Titel: Exploring surfaces with synchrotron light and scanning tunneling microscopy: from graphene to 2D molecular networks  

Abner de Siervo

Institute of Physics “Gleb Wataghin”- State University of Campinas, 13083-859, Campinas, Brazil

e-mail: asiervo@ifi.unicamp.br

Abstract: Nanomaterials are present in several segments of our modern society, for instance in catalysts, coatings and lubricants, cosmetics and medicines, or in more sophisticated products as for example, different types of sensors, data storage, electronic and photonic devices that have already reached the nanoscale. In fact, many of the interesting properties of the nanomaterials are attributed to the quantum confinement effects due to the reduced size of the particles where the electronic and atomic structures can be very different compared to the respective bulk counterpart. Therefore, if we want to be able to tailor the nanomaterial’s properties, it is import to gain a much better understanding of the atomic and electronic structure at one atomic level. During the last years, our group has worked on the understanding of some 2D surfaces, in particular, graphene as a nanotemplates to grow nanoparticles as well as the growth of 2D organic molecular networks using molecules with nanometer scale as building blocks.     

In this seminar, I will show recent examples of how our group is combing different synchrotron-based techniques, such as x-ray photoemission and absorption spectroscopies as well as photoelectron diffraction with other surface science techniques, for instance, scanning tunneling microscopy, to improve the understanding of nanostructured systems at surfaces. As examples, I will discuss the case of intercalation of different metals on corrugated graphene [1-3] and the diffusion and reactivity of porphyrin molecules on Cu(111) and Ag(111) surfaces [4-6].    

References:

[1] L.H. de Lima et al., Physical Review B 87, 081403(R) (2013).

[2] L.H. de Lima et al., Chemistry of Materials 26 (14), 4172-4177 (2014).

[3] Rodrigo C.C. Ferreira et al., Chemistry of Materials  30 (20), 7201-7210 (2018).

[4] M. Lepper et al., Chem. Commun. 53, 8207-8210 (2017).

[5] M. Lepper et al., Angew. Chem. Int. Ed.. 57, 10074-10079 (2018).

[6] Juan Carlos Moreno-López et al., Chemistry of Materials 2019 31 (8), 3009-3017 (2019)