Synthesis and electrocatalytic properties of AgxAuy/Fe3O4 composite microspheres and nanoparticles

Abstract

Two synthetic projects were designed to prepare AgxAuy/Fe3O4 composite microspheres and nanoparticles via one-step hydrothermal method. The as-prepared samples were characterized by using XRD, XPS, TEM and SEM techniques, respectively. The AgxAuy/Fe3O4 composite microspheres had the uniform size with 110 nm or so. The size of AgxAuy/Fe3O4 composite nanoparticles was not uniform and Ag and Au nanoparticles were dispersed in Fe3O4. The AgxAuy/Fe3O4 composite microspheres and nanoparticles were modified on glassy carbon electrodes and their electrocatalytic performances for p-nitrophenol reduction in a base medium were investigated. The results show that Fe3O4 microspheres and nanoparticles mingled with Au showed higher electrocatalytic activity than the pure Fe3O4. As Fe3O4 was loaded with Ag and Au, the electrocatalytic activity of AgxAuy/Fe3O4 composite microspheres increased first then decreased with increasing Ag content, but the activity of AgxAuy/Fe3O4 composite nanoparticles increased with increasing Ag content.