Plasmonic Hot-Electron-Assisted Piezocatalyst for Highly Effective Piezo-Photo Catalytic Hydrogen Evolution Via Au Nanoparticles@MoS2 Nanoflowers

Abstract

This work, Au nanoparticles@MoS2 nanoflowers (Au NPs@MoS2 NFs) heterostructure sonicated with visible light has been confirmed it can enhance piezo-photo catalytic activity for hydrogen evolution reaction. MoS2 displays prominent photocatalytic properties due to its narrow bandgap and obsesses unique piezoelectricity at its edge sites. However, the high rate of electrons and holes recombination and lack of active sites limit efficiency for hydrogen evolution. Herein introduction of Au NPs into MoS2 NFs has been synthesized by a facile hydrothermal process and forms heterojunction structure. The transmission electron microscopy (TEM) images evidence the as-synthesized Au@MoS2 heterostructure exhibits a high surface to volume with abundant nanopetals. As compared to Au NPs decorated MoS2, utilizing Au NPs burying beneath MoS2 NFs eliminates the shielding effect of MoS2 active edge sites. Based on the cathodoluminescence (CL) spectrum, Au@MoS2 achieved to reduce the recombination possibility of electrons and holes. Through gas chromatography (GC) analysis, the hydrogen evolution of 40 nm Au@MoS2 shows over 150% better than pristine MoS2. The significant improvement arises from piezoelectricity inducing hot electron of surface plasmon resonance (SPR) effect as observed by the absorption spectrum of ultraviolet-visible (UV-Vis) spectrophotometer. The COMSOL software was employed to simulate the electric field with strain on MoS2. The mechanism on SPR-enhanced piezo-photo catalytic hydrogen evolution will be investigated.