Plasmonic Au-MoS 2 Nanohybrids Using Pulsed Laser-Induced Photolysis Synthesis for Enhanced Visible-Light Photocatalytic Dye Degradation

The Au-MoS nanocomposites (NCPs) exhibit excellent visible-light photocatalytic activity and potential applications in the photocatalytic degradation of organic dyes. In this study, an Au-MoS heterojunction structure with Au nanoparticles (NPs) deposited on MoS nanosheets was synthesized via the pulsed laser-induced photolysis method. The influence of Au content on the photocatalytic performance was systematically investigated, and the working mechanism under visible light excitation was elucidated. The optimal Au-MoS NCPs exhibited efficient degradation of methylene blue (MB) dye, mainly attributed to the plasmon resonance effect of Au NPs which facilitated the visible light harvesting and hot electron injection. The Au/MoS interface promoted the separation and transfer of photogenerated charge carriers. The electrostatic adsorption between positively charged MB molecules and the negatively charged MoS surface favored the affinity toward active sites. Furthermore, the photogenerated electrons and holes participated in generating reactive oxygen species such as superoxide and hydroxyl radicals, which initiated the oxidative degradation of MB. The PLIP-introduced Au NPs not only endowed the material with excellent visible light responsivity but also possibly modulated the electronic structure and photocatalytic active sites of MoS through an intrinsic effect, providing new insights for further enhancing the photocatalytic performance of Au-MoS NCPs.