Nitrogen-doped graphene on a curved nickel surface

• Published in: Carbon (New York) Vol. 183; pp. 711 - 720
• Main Authors: Vilkov, Oleg Yu, Tarasov, Artem V., Bokai, Kirill A., Makarova, Anna A., Muntwiler, Matthias, Schiller, Frederik, Ortega, J. Enrique, Yashina, Lada V., Vyalikh, Denis V., Usachov, Dmitry Yu
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 15.10.2021; Elsevier BV
• Subjects: Carbon; Chemical reactions; Coupling (molecular); Curved crystals; Flat surfaces; Graphene; Graphite; Graphitic nitrogen; N-Graphene; Nickel; Nitrogen; Non-trivial substrate topography; Photoelectric emission; Photoelectrons; Single crystals; Substrates; Vicinal surfaces; Graphitic nitrogen; Curved crystals; Vicinal surfaces; Non-trivial substrate topography; N-Graphene
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2021.07.038

Graphene growth and doping are well studied on flat surfaces of various materials. To further advance the technological implementation of graphene-based systems, fundamental studies need more appropriate model templates, whose surfaces would mimic substrates with non-trivial topography. Here, using electron and photoelectron diffraction and photoemission spectroscopy as well, we demonstrate how a curved tungsten crystal covered by a thin nickel film can properly be used as such platform, allowing the fabrication and comprehensive characterization of nitrogen-doped graphene. We show the way in which nitrogen impurities prefer to embed into the graphene matrix at different areas of the curved metallic surface with variable density of atomic steps. In particular, at atomically flat regions with a strong graphene-metal interaction, pyridinic configuration is the most abundant form of dopants, while graphitic nitrogen strongly dominates in places with a weak coupling of graphene to the substrate, i.e., in the vicinity of the surface irregularities. We recognize single crystals with curvilinear surfaces as versatile platforms for the studies of not only low-dimensional materials, but also molecular adsorption, chemical reactions and catalysis on surfaces with complex structure. [Display omitted] •Configurations of dopants in N-graphene atop a curved Ni substrate are explored.•To study the atomic environment of dopants, photoelectron diffraction is applied.•Pyridinic N is the most abundant form at atomically flat regions.•Graphitic N strongly dominates in the vicinity of the steps.