Il giorno Martedì 10 Novembre 2026 alle ore 14:00 presso la "Sala Montalcini" dell'Istituto Italiano di Tecnologia IIT (via Morego 30, Genova)  il Dr. Tarcísio M. Perfecto ( Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil)  terrà un Seminario dal titolo : 

“Defects in 2D Materials: What TEM Can, and Cannot, Show”

Abstract

Missing sulfur atoms are thought to switch on the inert basal plane of MoS₂, turning it into an active catalyst for hydrogen evolution. Atomic-resolution electron microscopy should be the ideal tool to find them. So why is it so hard?

In this seminar, I will take a critical look at what (S)TEM can, and cannot, prove about defects in 2D materials, using defect-engineered MoS₂ as a test case. I will show how hydrocarbon contamination compromises atomic-resolution data and present the plasma-free protocol that consistently gave us clean lattices. Multislice simulations show that single sulfur defects drop below our detection limit in flakes only three layers thick, and that a sulfur vacancy and an oxygen substitution produce nearly indistinguishable contrast. Rather than stopping at what we cannot see, I will focus on what can be measured with confidence from images and diffraction: edges, terraces and pores, local phases and strain, and short-range order from electron pair distribution function (ePDF) analysis.

I will close with a new challenge we are starting with colleagues in Genoa: extending these lessons to sustainable, bamboo-derived electrodes modified with MoS₂. The talk is aimed at anyone who synthesizes, images or models 2D materials, and includes a brief introduction to the electron microscopy facilities at LNNano, part of CNPEM, the Brazilian research center that hosts the Sirius synchrotron.

 Referente Difar  Prof. Omar Ginoble Pandoli  omar.ginoblepandoli@unige.it