Naturally self-assembled nickel nanolattice

TL;DR

This study reveals that monodispersed nickel nanoparticles with specific sizes can naturally form hexagonal close-packed nanolattices driven by surfactant chemistry, offering new insights into nanolattice fabrication and applications.

Contribution

It is the first report demonstrating the critical role of surfactant type, especially trioctylphosphine, in naturally forming nanolattices of nickel nanoparticles without external forces.

Findings

Nickel nanoparticles (~4-10nm) form hcp nanolattices with trioctylphosphine.

The c/a ratios match those of atomic lattices.

Nanolattice formation explained by surfactant-induced forces.

Abstract

This is the first report on the critical nature of nanolattice formability of different particle size (~4-10nm) of monodispersed nickel nanoparticles. They exhibit strikingly hexagonal close-packed (hcp) nanolattices without extra forces, whenever trioctylphosphine is (one of) the surfactant(s). This clearly establishes the unique role of nanolattice formability of trioctylphosphine. The c/a ratios are interestingly identical to those of atomic lattices. An attempt has also been made to explain them based on the balanced attractive and repulsive forces of the surfactant-generated cation-anion pairs on the surface of the nanoparticles. The present findings therefore will provide a far-reaching vista to fabrication of varieties of natural nanolattices and their understanding on applications in a new paradigm.