Researchers at the National University of Science and the Agency for Science, Technology and Research used Hummingbird Scientific’s Liquid Heating TEM specimen holder to study intermediate structures during selective chemical and electrochemical etching of nanoparticles. They observed selective chemical and electrochemical Ni etching of Pt–Ni NPs in-situ in the TEM. They showed that intermediate structures evolve differently in different cases. Whereas chemical etching of Ni forms localized pits on the surface of the nanoparticle, electrochemical etching shows uniform dissolution of Ni.

‍

Their study reveals how oxidative etching removes the non-noble metal and leaves noble-metal-rich nanoparticles. With this the researchers show that the native oxide layer affects the etching behavior, which is an important insight for the design of nanoparticles.

‍

These nanoparticles are important for considerations as electrocatalysists. Understanding their etching behavior will help in understanding how to optimally design these particles for that use.

‍

Reference:

Intermediate Structures of Pt–Ni Nanoparticles during Selective Chemical and Electrochemical Etching, Shu Fen Tan, See Wee Chee, Zhaslan Baraissov, Hongmei Jin, Teck Leong Tan and Utkur Mirsaidov, Phys. Chem. Lett.201910206090-6096