ZnS/CuS nanocomposites: an effective strategy to transform UV active ZnS to UV and Vis light active ZnS

Abstract

A novel amino acid stabilized composite ZnS/ CuS photocatalyst working under visible light was successfully prepared by a co-precipitation method. The ZnS/ CuS nanocomposites with different mole ratios were synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. Absorption ranges and band gap energies, which correspond to photocatalytic behavior, were investigated by UV-Vis spectroscopy. The photocatalytic activities of ZnS/CuS nanocomposites were evaluated against the degradation of an organic dye, methylene blue, under UV light and a blue emitting LED. In this study, visible light driven photocatalysis was designed based on photo-induced direct interfacial charge transfer introduced through the modification of ZnS with CuS nanoparticles. The obtained ZnS/CuS nanocomposites exhibited excellent photocatalytic activity and good reusability compared with pure ZnS nanoparticles. Results clearly showed that the ZnS/CuS nanocomposite at a 4:1 mol ratio exhibited the highest photocatalytic activity indicated by the degradation of methylene blue under UV and visible light.