Professor Yury Gogotsi is the Distinguished University Professor and Charles T. and Ruth M. Bach Professor of Materials Science and Engineering at Drexel University. He also serves as Director of the A.J. Drexel Nanomaterials Institute. His research group works on synthesis and surface modification of inorganic nanomaterials, such as 2D carbides, nitrides (MXenes), and nanostructured carbons, as well as nanomaterials for energy, water, and biomedical applications. His work on carbon and carbide nanomaterials with tunable structure and porosity had a significant impact on the field of capacitive energy storage. He has co-authored two books, more than 700 papers in peer-reviewed journals, and edited 14 books. He has been recognized as a Highly Cited Researcher in Chemistry and Materials Science, and as a Citations Laureate by Clarivate Analytics.
Professor Gogotsi has received three honorary doctorates and numerous awards for his research, including the ACS Award in the Chemistry of Materials, ACS Philadelphia Section Award, International Nanotechnology Prize (RUSNANOPrize), Ceramic Prize from the World Academy of Ceramics, European Carbon Association Award, S. Somiya Award from the International Union of Materials Research Societies, Nano Energy award from Elsevier, R&D 100 Award from R&D Magazine (twice) and two Nano 50 Awards from NASA Nanotech Briefs. He has been elected a Fellow of the American Association for Advancement of Science (AAAS), Materials Research Society, American Ceramic Society, the Electrochemical Society, the International Society of Electrochemistry, Royal Society of Chemistry, the World Academy of Ceramics, and the European Academy of Sciences. He also served on the MRS Board of Directors, serves on editorial boards of more than a dozen journals, and is currently an Associate Editor of ACS Nano.
In this interview, I talked to Professor Gogotsi about his early research and how he came to focus on nanostructured carbon materials and their potential applications.
What was your early research on, and how did you eventually come to focus on nanostructured carbon materials and hydrothermal synthesis of carbon nanostructures?
During my Ph.D. study and first post-doc, I worked on high-temperature corrosion and oxidation of structural ceramics based on carbides and nitrides, such as silicon carbide, silicon nitride, boron carbide, and titanium nitride. Those were material considered for high-temperature ceramic engines. When I started my post-doc at the Tokyo Institute of Technology in Japan, I was asked to work on hydrothermal corrosion of silicon carbide composites for nuclear power stations. This was when I discovered that a layer of carbon, not silica, was formed on the surface of silicon carbide fibers upon hydrothermal corrosion. This is how, by accident, I entered the world of nanostructured carbons and hydrothermal synthesis, which later led us to the hydrothermal synthesis of carbon nanotubes, studies of unusual dynamics water confined inside those nanotubes, and other exciting discoveries.
Can you please tell me more about your work with nanostructured carbon materials? What are some recent developments involving your research?
Over the past decade, my research drifted towards 2D carbides and nitrides (MXenes), which we discovered with my Drexel colleague Michel Barsoum and our students almost a decade ago, but which are experiencing tremendous growth now. We organized a virtual conference on MXenes in August 2020, which attracted more than 2000 registered participants. There will be the 3rd International Conference on MXenes in China this October and a Symposium dedicated to MXenes at the Fall MRS meeting. There is certainly an entire MXene community emerging. Actually, our article reporting on a multitude of MXene structures and compositions was published in ACS Nano in 2012. More than 30 stoichiometric MXenes have been reported since that time, and numerous solid solutions have been studied. The number of publications on MXenes has been doubling annually in the past couple of years. ACS Nano alone has already published more than a hundred articles on MXenes. And, of course, new exciting properties are reported (e.g., superconductivity – Dmitri Talapin from U Chicago published this summer in Science), anomalously strong interaction with electromagnetic waves (our papers with Chong Min Koo from KIST in ACS Nano, Advanced Materials and Science this year), etc. This leads to a very large variety of applications.
What are some potential applications of nanostructured carbon materials in the fields of energy and biomedicine? Are there any current and potential applications the public may be familiar with?
Carbon nanomaterials have wound numerous applications in energy (all supercapacitor electrodes, battery anodes, conductive additives to all battery electrodes, etc.). Hundreds of tons of multiwalled carbon nanotubes are used in battery manufacturing, and graphene is entering commercial applications as well, replacing carbon back and activated carbon. Nanostructured carbon materials are present in every lithium-ion battery. However, there are quite a few biomedical applications as well. Especially nanodiamonds are widely explored for imaging and drug delivery applications. They are non-toxic, with the crystal size ranging from 5 to 100 nm. Carbon (activated charcoal) has been used for detoxification and wound drying since ancient times. It’s still the first means used in emergency medicine in case of poisoning. We have learned how to control the pore size in those carbons with Angstrom accuracy to more efficiently adsorb specific toxins. Nanoporous carbon and graphene platelets can also remove cytokines and toxic proteins from blood, which is critical in treating sepsis and may also save patients experiencing a cytokine storm after COVID.
There are also emerging medical applications of MXenes. Photodynamic therapy and theranostic applications of plasmonic MXenes are being explored in dozens of publications. Epidermal electronics and brain electrodes made of titanium carbide MXene outperform gold and other metal electrodes. In my group, we work on MXene sorbents for accelerated dialysis and wearable kidney. Although respiratory symptoms are a key feature of COVID, many people who are hospitalized with COVID-19 also suffer acute kidney injury, a condition that exacerbates patient mortality and may have to be treated through renal replacement therapy. Supplies for dialysis treatment, including dialysate, have run dangerously low in hospitals at the epicenter of the pandemic. MXenes can efficiently and rapidly regenerate dialysate, removing toxins and restoring electrolyte concentrations so that this vital resource remains readily available. In particular, Ti3C2Tx, a two-dimensional transition-metal carbide can efficiently adsorb urea, as well as remove creatinine and uric acid from dialysate.
What are the major challenges facing your field today? What are some things that would help overcome these challenges?
Scaling up the production of nanomaterials in a safe and cost-efficient way is the challenge that our field is facing. It does not necessarily mean tons of material – thin, monolayer MXene, or graphene film may not weigh much, but large-area films of good quality are needed for optical and electronic applications. Some other applications really require ton quantities. However, as experience with the nanotubes shows, it is doable with proper efforts.
What are some directions you would like to see your research move towards? Are there any recent studies or possible collaborations that may help you reach these objectives?
I’d like to further expand the family of MXenes. We published on the synthesis of a first representative of the new subfamily of MXenes with a chemical formula M5C4 in the January 2020 issue of ACS Nano, and we want to make more materials in this system as they have been predicted to have a combination of very attractive properties. We are also exploring solid solutions on M and X sites, substituting elements to finely tune optical, electronic, and electrochemical properties of MXenes.
What do you think is the most interesting and/or important unsolved problem in your field?
The most wonderful thing about 2D nanomaterials is that they can help us to solve all important problems, from providing renewable energy and drinkable water to better healthcare. They are simply the building blocks of future materials and devices—LEGO bricks of nanometer size. We are learning how to make them with amazing accuracy and control their structure, properties, and composition. With MXenes adding a large number of metallic structures to an array of dielectric, semiconducting, and semimetallic materials (oxide, dichalcogenides, etc.), we have a full set of electronic properties to build 2D electronics (printable and affordable). However, there is still a long way to go until we can program self-assembly of complex devices from 2D building blocks.
Have you received any good advice that stuck with you? How has it helped you within your career?
Follow your passion. If you do what you like, you are going to do it well, so you will succeed in your career. Not less important, you will feel happy and enjoy your life because you spend most of the day doing what you love to do.