Structural characterization of Au nano bipyramids: reshaping under thermal annealing, the capping agent effect and surface decoration with Pt

Anisotropic gold nanoparticles offer potential applications due to their functionalities and shape-dependent properties. Reshaping noble metal nanoparticles is an interesting field with optical, surface-enhanced Raman spectroscopy, catalytic applications and potential application as a photothermic therapy. This work comprises a structural study on gold nano bipyramids (Au NBPs) and nanodumbbells, and the evolution of Au NBPs capped with cetyltrimethylammonium bromide and dodecanethiol through an in situ and ex situ heating process in high vacuum. Also, we study the reshaping of Au NBPs by the addition of Pt to study the surface modification and the strain generated on a single particle by geometric phase analysis.