Tracking the atomic pathways of Pt3Ni-Ni(OH)2 core-shell structures at the gas-liquid interface by in-situ liquid cell TEM

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2020,（4）
• 页码范围: 513-518
• 页数: 6页
• 语种: 英文

摘要

Using the in-situ liquid cell transmission electron microscopy,the three-stage growth of Pt3Ni-Ni(OH)2 core-shell structures at the gas-liquid interfaces was clearly observed,which consists of (1) a thermodynamically driven Pt3Ni alloy core by the monomer attachment,(2) a nickel (Ni) shell formation due to the depletion of the Pt salt precursor,and (3) the oxidation and of the Ni shell into Ni(OH)2 flakes.We also further observed the nucleation and growth of the Ni(OH)2 flakes on an existing layer either at the middle part or at the step edge.More interestingly,the dynamic transformation among a Pt3Ni alloy,Ni clusters and Ni(OH)2 flakes was also imaged even at a high electron dose rate.