Growth of Pt Nanowires\nby Atomic Layer Deposition\non Highly Ordered Pyrolytic Graphite

Abstract

The formation of Pt nanowires (NWs) by atomic layer deposition\non highly ordered pyrolytic graphite (HOPG) is investigated. Pt is\ndeposited only at the step edges of HOPG and not on the basal planes,\nleading to the formation of laterally aligned Pt NWs. A growth model\ninvolving a morphological transition from 0-D to 1-D structures via\ncoalescence is presented. The width of the NWs grows at a rate greater\nthan twice the vertical growth rate. This asymmetry is ascribed to\nthe wetting properties of Pt on HOPG as influenced by the formation\nof graphene oxide. A difference in Pt growth kinetics based on crystallographic\norientation may also contribute.