Origin and shape evolution of core-shell nanoparticles in Au-Pd: from few atoms to high miller index facets

Authors

Nabraj Bhattarai, University Of Texas At San Antonio
Gilberto Casillas, University of Texas at San AntonioFollow
Subarna Khanal, University Of Texas At San Antonio
Jesus Velazquez-Salazar, University Of Texas At San Antonio
Arturo Ponce, University Of Texas At San Antonio
Miguel Jose-Yacaman, University of Texas at San Antonio

RIS ID

81377

Publication Details

Bhattarai, N., Casillas, G., Khanal, S., Velazquez-Salazar, J., Ponce, A. & Jose-Yacaman, M. (2013). Origin and shape evolution of core-shell nanoparticles in Au-Pd: from few atoms to high miller index facets. Journal of Nanoparticle Research, 15 (6), 1-13.

Abstract

Au-Pd core-shell nanocubes and triangular nanoparticles were systematically synthesized from a few Pd layers up to fully grown morphologies by a modified seed-mediated growth method. The shape evolution of Au-Pd core-shell nanoparticles from single crystal and singly twinned seed to final concave nanocube and triangular plates are presented at atomic level by Cs-corrected scanning transmission electron microscopy (STEM). The growth mechanism of both morphologies was studied throughout different sizes. It was found that the concave nanocubes grew from octahedral Au seeds due to fast growth along h111i directions; while the triangular nanoparticles grew from singly twinned Au seeds, growing twice as fast in h110i directions along the twin boundary; compared to the h111i direction perpendicular to the twin boundary. Both the concave nanocubes and triangular nanoparticles presented high index facet (HIF) surfaces that will increase the catalytic activity of different reactions.