On-Surface Carbon Nitride Growth from Polymerization of 2,5,8-Triazido‑s‑heptazine

• Published in: Chemistry of materials Vol. 35; no. 17; pp. 6762 - 6770
• Main Authors: Krinninger, Matthias, Bock, Nicolas, Kaiser, Sebastian, Reich, Johanna, Bruhm, Tobias, Haag, Felix, Allegretti, Francesco, Heiz, Ueli, Köhler, Klaus, Lechner, Barbara A. J., Esch, Friedrich
• Format: Journal Article
• Language: English
• Published: American Chemical Society 12-09-2023
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.3c01030

Carbon nitrides have recently come into focus for photo- and thermal catalysis, both as support materials for metal nanoparticles as well as photocatalysts themselves. While many approaches for the synthesis of three-dimensional carbon nitride materials are available, only top-down approaches by exfoliation of powders lead to thin-film flakes of this inherently two-dimensional material. Here, we describe an in situ on-surface synthesis of monolayer 2D carbon nitride films as a first step toward precise combination with other 2D materials. Starting with a single monomer precursor, we show that 2,5,8-triazido-s-heptazine can be evaporated intact, deposited on a single crystalline Au(111) or graphite support, and activated via azide decomposition and subsequent coupling to form a covalent polyheptazine network. We demonstrate that the activation can occur in three pathways, via electrons (X-ray illumination), via photons (UV illumination), and thermally. Our work paves the way to coat materials with extended carbon nitride networks that are, as we show, stable under ambient conditions.