst

Abstract

Visible light driven catalytically active CdS morphologies viz. nanoparticles, nanorods, nanospheres and nanoflowers were fabricated via facile and versatile solvothermal method by adjusting the experimental conditions. The fabricated samples were critically analyzed using Powder X-ray Diffraction, High Resolution Transmission Electron Microscopy, Brunauer-Emmett-Teller and UV-vis Diffused Reflectance Spectrum. Elemental composition of CdS samples was confirmed by using Energy Dispersive X-ray Spectroscopy. Crystallite size for CdS nanoparticles was found to be ∼ 4 nm while in case of other morphologies, it was found to be in range of 27-33 nm. Optical studies revealed the information about the band gap of visible light responsive photocatalysts and covered the solar spectrum from 525 nm to 650 nm. Photocatalytic activities of all the CdS morphologies were compared using methylene blue, methyl orange, safranin O, rhodamine B and remazol brilliant yellow as probe molecule. The different CdS morphologies were found to exhibit dissimilar catalytic efficacy, which was due to the fact that there was large difference in the surface area of the samples. The experimental results were found to be in accordance with the order: CdS nanoparticles > CdS nanorods > CdS nanospheres ∼ CdS nanoflowers. Therefore, CdS morphology with better catalytic activity can be deduced as an ideal catalyst for the treatment of dye waste water.