Investigation of the effect of annealing on the photocatalytic activity of zinc sulfide nanostructures synthesized by Co-precipitation method

Zinc sulfide nanostructures were synthesized by a green, cost-effective, and simple co-precipitation method using the amino acid L-cysteine as a surfactant. After synthesizing and annealing the nanostructures, the obtained samples were characterized by different techniques such as X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray energy diffraction (EDX) patterns and ultraviolet-visible(UV) spectroscopy. The results of XRD and FTIR showed that zinc sulfide nanostructures have a hexagonal phase. The results of the UV-vis showed that increasing the annealing temperature led to a decrease, the band-gap energy and increase the size of the nanostructures. The prepared nanostructures were used to investigate the photocatalytic activity. The results showed that with increasing annealing temperature, the photocatalytic efficiency of nanostructures was decreased.