Exfoliated MoS2 supported Au–Pd bimetallic nanoparticles with core–shell structures and superior peroxidase-like activities

Abstract

Au–Pd bimetallic nanoparticles (NPs) with core–shell structures have been successfully anchored on chemical exfoliated MoS₂ (Au–Pd/MoS₂) through a facile co-reduction method at room temperature. The Au–Pd/MoS₂ hybrids were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The pristine MoS₂ nanosheets exhibit some peroxidase-like activity for the oxidation of 3,3,5,5-tetramethylbenzidine (TMB), and their catalytic activity is significantly enhanced by the deposition of Au–Pd NPs. A systematic study revealed that Au–Pd NPs with a mass ratio of 1 : 2 on MoS₂ (Au_1.0Pd_2.0/MoS₂) showed the highest catalytic activity compared with other counterparts. This excellent performance of the Au_1.0Pd_2.0/MoS₂ hybrids should be ascribed to not only the intrinsic catalytic activity of MoS₂, but also the complicated metal–metal and metal–support interactions.