Gogotsi-Yury.pdfCO2 ReductionCO2 Reduction
- 1. -足 1 -足 Two-足dimensional Transi/on Metal Carbides Produced by Exfolia/on of MAX Phases Yury Gogotsi & Michel Barsoum Students: Michael Naguib, Olha Mashtalir, Murat Kurtoglu Drexel University AJ Drexel Nanotechnology Ins7tute Materials Science and Engineering Department Philadelphia, Pennsylvania NSF/AFOSR Workshop on 2D Materials Beyond Graphene, May 30-足31, 2012
- 2. -足 2 -足 2 M X A M Composition of Mn+1AXn ; with n =1,2,3 Ternary metals carbides and/or nitrides Layered hexagonal structure (P63/mmc) Examples: Ti2AlC, Ti2AlN, Ti3AlC2,Ti4AlN3 Ta2AlC, Ta4AlC3 Cr2AlC, Cr3AlC2 V2AlC, V3AlC2 Nb2AlC, Nb4AlC3 (>60 phases) (Ti0.5Nb0.5)2AlC, Ti3Al(C0.5N0.5)2 (considering solid solution, there will be more) Barsoum, M.W. Progress in Solid State Chemistry 28 (2000) 201 281 211 312 413 MAX Phases Strong but Ductile Ceramics - not van der Waals Solids
- 3. -足 3 -足 MAX phase MAX phases are layered ternary carbides, nitrides, and carbonitrides consisJng of M, A, and X layers SelecJve etching only of the A layers from the MAX phase MXene sheets Physically separated 2-足D MXene sheets aOer sonicaJon Summary Schematic of Solution Synthesis
- 4. -足 4 -足 HF T reatment O C H Al Ti Sonica/on Michael Naguib, et al. Advanced Materials 23 (2011) 4248-4253 MAX MAX MXene The Solution Approach to Ti3AlC2 Exfoliation and Dispersion Ti3AlC2 in HF 50% for 2 hours at room temperature, then sonication
- 5. M. Naguib, et al. Advanced Materials 23 (2011) 4248-4253 Ti3AlC2 HF 50% for 2 hours at room temperature After HF treatment, the most intense peak of Ti3AlC2 vanished. XRD after HF treatment matches with DFT simulated Ti3C2(OH)2. Sonication results in weakening the intensity of the peaks (losing the crystalline ordering). XRD Analysis of MAX and MXene
- 6. Raman Spectra of MAX and MXene 100 200 300 400 500 600 700 800 Intensity (I) (II) (IV) (V) (III) (VI) Raman shift (cm-1) Ti3AlC2 HF etched Ti3AlC2 etched in 50% HF for 2 hours at room temperature Raman spectroscopy: 514.5 nm excitation M. Naguib, et al. Advanced Materials 23 (2011) 4248-4253 V. Presser, M. Naguib, et al. J. Raman Spectroscopy 43 (2011) 168-172.
- 7. -足 7 -足 Ti3AlC2 etched in HF 50% for 2 hours at room temperature: 2 袖m M. Naguib, et al. Advanced Materials 23 (2011) 4248-4253 L. M. Viculis, et al., Journal of Materials Chemistry 15 (2005) 974-978. Exfoliated Graphite SEM Images of MXene
- 8. -足 8 -足 Science 2012 Vol. 335, pp 526-527 Peoples choice award for International Science & Engineering Visualization Challenge from NSF, 2012. MXene on the Cover
- 9. -足 9 -足 Ti3AlC2 treated in HF 50% for 2 hours at room temperature, then sonication Michael Naguib, et al. Advanced Materials 23 (2011) 4248-4253 TEM Analysis of Ti3C2
- 10. -足 10 -足 5 nm R<20nm 5 nm Michael Naguib, et al. Advanced Materials 23 (2011) 4248-4253 Ti3AlC2 in 50%-HF for 2 hours at room temperature, then sonication MXene Scrolls/Nanotubes MXene shows behavior typical of graphene or other 2-D materials
- 11. -足 11 -足 4 袖m 3 袖m 1 袖m 2 袖m 1 袖m 1 袖m As received Ti3C2 Ti2C (Ti0.5Nb0.5)2C Ti3(C0.5N0.5 )2 Ta4C3 Michael Naguib, et al. ACS Nano 6 (2012) 1322-1331 MXenes A Large Family of Transition Metal Carbides and/or Nitrides Several MAX phases have been exfoliated, producing MXenes
