Formation of Pt–Zn Alloy Nanoparticles by Electron-Beam Irradiation of Wurtzite ZnO in the TEM

As is well documented, platinum nanoparticles, promising for catalysts for fuel cells, exhibit better catalytic activities, when alloyed with Zn. Pre-existing syntheses of Pt–Zn alloy catalysts are composed of a number of complex steps. In this study, we have demonstrated that nanoparticles of Pt–Zn alloys are simply generated by electron-beam irradiation in a transmission electron microscope of a wurtzite ZnO single-crystal specimen. The initial ZnO specimen is considered to have been contaminated by Pt during specimen preparation by focused ion beam milling. The formation of the nanoparticle is explained within the framework of ionization damage (radiolysis) by electron-beam irradiation and accompanying electrostatic charging.