How to Increase the h-BN Crystallinity of Microfilms and Self-Standing Nanosheets: A Review of the Different Strategies Using the PDCs Route

Crystals

Stéphane Benayoun¹  Sébastien Linas²  Arnaud Brioude²  Catherine Journet²  Bérangère Toury²  Sheng Yuan²  Philippe Steyer³  Vincent Garnier³ 

[1] Laboratoire de Tribologie et Dynamique des Systèmes, Ecole Centrale de Lyon, F-69130 Ecully, France;Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, Université de Lyon, LYON1, F-69622 Villeurbanne, France;Matériaux Ingénierie et Science, UMR CNRS 5510, INSA de Lyon, Université de Lyon, F-69621 Villeurbanne, France;

关键词: h-BN;    PDCs;    2D nanolayers;    coatings;    nanosheets;   

DOI  :  10.3390/cryst6050055

来源: DOAJ

【 摘 要 】

Hexagonal boron nitride (h-BN) is a well-known material whose use is almost restricted to lubricating applications in domains ranging from metallurgy to cosmetics. Howover, h-BN displays many other interesting properties, opening new perspectives for other engineering applications, such as as a solid lubricant in aeronautics, as the perfect substrate to graphene for electronic devices, etc. However, all these promising developments require tailored h-BN shapes displaying a high level of crystallization, ensuring its properties for the long term. Here, we developed three strategies, all associated with the Polymer Derived Ceramics (PDCs) route, to prepare highly crystallized supported thick coatings and self-standing nanosheets. The first strategy concerns the innovative implementation of a Rapid Thermal Annealing to prepare micrometric h-BN coatings on thermal sensitive substrates. Compared to conventional treatment the crystallization of h-BN has successfully lowered to about 300 °C. The second strategy consists of an additivation of the used polymer precursor. Effect of lithium nitride as a crystallization promoter was investigated lowering the onset crystallization temperature from 1400 °C (traditionally) to 1000 °C. This novel synthetic route allows preparing self-standing highly crystallized h-BN nanolayers. Finally, the third strategy is based on a unique combination of the PDCs route with Spark Plasma Sintering to profit of both approaches. This original method leads to large and well-crystallized flakes available for a subsequent exfoliation.

【 授权许可】

Unknown