Ab initio study of chemically designed de 2D carbon-based networks

PhD Program

Speaker

Sara Lois Cerdera

When

2025/04/14
10:30

Place

CFM Auditorium, Donostia / San Sebastián

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PhD Thesis defense by Sara Lois Cerdera

Supervisors: Aran Garcia-Lekue (DIPC, Ikerbasque Reserach Professor) and Ane Sarasola (UPV/EHU)

Condensed Matter Physics

2D nanomaterials have broad applications in electronics and energy storage, but their prominence in chemical sensing and catalysis is especially notable. Among all, carbon-based materials are particularly promising due to their exceptional properties, tunability, and environmental compatibility. A comprehensive understanding of their properties remains a challenge that cannot be fully addressed through experimental techniques alone. Therefore, integrating experimental and theoretical approaches is essential. This thesis employs density functional theory (DFT) to theoretically explore the catalytic properties of selected carbon-based 2D nanomaterials. In the first place, the performance of graphene doped with tri-coordinated oxygen atoms towards a critical process in fuel cells, the oxygen reduction reaction (ORR), is investigated. Next, we propose an alternative doping strategy aimed at achieving identical and homogeneously distributed doping sites. In particular, we consider using nanoporous graphene as a template and filling its pores with s-triazine or borazine, thus yielding graphene doped with N and B atoms. DFT calculations reveal that these doped membranes significantly enhance the CO2 reduction reaction (CO2RR), demonstrating superior catalytic performance than pristine graphene. Finally, scanning tunneling microscopy (STM) and DFT simulations are combined are used to analyze the self-assembly of one molecule, 4,7-dibromobenzo[c]-1,2,5-thiadiazole (2Br-BTD), into two networks on the Au(111) surface. This study highlights the role of electrostatic interactions in stabilizing non-covalent molecular assemblies on surfaces, emphasizing their synergistic effects. This is particularly relevant to this thesis, as non-covalent bonds demonstrate high responsiveness to external stimuli, enabling potential catalytic or sensing applications. Thus, by integrating theoretical modeling with experimental insights, this thesis advances the understanding of 2D carbon-based nanomaterials for catalytic and sensing applications. The findings will contribute to the rational design of next-generation materials with enhanced performance in sustainable energy and nanotechnology.