Since the dicovery of MXenes, they have showed promise in many optical fields, such as transparent electrodes, electrochromic devices, photothermal therapy, etc. In our group, we mainly focus on optical properties of MXenes, which contains in situ UV-Vis spectroscopy, in situ spectroscopic ellipsometry and in situ electromagnetic wave shielding measurement. Our goal is to utilize in situ devices to find the correlation between optical properties and other properties of MXenes.
Many MXene was predicted to have interesting electronic and magnetic properties such as semiconductor behavior or ferromagnetic behavior. In this direction one of our main research activities is on the study of these properties of MXenes. We work on synthesis of MXene with molten salt etching to controlling the surface terminations as well as optimizing the etching process and the intercalating and delamination of molten salt etched MXene. AOur goal is to synthesize MXenes which are predicted to have semiconductor behavior or ferromagnetic behavior.
The unique characters of MXenes, such as tunable surface chemistry, anisotropic electronic conducting, and atom-scale layers, endow MXenes particular electromagnetic functions across the broad electromagnetic spectrum. One of our main research activities is to gain a deep understanding of the interaction mechanisms of MXenes with electromagnetic waves and develop MXenes for various electromagnetic applications, such as electromagnetic interference shielding, wireless communications, thermal management, wearable devices, etc. We also look at the fundamental principles of MXene interaction with high frequency Electro-Magnetic waves and try to address EM functionality of electronics that will be brought on by the IoT revolution.
Shahzad, F., Alhabeb, M., Hatter, C.B., Anasori, B., Hong, S.M., Koo, C.M. and Gogotsi, Y. Electromagnetic interference shielding with 2D transition metal carbides (MXenes). Science 2016, 353 (6304), 1137-1140.
Sarycheva, A., Polemi, A., Liu, Y., Dandekar, K., Anasori, B. and Gogotsi, Y. 2D titanium carbide (MXene) for wireless communication. Science Advances 2018, 4 (9), eaau0920.
Han, M., Yin, X., Hantanasirisakul, K., Li, X., Iqbal, A., Hatter, C.B., Anasori, B., Koo, C.M., Torita, T., Soda, Y. and Zhang, L. Anisotropic MXene Aerogels with a Mechanically Tunable Ratio of Electromagnetic Wave Reflection to Absorption. Advanced Optical Materials 2019, 7 (10), 1900267.
Iqbal, A., Shahzad, F., Hantanasirisakul, K., Kim, M.K., Kwon, J., Hong, J., Kim, H., Kim, D., Gogotsi, Y. and Koo, C.M., 2020. Anomalous absorption of electromagnetic waves by 2D transition metal carbonitride Ti3CNTx (MXene). Science 2020, 369 (6502), 446-450.
Han, M., Shuck, C.E., Rakhmanov, R., Parchment, D., Anasori, B., Koo, C.M., Friedman, G. and Gogotsi, Y., 2020. Beyond Ti3C2T x: MXenes for electromagnetic interference shielding. ACS Nano 2020, 14 (4), 5008-5016.
The advantage of MXenes over other classes of 2D materials is their diverse chemistry. Like other nanomaterials, the properties of MXenes are heavily dependent on their surface chemistry. The surface termination groups on MXenes (e.g., -OH, -O, -Cl, F) strongly determine the interactions between MXenes and their environment in addition to modulating their electronic, mechanical, and chemical reactivity. Applications of MXenes, such as EMI shielding, catalysis, antimicrobial protection, and chemical adsorption, are dependent on controlling the surface chemistry among other parameters. Additionally, the surface termination groups allow for MXenes to be readily incorporated into a variety of materials such as textiles. There are several methods to modulate the surface termination groups either during the etching process (e.g., mixed-acid vs HF, molten salt, halogenation) or by post synthetic chemical treatment. We seek to investigate the effects of surface termination groups on chemical gas adsorption and degradation using MXene textile composites.
Raman spectroscopy has proved to be one of the most useful tools for analyzing two-dimensional materials. The systematic studies of Ti3C2 MXene Raman spectra revealed differences in composition, surface groups, intercalated species and stacking based on the synthesis and deposition methods. This opened new avenues for using Raman spectroscopy to analyze the whole family of MXenes and made this technique a regularly used tool to determine the quality and degradation of produced materials. The discovery of surface plasmon resonance in Ti3C2 initiated the recent efforts in surface-enhanced Raman scattering (SERS). In the last few years, numerous publications have explored Ti3C2 MXene for sensitive detection of organic pollutants, disease molecules, and typical SERS probe molecules. Recently, six more MXenes have proven to possess SERS capabilities, showing that a wide choice of MXenes could be provided for biomedical, environmental, and biological SERS sensors. Finally, tip-enhanced Raman spectroscopy (TERS) investigation on MXene allowed nanoscale spectroscopic characterization of Ti3C2Tx from a single to a few layers, which further increases the capabilities of using Raman spectroscopy with MXenes.
A. Sarycheva, Y. Gogotsi. Raman spectroscopy analysis of the structure and surface chemistry of Ti3C2Tx MXene. Chemistry of Materials 2020 32 (8), 3480-3488
K. Shevchuk, A. Sarycheva, Y. Gogotsi. Evaluation of two-dimensional transition-metal carbides and carbonitrides (MXenes) for SERS substrates. MRS Bulletin 2022
Leading Group members: Meikang Han, Teng Zhang, Danzhen Zhang, Roman Rakhmanov, Robert Lord, Kateryna Shevchuk, Adam Goad