Improving Formation Conditions and Properties of <i>h</i>BN Nanosheets Through BaF₂-assisted Polymer Derived Ceramics (PDCs) Technique

• Main Authors: Boitumelo J. Matsoso, Victor Vuillet-a-Ciles, Laurence Bois, Bérangère Toury, Catherine Journet
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Series: Nanomaterials
• Subjects: hbn; pdcs; li3n; borazine; baf2; 2d material
• Online Access: https://www.mdpi.com/2079-4991/10/3/443

Hexagonal boron nitrite (<i>h</i>BN) is an attractive material for many applications such as in electronics as a complement to graphene, in anti-oxidation coatings, light emitters, etc. However, the synthesis of high-quality <i>h</i>BN at cost-effective conditions is still a great challenge. Thus, this work reports on the synthesis of large-area and crystalline <i>h</i>BN nanosheets via the modified polymer derived ceramics (PDCs) process. The addition of both the BaF₂ and Li₃N, as melting-point reduction and crystallization agents, respectively, led to the production of <i>h</i>BN powders with excellent physicochemical properties at relatively low temperatures and atmospheric pressure conditions. For instance, XRD, Raman, and XPS data revealed improved crystallinity and quality at a decreased formation temperature of 1200 &#176;C upon the addition of 5 wt% of BaF₂. Moreover, morphological determination illustrated the formation of multi-layered nanocrystalline and well-defined shaped hBN powders with crystal sizes of 2.74&#8722;8.41 &#177; 0.71 &#181;m in diameter. Despite the compromised thermal stability, as shown by the ease of oxidation at high temperatures, this work paves way for the production of large-scale and high-quality <i>h</i>BN crystals at a relatively low temperature and atmospheric pressure conditions.