Lundi 11 mars 2019 à 10 heures
Michel W. Barsoum, professeur émérite à Drexel University, Philadelphie, Department of Materials Science and Engineering, (> 450 publications, Facteur d’impact = 80), considéré comme la référence internationale dans le domaine des phases MAX et MXenes, effectuera un séminaire Le 11 mars prochain à 10 h à l’IC2MP en salle UMR. Son exposé portera sur les MXenes, une nouvelle famille de matériaux 2D découvert en 2011, souvent qualifiés d’ « argiles conductrices », et qui sont prometteuses pour de nombreuses applications dont plusieurs sont étudiées à l’IC2MP (stockage de l’énergie, catalyse, électrocatalyse, photocatalyse, traitement de l’eau, biomédical,…).
Titre : Why MXenes?
Over the past couple of years, the number of papers on MXenes – 2D transition metal carbides and nitrides – have grown exponentially. The main goal of my talk is to shed some light on why they have become so popular. In 2011, we showed that by simply immersing MAX phase powders in HF, at room temperature, the A-layers are selectively etched to produce 2D materials that we labeled MXenes to emphasize the loss of the A-group element and their 2D nature. The MAX phases – with the general formula, Mn+1AXn, where n = 1 to 3, M is an early transition metal, A is an A-group (mostly IIIA and IVA) element and X is either C and/or N – were put on the map in 1996 also at Drexel University. Currently there are over 30 distinct MXene compositions and structures with new ones being discovered regularly. Unlike hydrophobic graphene, MXenes are hydrophilic and behave as “conductive clays”, or “2D metals”, a hitherto unknown combination. MXenes such as Ti2C, V2C, Nb2C and Ti3C2 can be used as electrode materials in Li or Na-ion batteries and supercapacitors as well as transparent conductive electrodes, with performances in some cases that are quite impressive. The potential of using MXenes in energy storage, as transparent conductive electrodes, EMI shielding, catalysis, electrocatalysis, water treatment, among many other applications will be highlighted. Lastly, the vast compositional and structural space afforded by this new family of 2D materials will be emphasized.
Prof. Michel W. Barsoum is Distinguished Professor in the Department of Materials Science and Engineering at Drexel University. He is an internationally recognized leader in the area of MAX phases and the 2D solids labeled MXenes. Most recently he also discovered a new mechanism – ripplocations – in the deformation of layered solids. With > 450 refereed publications and an ISI h index of 80, his work has been highly cited. He is an International Fellow of the Royal Swedish Academy of Engineering Sciences, Fellow of the American Ceramic Soc. and the World Academy of Ceramics. He is the author of two books, MAX Phases: Properties of Machinable Carbides and Nitrides and Fundamentals of Ceramics, a leading textbook in his field. In 2000 he was awarded a Humboldt-Max Planck Research Award for Senior US Research Scientists. Since 2008 he has been a visiting professor at Linkoping University in Sweden. He spent his last sabbatical year at Imperial College in London and the Grenoble Institute of Technology in France. In 2017, he was a recipient of a Chair of Excellence from the Nanosciences Foundation in Grenoble.