Facile Solution Processing of Stable MXene Dispersions towards Conductive Composite Fibers.

Shayan Seyedin,Joselito M Razal,Alexey M Glushenkov,Ken Aldren S Usman,Jizhen Zhang,Si Qin,Robert T Jones,Elliard Roswell S Yanza

doi:10.1002/gch2.201900037

Shayan Seyedin, Joselito M Razal + Show 6 more

Open Access

https://doi.org/10.1002/gch2.201900037

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Abstract

2D transition metal carbides and nitrides called “MXene” are recent exciting additions to the 2D nanomaterials family. The high electrical conductivity, specific capacitance, and hydrophilic nature of MXenes rival many other 2D nanosheets and have made MXenes excellent candidates for diverse applications including energy storage, electromagnetic shielding, water purification, and photocatalysis. However, MXene nanosheets degrade relatively quickly in the presence of water and oxygen, imposing great processing challenges for various applications. Here, a facile solvent exchange (SE) processing route is introduced to produce nonoxidized and highly delaminated Ti3C2Tx MXene dispersions. A wide range of organic solvents including methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, dimethyl sulfoxide, chloroform, dichloromethane, toluene, and n‐hexane is used. Compared to known processing approaches, the SE approach is straightforward, sonication‐free, and highly versatile as multiple solvent transfers can be carried out in sequence to yield MXene in a wide range of solvents. Conductive MXene polymer composite fibers are achieved by using MXene processed via the solvent exchange (SE) approach, while the traditional redispersion approach has proven ineffective for fiber processing. This study offers a new processing route for the development of novel MXene‐based architectures, devices, and applications.

Highlights

A recent exciting addition to the 2D (SE) approach, while the traditional redispersion approach has proven family is “MXene” that is derived from ineffective for fiber processing
The details of MXene synthesis can be found in the Supporting Information, where we provided full characterization data that validate the successful etching of aluminum layer, exfoliation of multilayer MXene and delamination into single and few layer MXene
Electron energy loss spectroscopy (EELS) analysis showed prominent peaks at ≈284 and ≈465 eV related to carbon (C K-edge) and titanium (Ti L2,3-edge), respectively, and weak peaks at ≈540 to 550 eV indicating the minimal presence of oxygen (O K-edge) as expected for freshly prepared delamination into single and few layer MXene (dMXene) (Figure 1f)

Summary

Results and Discussion

We synthesized Ti3C2Tx MXene using the LiF/HCl approach.[14]. The details of MXene synthesis can be found in the Supporting Information, where we provided full characterization data that validate the successful etching of aluminum layer, exfoliation of multilayer MXene (mlMXene) and delamination into single and few layer MXene (dMXene). We have carried out the SE process for up to five times (Figure S7a, Supporting Information) and sequentially transferred the SE-dMXene methanol dispersion (transferred initially from water via the SE route) to DMSO (2SE), chloroform (3SE), ethanol (4SE), and acetone (5SE) This 5SEdMXene dispersion showed no evidence of aggregation or oxidation for 28 d. This demonstration clearly shows that the solvent exchange route is an effective method for processing highly delaminated MXene dispersions, which could be integrated with various conventional processes for building functional MXene architectures.

Conclusions

Experimental Section

Conflict of Interest