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

TL;DR

This study demonstrates that decorating MoS2 nanosheets with plasmonic gold nanoparticles significantly enhances their photocatalytic efficiency in degrading organic dyes under light, offering potential environmental remediation applications.

Contribution

The paper introduces a novel Au-MoS2 nanostructure with improved photocatalytic activity due to gold nanoparticle decoration, advancing the field of nanomaterial-based environmental cleanup.

Findings

Au NPs increase dye degradation efficiency from ~30-47% to over 70-96%.

Au-MoS2 shows superior performance compared to pristine MoS2.

Enhanced photocatalytic activity attributed to charge trapping by Au NPs.

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.