Green Synthesis, Optical, Structural, Photocatalytic, Fluorescence Quenching and Degradation Studies of ZnS Nanoparticles.

The study describes a simple hydrothermal method for the synthesis of zinc sulfide nanoparticles (ZnS NPs) using bovine serum albumin (BSA). The synthesized NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), fluorescence, UV-visible diffuse reflectance spectra (DRS) and zeta potential techniques. The morphologies and sizes were characterized by SEM and TEM. The size of ZnS NPs was observed with an effective diameter size of 20 nm. The photocatalytic activity of ZnS NPs was evaluated by the degradation of rhodamine B (RB) dye under sunlight irradiation. The degradation reaction follows the pseudo-first order kinetics. In addition, the fluorescence quenching and binding of ZnS NPs with crystal violet (CV) molecules have been studied. The binding constant (Ka) between ZnS NPs and CV is calculated using modified Stern-Volmer equation. The photocatalytic degradation and kinetics of CV dye by ZnS NPs in the presence of UV light has been investigated using spectrofluorometer.