Fig. 1: In situ LPTEM observation of the Pd atom and Pd nanoparticle deposition on chiral AuAg nanowire in atomic resolution.
A HRSTEM image of the chiral AuAg nanowire which showing typical Boerdijk-Coxeter-Bernal Structure as reported41. The inserted image shows the corresponding FFT obtained along the axis of the nanowire in the right to identify Boerdijk-Coxeter-Bernal lattice. B Snapshot image depicts the dynamic process of Pd deposition on a chiral AuAg nanowire: atomic-scale observations reveal an increase in nanowire diameter and the emergence of distinct lattice patterns in Pd〈111〉 direction with time (Red arrow shows the outline of the chiral seed nanowire, and the position of Pd deposition). The electron dose rate was 8.4 e·Å−2·s−1. C Snapshot image depicts the dynamic process of Pd nanoparticle deposition directly on a AuAg nanowire in colloids: the green circle highlights some attached Pd nanoparticles on AuAg seed nanowire followed by covalence whose positions are labelled by red arrows. The electron dose rate was 7.5 e·Å−2·s−1. D The STEM images show the formation of a double-helical nanowire after Pd deposition on the chiral seed nanowire. The surface of the resulting nanowire reveals the outlines of Pd nanoparticles, as indicated by the red arrows. E Schematics show the noble metal deposition hypothesis by using a chiral AuAg alloy nanowire as seed. The heterogeneous nucleation, homogeneous nucleation, nanoparticle attachment, Ostwald ripening, and nanoparticle coalescence lead to a competitive growth mode giving double helical core-shell nanowires.