- 12. -足 12 -足 Michael Naguib, et al. ACS Nano 6 (2012) 1322-1331 40nm 1 2 3 20nm 50nm 50nm Ti3C2 Ti3(C0.5N0.5 )2 (Ti0.5Nb0.5)2C Ta4C3 MXenes A Large Family of Transition Metal Carbides and/or Nitrides
- 13. -足 13 -足 M. Naguib, et al. ACS Nano 6 (2012) 1322-1331 HR TEM and SAD of Ta4C3 1100 0110 1010 1120 1210 2110 5 1/nm 20 nm 1.325 nm 13 2 nm 0.269 nm (0110) 0.155 nm (2110) 60属 Crystalline structure is maintained within the layer MXene layers are in registry in multilayer structures
- 14. -足 14 -足 10袖m 10袖m Ta4C3 flakes Ti3CN Individual (multi)layers are optically transparent under visible light Michael Naguib, et al. ACS Nano 6 (2012) 1322-1331 Light Microscopy of MXenes
- 15. -足 15 -足 Ti3C2(OH)2: OH terminated Ti3C2 nanosheets Ti3C2: Bare layers, no termina/ons Ti3C2F2: F-足terminated Ti3C2 nanosheets Semiconductor (0.05 eV bandgap) Semiconductor (0.1 eV bandgap) Metal M. Naguib, et al. Advanced Materials 23 (2011) 4248-4253 Electronic Structure of MXenes DFT implemented in the CASTEP code in Material Studio software (Version 4.5)
- 16. -足 16 -足 Ti2C Ta4C3 (Ti0.5Nb0.5)2C Ti3(C0.5N0.5)2 R: 330 立/ 104 立/ 171 立/ 125 立/ CA: 32属 41属 31属 27属 Michael Naguib, et al. ACS Nano 6 (2012) 1322-1331 MXene can be cold pressed in the form of thin (300 袖m) free- standing discs. Resistivity is comparable to multi-layer graphene. Contact angle measurements of water showed hydrophilic behavior. 25mm Wetting and Conductivity
- 17. -足 17 -足 0 0.5 1 1.5 2 2.5 0 100 200 300 400 500 Q disch Cycle 1 Q ch Cycle 1 Q disch Cycle 2 Q ch Cycle 2 Q disch Cycle 20 Q ch Cycle 20 Q disch Cycle 25 Q ch Cycle 25 0 0.5 1 1.5 2 Potential (V vs. Li/Li + ) Specific Capacity (mAh揃g -1 ) Number of Inserted Li in the Structure (y) 1st 2nd 20-25 0 100 200 300 400 500 600 0 20 40 60 80 100 120 Data 31 4:08:31 PM 11/30/2011 Q discharg (C/25) Q charg (C/25) Qdischarge (C/6) Qcharge (C/6) Qdischarge (1C) Qcharge (1C/) Qdischarge (3C) Qcharge (3C) Qdischarge (10C) Qcharge (10C) Specific Capacity (mAh揃g -1 ) Cycle Number 0 100 200 300 400 500 600 0 5 10 15 20 Data 31 8:36:44 PM 11/3/2011 Q discharg (C/25) Q charg (C/25) Qdischarge (C/6) Qcharge (C/6) Qdischarge (1C) Qcharge (1C/) Qdischarge (3C) Qcharge (3C) Qdischarge (10C) Qcharge (10C) 3C 1C C/6 C/25 C/6 C/25 1C 3C & 10C 10C Ti2COx based anode properties similar to lithium titanate anodes M. Naguib, et al. Electrochemistry Communications 16 (2012) 61-64 MXene as a Li-足ion Ba[ery Anode
- 18. -足 18 -足 SelecJve etching of A layer from MAX phases results in the formaJon of 2-足D transiJon metals carbides and/or nitrides called MXenes Band gap of MXene predicted to change with the surface chemistry Excellent mechanical properJes predicted (DFT) Su鍖ciently ducJle for cold pressing ConducJvity comparable to mulJ-足layer graphene Hydrophilic (contact angle 30-足40属) Li inserJon allows use in Li-足ion ba[ery anodes Summary of the Data to Date
- 19. -足 19 -足 Electrical energy storage Pseudocapacitors, Lithium ion ba[eries, Hybrid devices Composite materials ConducJve, high-足strength, low-足permeability polymers, high strength and high toughness ceramic-足metal composites Sensors 2-足D and 鍖exible electronics Potential Applications M2X M3X2 M4X3
- 20. -足 20 -足 Acknowledgments J辿r辿my Come & Patrice Simon, Universit辿 Paul Sabatier, Toulouse, France Jun Lu & Lars Hultman, Linkoping University, Sweden Gogotsi Nanomaterials Group Barsoum MAX Phase Group BATT Program