Synthesis and Characterisation of BNC architectures

This thesis addresses the synthesis and preparation of boron- and nitrogen-doped graphene-like materials (BNC architectures) to meet modern technological demands for flexible, low-cost, and tunable electronic devices. The work combines bottom-up and top-down synthesis approaches to produce large-area BNC materials incorporating covalently nitrogen and boron in the graphene-like lattices.
The first bottom-up strategy employed borazine derivatives as molecular precursors, which were deposited onto metal substrates, UV irradiated to induce a crosslinked network and then thermally converted into the doped graphene-like film. Here, we reported the successful trial with the thiol-terminated borazine precursor. A self-assembled layer was prepared using this precursor, then UV irradiated, and subsequently transformed into BNC films. These films were characterised by XPS and Raman spectroscopy, demonstrated effective n-type doping and were implemented as Pt-free counter electrodes in dye-sensitised solar cells, achieving high power conversion efficiencies under both sunlight and indoor lighting.
A complementary bottom-up strategy involved the thermal cyclotrimerisation of alkyne-functionalised borazine on Au(111), resulting in the formation of a porous hexagonal BNC network. This structure was verified through scanning tunnelling microscopy and XPS, revealing controlled spacing and orientation of borazine units.
The top-down synthesis involved doping reduced graphene oxide flakes with boron and/or nitrogen via wet chemistry and thermal treatment. The resulting materials displayed enhanced thermal stability and clear dopant incorporation, as confirmed by Raman, XPS, and EELS. Together, these strategies advance the design of doped graphene for energy and thermal applications in a more straightforward, cost-effective and scalable approach.