Growth mechanism of core–shell PtNi–Ni nanoparticles using in situ transmission electron microscopy†
Controlling the growth, morphology and structure of nanocrystals is fundamental to achieving facet dependent physical and chemical properties. Core–shell PtNi–Ni nanoparticles’ evolution was investigated using in situ liquid cell transmission electron microscopy (TEM). A two-stage growth of core–shell PtNi–Ni nanoparticles was observed. The platinum (Pt)-based binary alloy was formed initially by a thermodynamically driven process, then grown by a monomer attachment process, and then the core formed and the process was stopped by depletion of the Pt precursor, and finally the nickel (Ni) shell formed. This growth process gives a way to grow a metallic shell for novel catalysts.