(Invited) Controlled Synthesis of Hollow Bimetallic Nanoparticles As Photo and Electrochemical Catalysts

Abstract

Noble metal based bimetallic nanoparticles are promising photo and electrochemical catalysts. In particular, hollow bimetallic nanoparticles with high surface areas show promising performance in many photo and electrochemical driven reaction. In this work, we synthesized hollow Au, Pt and Pd based bimetallic nanoparticles using methods including galvanic replacement, thermal treatment, and acid treatment of solid core@shell or alloy nanoparticles. The structural change of the nanoparticles from solid to hollow was monitored with transmission electron microscopy along with single particle scattering spectroscopy. In Au-Cu nanorod system, we found that through careful control of the reaction kinetics of galvanic replacement and diffusion of atoms in the nanorod, internal structures of the hollow nanorods can be exquisitely controlled. The Pt and Pd based hollow bimetallic nanoparticles showed good activity and stability as catalysts for oxygen reduction reaction.