A new simple synthesis of CdS nano-particles by composite-molten-salt method and their high photocatalytic degradation activity

Nano-CdS crystal has been succesfully synthesized by composite molten salt (CMS) method for the first time, using composite molten salt as a reaction solvent, sodium sulfide and cadmium nitrate hexahydrate as reactants at temperature of 200 °C for 24 h in the absence of organic dispersant or capping agents. X-ray diffraction and field emission scanning electron microscopy (FESEM) images indicated that the as-synthesized product were well crystallized and belonged to nano-scale. Their UV–vis absorption spectrum demonstrated a band gap of 2.49 eV corresponding to the absorption edge of 499 nm. The experimental result of photocatalytic degradation on methyl orange by the nano-CdS showed much better photocatalysis than that by the commercial CdS powder under the irradiation of ultraviolet light source.

Result of this study shows that as-synthesized nano-ZnS material can effectively degrade the organic pollutant under the illumination of simple and low-power ultraviolet light.Figure optionsDownload as PowerPoint slideHighlights
► CdS nano-spherical-particles and nano-wires have been obtained by CMS method for the first time.
► Its band gap (Eg) is a little bigger than bulk CdS material mainly due to quantum size effect.
► The as-synthesized nano-CdS show much more efficient photocatalytic degradation on methyl orange than commercial CdS powder.