Three-dimensional architecture of Ag/CeO2 nanorod composites prepared by dealloying and their electrocatalytic performance

Abstract

A novel three-dimensional (3D) architecture of Ag/CeO2 nanorods with high electrocatalytic activity was prepared by dealloying melt-spun Al-Ag-Ce alloys in NaOH aqueous solutions for NaBH4 electro-oxidation. The nanorod composite was composed of CeO2 nanorods and large-size Ag nanoparticles. After undergoing calcination at 573 K in air, many highly dispersed small Ag nanoparticles were generated and deposited on the surface of the CeO2 nanorod framework. Well-defined Ag/CeO2 interfaces were created via the anchoring of small Ag nanoparticles on the CeO2 nanorods, and the nanorods were connected by larger conductive Ag nanoparticles. Electrochemical measurements showed that the mass specific current of the Ag/CeO2 composites was 2.5 times higher than that of pure Ag for BH4- oxidation. The Ag/CeO2 composites exhibited enhanced catalytic activity owing to the 3D nanorod architecture, strong interfacial interactions between small Ag nanoparticles and CeO2 nanorods, and high concentrations of surface oxygen species.