Facets and surface relaxation of tetrahexahedral platinum nanocrystals

Platinum tetrahexahedral (THH) nanocrystals have been prepared by an electrochemical treatment of Pt nanospheres supported on glassy carbon by square-wave potential [N. Tian , Science 316, 732 (2007)]. In this paper, the shape and facets of the THH nanocrystals have been characterized by transmission electron microscopy. Most of the exposed surfaces are close to {730} facets. Detailed relaxation of the surface atoms has been observed at surface steps. It is anticipated that the high density of atomic steps and kinks is likely related to the enhanced catalytic activity of the THH nanocrystals.