BN Flakes on MWCNTs: Oxford researchers unravel growth mechanism
Illustration of the formation mechanism of boron nitride flakes on multi wall carbon nanotubes
A team from Oxford's departments of Materials and Chemistry, and the Diamond Lightsource, has revealed how hexagonal boron nitride (h-BN) flakes form on multi-wall carbon nanotubes (MWCNTs), creating a heterostructure with exceptional thermal properties. Published in Small (2025)*, the study combines chemical vapour deposition (CVD) synthesis with advanced characterisation and molecular dynamics simulations.
The team demonstrates a two-step growth process: coaxial boron nitride nanotubes (BNNTs) first form around the CNT core, followed by stress-induced buckling and cracking that nucleate h-BN flakes. "Our work provides the first direct evidence of how BN flakes emerge from BN nanotubes under stress. This insight is crucial for designing advanced nanostructures" says Tonghan Liu, a final year DPhil student and first author.
High-resolution STEM, EELS, and XPS analyses confirmed that CNT and BN interact via van de Waals forces, preserving their intrinsic properties. "This non-covalent interface is key" notes Dr Barbara Maciejewska, "because it allows us to combine the strengths of both materials without compromise". Professor Nicole Grobert adds "by integrating chemical synthesis with materials modelling, we open new pathways for tailored nanomaterials that address real-world challenges in electronics and energy".
This interdisciplinary work paves the way for next-generation solutions in thermal management and energy storage.
