| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
|
| Presentation Title |
Computationally Guided Synthesis of MXenes by Dry Selective Extraction |
| Author(s) |
Yong-Jie Hu, Ervin Rems, Mark Anayee, Yury Gogotsi |
| On-Site Speaker (Planned) |
Yong-Jie Hu |
| Abstract Scope |
MXenes are a rapidly growing family of two-dimensional (2D) transition metal carbides and nitrides which are promising for various applications. Hydrofluoric acid-based etchants are typically used to synthesize MXenes, leading to mixed surface terminations that impede MXene properties. Herein, we present a computational thermodynamic model with experimental validations to explore the feasibility of fluorine-free synthesis of MXenes with uniform surface terminations by dry selective extraction (DSE) reactions. A range of MXene and respective precursor compositions are systematically screened using first-principles calculations to find candidates with high phase stability and low etching energy. We further demonstrate a thermodynamic model based on the CALculation of PHAse Diagrams (CALPHAD) approach to assess the Gibbs free energy of the DSE reaction and the state of the byproducts as a function of temperature and pressure. Based on the assessment, the optimal synthesis temperature and vapor pressure are predicted and further verified by experiments. |