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

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.