Plasmon-enhanced Hydrogen evolution reaction kinetics through the strong coupling of Au-O Bond on Au-MoO2 heterostructure nanosheets

Abstract How do the synergistic effects work and which dominate the distribution of active sites, that's an interesting question in mang plasmon-enhanced catalysis. Herein, we put a deep insight into the distribution of active sites and the mechanism of charge transfer at the noble metal-metal oxide interface for accelerating the hydrogen evolution reaction (HER) kinetics. A heterostructure of Au loaded MoO2 nanosheets (Au-MoO2) is prepared by the light-reduction method. EXAFS analysis demonstrates the tight coupling at Au-MoO2 interface through the Au-O bond. An enhanced HER activity is observed with an overpotential decrease of (Δη) 176 mV and Tafel slop down to 52.5 mV/dec. KPFM measurement and FEM simulation verify the high local field enhancement at the junction. This field induces the concentrated surface charge through the Au-O bond. DFT calculation confirms the upraises filling of Op orbital in the Au-O bond, thus degrading the hydrogen adsorption energy level for HER kinetics.