Pure &crystallized 2D Boron Nitride sheets synthesized via a novel process coupling both PDCs and SPS methods.

Sheng Yuan,Sébastien Linas,Vincent Garnier,Arnaud Brioude,Bérangère Toury,Philippe Steyer,Guillaume Bonnefont,Catherine Journet

doi:10.1038/srep20388

Abstract

Within the context of emergent researches linked to graphene, it is well known that h-BN nanosheets (BNNSs), also referred as 2D BN, are considered as the best candidate for replacing SiO2 as dielectric support or capping layers for graphene. As a consequence, the development of a novel alternative source for highly crystallized h-BN crystals, suitable for a further exfoliation, is a prime scientific issue. This paper proposes a promising approach to synthesize pure and well-crystallized h-BN flakes, which can be easily exfoliated into BNNSs. This new accessible production process represents a relevant alternative source of supply in response to the increasing need of high quality BNNSs. The synthesis strategy to prepare pure h-BN is based on a unique combination of the Polymer Derived Ceramics (PDCs) route with the Spark Plasma Sintering (SPS) process. Through a multi-scale chemical and structural investigation, it is clearly shown that obtained flakes are large (up to 30 μm), defect-free and well crystallized, which are key-characteristics for a subsequent exfoliation into relevant BNNSs.

Highlights

Thanks to their remarkable potential for electronic applications, 2D-nanomaterials related researches are currently booming
Exfoliation is well-documented in the literature and can be performed by mechanical[16,20,21,22,23,24] or chemical[25,26,27,28,29,30,31,32,33,34,35] methods. This indirect way for generating BN nanosheets (BNNSs) by exfoliation from high quality hexagonal boron nitride (h-BN) crystals seems more relevant, but suffers from a lack of pure h-BN sources of supply, as discussed above. Keeping this issue in mind, we propose an innovative alternative experimental procedure, which can be widely applied to produce important amount of h-BN flakes with large-scale (> 10 μ m) and high purity based on an original combination of two advanced techniques: the Polymer Derived Ceramics (PDCs) route, and the Spark Plasma Sintering (SPS) process
A preliminary characterization of the chemical bonding within the specimen is investigated by X-ray photoelectron spectroscopy (XPS)

Summary

Introduction

Thanks to their remarkable potential for electronic applications, 2D-nanomaterials related researches are currently booming. The first one consists in a direct deposition of the required BNNSs on a substrate, while the second one is based on the generation of BNNSs by exfoliation of large h-BN single crystals.

Results

Conclusion