Enhanced photocatalytic activity of plasmonic Au nanoparticles incorporated MoS$_2$ nanosheets for degradation of organic dyes

Abstract: In the present paper, we investigate the effect of plasmonic Au nanoparticles (NPs) decoration on the photocatalytic efficiency of MoS$_2$ nanosheets. The Au NPs are grown on the surface of chemically exfoliated MoS$_2$ nanosheets by chemical reduction method. Au-MoS$_2$ nanostructures (NSs) are characterized by X-ray diffractometer, Raman spectrometer, absorption spectrophotometer, and transmission electron microscopy. Exfoliated MoS$_2$ and Au-MoS$_2$ NSs are used to study the photocatalytic degradation of organic dyes methyl red (MR) and methylene blue (MB). Under UV-Visible light irradiation, pristine MoS$_2$ shows photo degradation efficiencies between 30% to 46.9% for MR and 23.3% to 44% for MB, with varying exposure times from 30 to 120 min, respectively. However, Au-MoS$_2$ NSs with maximum Au NPs concentration show enhanced degradation efficiency from 70.2 to 96.7% for MR, and from 65.2 to 94.3% for MB. The manifold enhancement of degradation efficiency for both the dyes with Au-MoS$_2$ NSs may be attributed to the presence of Au NPs acting as charge trapping sites in the NSs. We believe this study would have potential application in battling the ill-effects of environmental degradation, which poses a major threat to humans as well as biodiversity.