Highly efficient photo-degradation of methyl blue and band gap shift of SnS nanoparticles under different sonication frequencies

Stannous sulfide (SnS) nanoparticles (NPs) were synthesized via a sonochemical route with 20 and 50 kHz sonication frequencies. Structure study revealed an orthorhombic phase of SnS. The SnS NPs that were synthesized by 20 kHz sonication had smaller diameter in comparison to the NPs that were synthesized by 50 kHz sonication. An optical investigation confirmed that the SnS particles had strong emission bands located at the UV and visible regions and suggested that they have the potential to be used as optical devices. This inference was further strengthened by the absorption coefficient values. In addition, their photocatalytic properties were tested by degrading methyl blue in distilled water under visible light. The results showed that SnS nanoparticles synthesized under the lower sonication frequency had better photocatalytic activity. Given these results, the sonication frequency appears to be an important synthesis parameter in the formation of SnS nanoparticles and their optical and photocatalytic properties.