The NSF Public Access Repository (PAR) system and access will be unavailable from 5:00 PM ET until 8:00 PM ET on Friday, September 11 due to maintenance. We apologize for the inconvenience.
Explore Research Products in the PAR It may take a few hours for recently added research products to appear in PAR search results.
This content will become publicly available on November 1, 2026
Title: Rapid Electrothermal Heating and Molten Salt Etching to Produce Ti 3 C 2 MXenes
Rapid, out‐of‐oven techniques for MXene synthesis are of great interest and would allow for easier production of this exciting class of 2D materials. MXenes are typically synthesized by etching MAX phases with strong acids for long times, sometimes exceeding 40 h. Electrothermal synthesis techniques can reduce the heating time of materials; here Joule heating with molten salt etching precursors is utilized to etch MAX phase into multilayered (ML) Ti3C2Tx MXenes. An inert environment is used to etch the MAX phase in 30 min at 750–800 °C. SEM/EDS and XRD confirmed etching of the material. XPS, FTIR, and Raman are compared to conventional LiF‐HCl ML‐ Ti3C2Tx, showing similar spectra to Joule heated ML‐Ti3C2Tx material. Most importantly, this new out‐of‐oven Ti3C2Tx synthesis decreased etching time by 98% from molten salt etching and reduced energy usage from 1.56 × 107to 1.01 × 106J g−1per batch, paving the way for the commercialization of MXene etching. more »« less
Rigby, Maxwell T.; Natu, Varun; Sokol, Maxim; Kelly, Daniel J.; Hopkinson, David G.; Zou, Yichao; Bird, James R.; Evitts, Lee J.; Smith, Matt; Race, Christopher P.; et al
(, RSC Advances)
null
(Ed.)
Quaternary MAX phases, (Ta 1−x Ti x ) 3 AlC 2 ( x = 0.4, 0.62, 0.75, 0.91 or 0.95), have been synthesised via pressureless sintering of TaC, TiC, Ti and Al powders. Via chemical etching of the Al layers, (Ta 0.38 Ti 0.62 ) 3 C 2 T z – a new MXene, has also been synthesised. All materials contain an M-layer solid solution of Ta and Ti, with a variable Ta concentration, paving the way for the synthesis of a range of alloyed (Ta,Ti) 3 C 2 T z MXenes with tuneable compositions for a wide range of potential applications.
Limbu, Tej B.; Chitara, Basant; Orlando, Jason D.; Garcia Cervantes, Martha Y.; Kumari, Shalini; Li, Qi; Tang, Yongan; Yan, Fei
(, Journal of Materials Chemistry C)
Transition metal carbides (MXenes) are an emerging family of highly conductive two-dimensional materials with additional functional properties introduced by surface terminations. Further modification of the surface terminations makes MXenes even more appealing for practical applications. Herein, we report a facile and environmentally benign synthesis of reduced Ti 3 C 2 T x MXene (r-Ti 3 C 2 T x ) via a simple treatment with l -ascorbic acid at room temperature. r-Ti 3 C 2 T x shows a six-fold increase in electrical conductivity, from 471 ± 49 for regular Ti 3 C 2 T x to 2819 ± 306 S m −1 for the reduced version. Additionally, we show an enhanced oxidation stability of r-Ti 3 C 2 T x as compared to regular Ti 3 C 2 T x . An examination of the surface-enhanced Raman scattering (SERS) activity reveals that the SERS enhancement factor of r-Ti 3 C 2 T x is an order of magnitude higher than that of regular Ti 3 C 2 T x . The improved SERS activity of r-Ti 3 C 2 T x is attributed to the charge transfer interaction between the MXene surface and probe molecules, re-enforced by an increased electronic density of states (DOS) at the Fermi level of r-Ti 3 C 2 T x . The findings of this study suggest that reduced MXene could be a superior choice over regular MXene, especially for the applications that employ high electronic conductivity, such as electrode materials for batteries and supercapacitors, photodetectors, and SERS-based sensors.
Abstract Surface chemistry and core composition of 2D MXenes play a major role in their interfacial properties, but the determination and quantification of their bonding environments remain challenging. X‐ray Photoelectron Spectroscopy (XPS) is a method of choice that is broadly utilized but is often hindered by large uncertainties and systematic bias due to adsorbed species such as adventitious carbon or etching residues. In this work, energy‐dependent XPS and depth profile modeling of the Ti3C2TxMXene surface are employed to differentiate the contributions from the MXene and the adsorbed species, thereby increasing the accuracy of quantification. In comparison, uncorrected lab‐based XPS suffers from a systematic overestimation of Ti vacancies by 7% and an underestimation of terminal atoms, particularly F, by as much as 15%. Interestingly, it is found that a simple inelastic mean free path correction is sufficient to address the issue and reveals extremely low defects in Ti3C2TxMXene synthesized using the HF/HCl etching route. Soft X‐ray Absorption Spectroscopy (XAS), supported by Density Functional Theory (DFT) calculations, also demonstrates a high chemical sensitivity of the surface terminations. This work provides novel insights into XPS quantification and the use of XAS for probing the carbide core and surface chemistry of Ti3C2TxMXenes.
