# Chemical exfoliation of layered Al5C3N for the synthesis of AlN nanosheets

## TL;DR

Scientists developed a new method to create 2D aluminum nitride nanosheets using a layered precursor and chemical etching, enabling potential uses in sensors and microelectronics.

## Contribution

A novel synthesis route for 2D AlN nanosheets using Al5C3N precursors and hydrofluoric acid etching is introduced.

## Key findings

- Layered Al5C3N can be chemically exfoliated into AlN nanosheets using hydrofluoric acid.
- The method overcomes challenges posed by the hexagonal wurtzite structure of bulk AlN.
- This opens opportunities for exploring unique properties of 2D AlN in electronic applications.

## Abstract

Two-dimensional (2D) aluminum nitride (AlN) represents a promising material with unique properties predicted by density functional theory (DFT), characterized by a honeycomb lattice where Al and N atoms exhibit threefold in-plane coordination. However, the synthesis of free-standing AlN nanosheets has been challenging due to the crystal configurations of the well-known bulk AlN, which presents a hexagonal wurtzite structure with a tetrahedral coordination, preventing its exfoliation to obtain nanosheets. Herein, we propose a facile method involving the preparation of layered-structured aluminum carbonitrides, Al5C3N, followed by exfoliation into AlN nanosheets, offering a potential route for producing 2D AlN. The Al5C3N precursor was chemically etched in hydrofluoric acid (HF), breaking the Al-C bonds and exposing the AlN nanosheets. The development of this synthesis method opens up opportunities towards the preparation of 2D AlN and the investigation of its unique properties for applications in sensors and microelectronics.

Two-dimensional aluminum nitride holds promise for advanced applications, yet its synthesis is hindered by the bulk material’s hexagonal wurtzite structure which prevents facile exfoliation. Here, the authors present a method using layered-structured aluminum carbonitrides as precursors and hydrofluoric acid chemical etching to produce AlN nanosheets, paving the way for innovations in sensors and microelectronics.