METAL SULPH]DE NANOPARTICLES - AND THEIR APPLICATIONS

Abstract

Fin monosulfide, SnS is a narrow bad gap semiconductor material which is environmentally friendly and has a great range of applications in solar cells, photovoltaic cells, NIR detectors, electronic devices. Compared to the semiconductors with cubic crystal structures the layered structure of tin suiphide causes many difficulties in the synthesis of nanocrystals with a small enough size and uniform size distribution. In this report we present different shapes and sizes of SnS nanoparticles synthesized in a simple chemical precipitation method through the reaction between SnC12, 21-120 and Na2S using mercaptoacetic acid and cysteine as capping agents, respective to prevent agglomeration. The as prepared NPs were characterized by X-Ray diffractogram (XRD), scaiming electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS) transmission electron microscopy (TEM), UV-VIS-NIR spectroscopy and fluorescence spectroscopy. The XRD results show the formation of crystalline orthorhombic phase of SnS NPs. The direct and indirect band gaps were measured from DRS (diffuse reflectance spectroscopy). The direct band gap for MAA capped SnS NPs is 1.75 eV. Blue shift of 0.45 observed in this case. The direct and indirect band gap for cysteine capped SnS NPs are 1.50 eV and 1.41eV, respectively, where a blue shift of 0.2 eV obtained for direct transition and 0.4 eV for indirect transition. The as prepared SnS NPs were used for basic blue 41 and lead ion adsorption. To increase the efficiency of the adsorbent effect p1-I, initial concentration of dye, amount of adsorbent dose, contact time were examined. The adsorption of basic b1ue4 1 followed the Langrnuir isotherm and pseudo first order kinetic model. The adsorption of Pb2 ions were studied which followed Langmuir adsorption model and pseudo first order kinetic model. It 4