Etude des propriétés structurales, optiques et photocatalytiques de nanocomposites ZnS/zéolithe Y synthétisés par radiolyse.

Abstract

The present study deals with würtzite ZnS nanoparticles embedded in zeolite Y, synthesized by - radiolysis. In a first step; zeolite Y (faugazite) is prepared by hydrothermal methode. In second, Zn2+ ions are fixed on the zeolite by ionic exchange. Finally, γ rays are performed on Zn-Y with thiol; which leads to the generation of ZnS-Y nanoparticles. The nanocomposites were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), UV–Visible absorption, and photoluminescence (PL). Compared to the bulk state, ZnS nanocrystals have blue – shifted UV visible absorption, with an excitonic peak situated at around 320 nm. They display a wide photoluminescence band with seven peaks in the range of 320 to 550 nm. The increase of the irradiation dose and RSH concentration results in a growth the ZnS nanocrystals and improves their optical performances. The optical as well as the structural characterizations confirmed the nanometric size of ZnS particles (ɸ = 5-18 nm). When tested in photodegradation of Congo red under sun light, ZnS-zeolite Y catalyst exhibited high efficiency.