Growth mechanism of core-shell PtNi-Ni nanoparticles using in situ transmission electron microscopy

摘要

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.