Boron Nitride Nanomesh: A template for Nano-ice

TL;DR

This study uses advanced microscopy techniques to explore water molecule arrangements on a boron nitride nanomesh, revealing nano-ice formation and distinct phases within the nanostructure.

Contribution

It provides detailed structural insights into water self-assembly and nano-ice formation on h-BN/Rh(111) nanomesh, a novel template for nanoscale ice.

Findings

Ordered nano-ice crystals form in 2 nm holes with a bilayer honeycomb structure.

A low density gas phase exists on 1 nm wires, showing contrast modulations.

Tunneling barrier measurements reveal proton positions in nano-ice clusters.

Abstract

Using variable temperature scanning tunneling microscopy and dI/dz barrier height spectroscopy, the structure of water on h-BN/Rh(111) nanomesh has been investigated. Below its desorption temperature, two distinct phases of water self-assemble within the 3.2 nm unit cell of the nanomesh. In the 2 nm holes, an ordered phase of nano-ice crystals with about 40 molecules is found. The ice crystals arrange in a bilayer honeycomb lattice, where the hydrogen atoms of the lower layer point to the substrate. The phase on the 1 nm wires, is a low density gas phase, which is characterized by contrast modulations and streaky noise in the STM images. Tunneling barrier measurements infer the proton positions in the nano-ice clusters.