In-situ high-speed AFM of shape-controlled Pt nanoparticles in electrochemical environments: Structural effects on the dissolution mechanism

Abstract

Real time dissolution process of shape-controlled Pt nanoparticles (cubic, cuboctahedral, tetrahedral) has been studied using high-speed atomic force microscopy (AFM) during potential cycles in electrochemical environments. The nanoparticles are dissolved above 1.5V(RHE) when the lower limit of the potential cycle is fixed at 0.05V(RHE). Edges of cubic nanoparticles are dissolved at first, whereas the tops of cuboctahedral and tetrahedral nanoparticles are dissolved forming pseudo-flat structure at the upper terraces. The order of the durability is cuboctahedral<cubic<tetrahedral. When the upper limit of the potential cycle is fixed at 1.6V(RHE), the order of the durability depends on the lower limit of the potential cycle: cubic~cuboctahedral<tetrahedral between 0.05 and 0.2V(RHE), cubic<tetrahedral≪cuboctahedral between 0.3 and 0.6V(RHE).