Reversible attachment of platinum alloy nanoparticles to non-functionalized carbon nanotubes

TL;DR

This study demonstrates the reversible attachment of alloyed platinum nanoparticles to non-functionalized carbon nanotubes, with control over nanoparticle properties and interactions, relevant for catalysis and energy storage applications.

Contribution

It introduces a method for reversible nanoparticle attachment to carbon nanotubes without functionalization, using ligand-controlled interactions and first-principles calculations.

Findings

Nanoparticles attach during synthesis depending on ligand and work function.

Attachment does not modify the carbon lattice's hybridization.

Reversible interactions are confirmed by spectroscopic and computational analysis.

Abstract

The formation of monodisperse, tunable sized, alloyed nanoparticles of Ni, Co, or Fe with Pt and pure Pt nanoparticles attached to carbon nanotubes has been investigated. Following homogeneous nucleation, nanoparticles attach directly to non-functionalized singlewall and multiwall carbon nanotubes during nanoparticle synthesis as a function of ligand nature and the nanoparticle work function. These ligands do not only provide a way to tune the chemical composition, size and shape of the nanoparticles but also control a strong reversible interaction with carbon nanotubes and permit controlling the nanoparticle coverage. Raman spectroscopy reveals that the sp2 hybridization of the carbon lattice is not modified by the attachment. In order to better understand the interaction between the directly attached nanoparticles and the non-functionalized carbon nanotubes we employed first-principles calculations on model systems of small Pt clusters and both zig-zag and armchair singlewall carbon nanotubes. The detailed comprehension of such systems is of major importance since they find applications in catalysis and energy storage.