Shamsabadi, Ahmad A.; Fang, Hui; Zhang, Danzhen; Thakur, Anupma; Chen, Cindy Y.; Zhang, Aixi; Wang, Haonan; Anasori, Babak; Soroush, Masoud; Gogotsi, Yury; et al
(, Small Methods)
Abstract MXenes, a family of 2D transition‐metal carbides and nitrides, have excellent electrical conductivity and unique optical properties. However, MXenes oxidize in ambient conditions, which is accelerated upon heating. Intercalation of water also causes hydrolysis accelerating oxidation. Developing new tools to readily characterize MXenes’ thermal stability can enable deeper insights into their structure–property relationships. Here, in situ spectroscopic ellipsometry (SE) is employed to characterize the optical properties of three types of MXenes (Ti3C2Tx, Mo2TiC2Tx, and Ti2CTx) with varied composition and atomistic structures to investigate their thermal degradation upon heating under ambient environment. It is demonstrated that changes in MXene extinction and optical conductivity in the visible and near‐IR regions correlate well with the amount of intercalated water and hydroxyl termination groups and the degree of oxidation, measured using thermogravimetric analysis. Among the three MXenes, Ti3C2Txand Ti2CTx, respectively, have the highest and lowest thermal stability, indicating the role of transition‐metal type, synthesis route, and the number of atomic layers in MXene flakes. These findings demonstrate the utility of SE as a powerful in situ technique for rapid structure–property relationship studies paving the way for the further design, fabrication, and property optimization of novel MXene materials.
Abstract MXenes are among the fastest‐growing families of 2D materials, promising for high‐rate, high‐energy energy storage applications due to their high electronic and ionic conductivity, large surface area, and reversible surface redox ability. The Ti3C2TxMXene shows a capacitive charge storage mechanism in diluted aqueous LiCl electrolyte while achieving abnormal redox‐like features in the water‐in‐salt LiCl electrolyte. Herein, variousoperandotechniques are used to investigate changes in resistance, mass, and electrode thickness of Ti3C2Txduring cycling in salt‐in‐water and water‐in‐salt LiCl electrolytes. Significant resistance variations due to interlayer space changes are recorded in the water‐in‐salt LiCl electrolyte. In both electrolytes, conductivity variations attributed to charge carrier density changes or varied inter‐sheet electron hopping barriers are detected in the capacitive areas, where no thickness variations are observed. Overall, combining thoseoperandotechniques enhances the understanding of charge storage mechanisms and facilitates the development of MXene‐based energy storage devices.
Pas, Savannah E, Banavath, Ramu, Dujovic, Milos, Radovic, Miladin, Lutkenhaus, Jodie L, and Green, Micah J. Rapid Electrothermal Heating and Molten Salt Etching to Produce Ti 3 C 2 MXenes. Retrieved from https://par.nsf.gov/biblio/10696269. Advanced Materials Interfaces 12.22 Web. doi:10.1002/admi.202500355.
Pas, Savannah E, Banavath, Ramu, Dujovic, Milos, Radovic, Miladin, Lutkenhaus, Jodie L, & Green, Micah J. Rapid Electrothermal Heating and Molten Salt Etching to Produce Ti 3 C 2 MXenes. Advanced Materials Interfaces, 12 (22). Retrieved from https://par.nsf.gov/biblio/10696269. https://doi.org/10.1002/admi.202500355
Pas, Savannah E, Banavath, Ramu, Dujovic, Milos, Radovic, Miladin, Lutkenhaus, Jodie L, and Green, Micah J.
"Rapid Electrothermal Heating and Molten Salt Etching to Produce Ti 3 C 2 MXenes". Advanced Materials Interfaces 12 (22). Country unknown/Code not available: Wiley. https://doi.org/10.1002/admi.202500355.https://par.nsf.gov/biblio/10696269.
@article{osti_10696269,
place = {Country unknown/Code not available},
title = {Rapid Electrothermal Heating and Molten Salt Etching to Produce Ti 3 C 2 MXenes},
url = {https://par.nsf.gov/biblio/10696269},
DOI = {10.1002/admi.202500355},
abstractNote = {Rapid, out‐of‐oven techniques for MXene synthesis are of great interest and would allow for easier production of this exciting class of 2D materials. MXenes are typically synthesized by etching MAX phases with strong acids for long times, sometimes exceeding 40 h. Electrothermal synthesis techniques can reduce the heating time of materials; here Joule heating with molten salt etching precursors is utilized to etch MAX phase into multilayered (ML) Ti3C2Tx MXenes. An inert environment is used to etch the MAX phase in 30 min at 750–800 °C. SEM/EDS and XRD confirmed etching of the material. XPS, FTIR, and Raman are compared to conventional LiF‐HCl ML‐ Ti3C2Tx, showing similar spectra to Joule heated ML‐Ti3C2Tx material. Most importantly, this new out‐of‐oven Ti3C2Tx synthesis decreased etching time by 98% from molten salt etching and reduced energy usage from 1.56 × 107to 1.01 × 106J g−1per batch, paving the way for the commercialization of MXene etching.},
journal = {Advanced Materials Interfaces},
volume = {12},
number = {22},
publisher = {Wiley},
author = {Pas, Savannah E and Banavath, Ramu and Dujovic, Milos and Radovic, Miladin and Lutkenhaus, Jodie L and Green, Micah J},
}
Warning: Leaving National Science Foundation Website
You are now leaving the National Science Foundation website to go to a non-government website.
Website:
NSF takes no responsibility for and exercises no control over the views expressed or the accuracy of
the information contained on this site. Also be aware that NSF's privacy policy does not apply to this site.