A simple one-step synthesis of ZnS nanoparticles via salt-alkali-composited-mediated method and investigation on their comparative photocatalytic activity

ZnS nanoparticles have been successfully synthesized via salt-alkali-composited-mediated method (SACM) for the first time, using a mixture of LiNO3 and LiOH (LiNO3/LiOH = 60.7:39.3) as a reaction solvent, sodium sulfide and zinc nitrate as reactants at temperature of 210 °C for 24 h in the absence of organic dispersant or capping agents. X-ray diffraction, environment scanning electron microscopy (ESEM) and Transmission electron microscopy (TEM) indicated that the as-synthesized products were well crystallized and belonged to nano-scale. Their UV–vis absorption spectrum demonstrated a band gap of 3.6406 eV corresponding to the absorption edge of 340 nm. The experimental result of photocatalytic degradation on methyl orange by the nano-ZnS showed much better photocatalysis than that by the commercial ZnS powder under the irradiation of ultraviolet light and visible light, respectively.

The TEM image shows that the as-synthesized ZnS particle size was estimated to be about 40 nm and this newly synthesized ZnS nanoparticles can be as a promising photocatalytic degradation material for the organic pollutant removal.Figure optionsDownload as PowerPoint slideHighlights
► ZnS nanoparticles with cubic phase have been successfully synthesized via salt-alkali-composited-mediated method (SACM) for the first time and this method has not been found so far.
► Its band gap (Eg) is a little bigger than commercial ZnS particle mainly due to quantum size effect.
► The as-synthesized ZnS nanoparticles show much more efficient photocatalytic degradation on methyl orange than commercial ZnS powder.