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.