Dr. Michel W. Barsoum —Distinguished Professor in the Department of Materials Science & Engineering at Drexel University

“1D Lepidocrocite Titania-based Nanomaterials, Their Diverse Morphologies and Exceptional Properties”

Abstract: Recently, we converted 15 binary and ternary titanium carbides, nitrides, borides, into lepidocrocite-based, 1D, sub-nanometer nanofilaments, NFs, ≈ 5x7 Å in cross-section by reacting them with TMAH aqueous solution at ≈ 85 ° C for tens of hours. One gram of our 1D material spans ≈ 600 million km. Depending on with what, and the order the reaction products are washed, the 1D NFs self-assemble into loose, spaghetti-shaped fibers, ≈ 30 nm in diameter, fully inorganic gels, pseudo 2D or porous mesoscopic particles. In all cases, the fundamental building block is 1D lepidocrocite NFs, ≈ 3 nm long, that self-assemble into the aforementioned morphologies. At this time, we believe that our materials are the only thermodynamically stable 1D NFs in water, with important implications in photo- and chemical catalysis. The production of hydrogen for times of the order of 6 months with production rates an order of magnitude higher than P25, will be discussed. The adsorption of some cations and cationic dyes in some cases outperform high adsorption clays. We also discovered that some common dyes, such as rhodamine 6G and crystal violet, sensitize the 1D NFs which allows for their degradation using only visible light. This is important in this respect because our band gap energy, > 4 eV, of our 1D NFs is a record for titania-based materials due to quantum confinement along two directions.

Biography: 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 more recently the 2D solids labeled MXenes derived from the MAX phases. Most recently he also discovered a new universal mechanism – ripplocation - in the deformation of layered solids. With over 500 refereed publications and a Google h index is 145, his work has been cited >120,000 times. He has been and remains on the Web of Science’s highly cited researchers since 2018. He is a foreign member of the Royal Swedish Society of Engineering Sciences, National Academy of Inventors, fellow of the American Ceramic Soc. and the World Academy of Ceramics. He is the author the books, MAX Phases: Properties of Machinable Carbides and Nitrides and Fundamentals of Ceramics, a leading textbook in his field. In 2020, he was awarded the International Ceramics Prize for basic science by the World Academy of Ceramics. This prize is awarded quadrennially and is one of the highest in his field. The prize was awarded for “… outstanding contribution in opening new horizons in material research and specifically for your pioneering work in MAX phases and their derivatives.”