Optical Properties of Semiconductor nanoparticles grown in Zeolite Matrix

We report the optical and structure properties of NiS and CoS nanoparticles in ZSM-5 zeolite. The samples were obtained by sulfidation of the Ni2+ and Co2+ ion-exchange ZSM-5 zeolites in a Na2S solution at room temperature. The optical properties of the samples were studied by UV-Vis spectroscopy. Their crystalline structure and morphology were studied by XRD and scanning electron microscopy. BET and IR spectra results reveal that nanoparticles could grow on the surface area of ZSM-5 zeolites. Absorption peaks at higher energy than the fundamental absorption edge of bulk NiS and CoS indicate quantum confinement effect in nanoparticles as a consequence of their small size. The absorption spectra show that the optical band gap varies in the range 3.91-4.72 eV.