Self-Organized Platinum Nanoparticles on Freestanding Graphene

TL;DR

This study demonstrates the successful functionalization of freestanding graphene with well-distributed platinum nanoparticles, revealing unique orientation and exposure characteristics with implications for catalysis and electronics.

Contribution

It introduces a novel method for self-organizing platinum nanoparticles on freestanding graphene, with detailed microscopy and simulations elucidating their orientation and exposure.

Findings

Homogeneous distribution of single-crystal Pt NPs

Pt NPs exhibit preferred orientation

Partial exposure of Pt NPs above graphene surface

Abstract

Freestanding graphene membranes were successfully functionalized with platinum nanoparticles (Pt NPs). High-resolution transmission electron microscopy revealed a homogeneous distribution of single-crystal Pt NPs that tend to exhibit a preferred orientation. Unexpectedly, the NPs were also found to be partially exposed to the vacuum with the top Pt surface raised above the graphene substrate, as deduced from atomic-scale scanning tunneling microscopy images and detailed molecular dynamics simulations. Local strain accumulation during the growth process is thought to be the origin of the NP self-organization. These findings are expected to shape future approaches in developing Pt NP catalysts for fuel cells as well as NP-functionalized graphene based high-performance electronics.