Materials Science & Engineering Colloquium
Date: February 12, 2016 from 11:00 am to 12:00 pm EST
Location: Columbia University
Morningside Campus
Room 214 S.W. Mudd
Contact: For further information regarding this event, please contact Chris A. Marianetti by sending email to chris.marianetti@columbia.edu or by calling 212-854-9478.
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Two-Dimensional Carbides:
Synthesis, Properties and Applications


Yury Gogotsi

Department of Materials Science and Engineering, and A. J. Drexel Nanomaterials Institute,
Drexel University, Philadelphia, PA 19104, USA; nano.materials.drexel.edu

 

Two-dimensional (2D) solids - the thinnest materials available to us - offer unique properties and a potential path to device miniaturization. The most famous example is graphene, which is an atomically thin layer of carbon atoms bonded together in-plane with sp2 bonds. In 2011, an entirely new family of 2D solids - transition metal carbides (V2C, Ti3C2, Nb4C3, etc.) and nitrides - were discovered by Drexel University scientists [1]. Selective etching of the A-group element from a MAX phase results in formation of 2D Mn+1Xn solids, labeled "MXenes". 17 different 2D carbides and carbonitrides have been reported to date [2-5]. A new sub-family of multi-element ordered MXenes was discovered recently [2]. Structure and properties of numerous MXenes have been predicted by the density functional theory, showing that MXenes can be metallic or semiconducting, depending on their composition, structure and surface termination. Their elastic constants along the basal plane are expected to be higher than that of the binary carbides. Oxygen or OH terminated MXenes, are hydrophilic, but electrically conductive (up to 6000 S/cm). Hydrazine, urea, amines and other polar organic molecules can intercalate MXenes leading to an increase of their c lattice parameter [3]. Colloidal solutions of single- and few-layer MXene flakes can be used to manufacture MXene films with controllable optical and electronic properties. One of the many potential applications for 2D Ti3C2 is in electrical energy storage devices such as batteries, Li-ion capacitors and supercapacitors [3-6]. Cations ranging from Na+ to Mg2+ and Al3+ intercalate MXenes. Ti3C2 paper electrodes, produced by vacuum assisted filtration of an aqueous dispersion of delaminated Ti3C2, show a higher capacity than graphite anodes and also can be charged/discharged at significantly higher rates. They also demonstrate very high intercalation capacitance (up to 1000 F/cm3) [5].

1.     M. Naguib, et al, Advanced Materials,  23 (37), 4207-4331 (2011)

2.     B. Anasori, et al, ACS Nano, 9 (10), 9507-9516 (2015)  

3.     O. Mashtalir, et al, Nature Communication, 4, 1716 (2013)

4.     M. R. Lukatskaya, et al, Science, 341 (6153), 1502-1505 (2013)

5.     M. Ghidiu, et al, Nature, 516, 78-81 (2014)

6.     M. Naguib, Y. Gogotsi, Accounts of Chemical Research, 48 (1), 128-135 (2015)

 

Biography: Yury Gogotsi is Distinguished University Professor and Trustee Chair of Materials Science and Engineering at Drexel University. He is the founding Director of the A.J. Drexel Nanomaterials Institute and Associate Editor of ACS Nano. He works on nanostructured carbons and two-dimensional materials for energy related and biomedical applications. His work on synthesis of carbon and carbide nanomaterials with tunable structure and porosity had a strong impact on the field of capacitive energy storage. He has co-authored 2 books, more than 400 journal papers and obtained more than 50 patents. He has received numerous national and international awards for his research. He was recognized as Highly Cited Researcher by Thomson-Reuters in 2014 and 2015, and elected a Fellow of AAAS, MRS, ECS, RSC and ACerS, and a member of the World Academy of Ceramics.

Host: Yuan Yang