Plasmon-assisted MoS ₂ @Au nanocomposite for enhanced photocatalysis of organic dye degradation

In this study, MoS 2 @Au nanocomposite was synthesized using a hydrothermal method to explore its enhanced photocatalytic efficiency under visible-light. MoS 2 samples were prepared at varying reaction times (3, 6, 9, 12, 15 and 18[Formula: see text]h) to investigate the influence of crystallization and morphology on their optical properties. The sample, prepared at 18[Formula: see text]h reaction time, exhibited the highest crystallinity and was subsequently utilized for the formation of MoS 2 @Au by the in situ reduction of HAuCl4 to deposit [Formula: see text]40[Formula: see text]nm Au nanoparticles on the MoS 2 surface. Structural, optical and morphological characterizations were carried out using XRD, UV–Vis spectroscopy and FE-SEM analyses. The XRD results confirmed the hexagonal phase of MoS 2 nanoflowers with additional peaks corresponding to Au. The MoS 2 @Au composite showed a red shift in absorption and a decreased band gap, indicating efficient plasmonic coupling. Photocatalytic degradation studies using methylene blue under visible-light demonstrated that MoS 2 @Au exhibited superior performance compared to pristine MoS 2 , attributed to enhanced charge separation and localized surface plasmon resonance of Au. These findings highlight MoS 2 @Au as a promising nanocomposite for environmental remediation and photocatalytic applications.