Simple Approach to Enhance Long-Term Environmental Stability of MXene Using Initiated Chemical Vapor Deposition Surface Coating

Abstract

Developing a methodology to enhance long-term stability is one of the most important issues in MXene research, since they are prone to oxidation in the ambient environment. Although various approaches have been suggested to improve the stability of MXene, they have suffered from complicated processes and limited applicability to various types of MXene nanostructures. Herein, we report a simple and versatile technique to enhance the environmental stability of MXenes. Ti3C2T x MXene films were decorated with a highly hydrophobic polymer, 1H,1H,2H,2H-perfluorodecyl methacrylate (PFDMA), using initiated chemical vapor deposition (iCVD) where iCVD allows the facile postdeposition of polymer films of desired thickness on MXene films. The oxidation resistance was evaluated by fabricating MXene gas sensors and measuring the change in signal-to-noise ratio (SNR) of volatile organic compound (VOC) gases under harsh conditions (RH 100% at 50 °C) for several weeks where the performance in the absence and presence of PFDMA was compared. The results show that while the SNR of PFDMA-Ti3C2T x sensors was retained, a dramatic increase of the noise level and a decrease in the SNR were observed in pristine Ti3C2T x . We believe that this simple and nondestructive method will offer great potential to enhance the stability of a wide range of MXenes.

Materials-Driven Soft Wearable Bioelectronics for Connected Healthcare

“…MXenes are emerging TMCs/TMNs with a 2D “honeycomb-like” lattice and have been an active topic for soft and stretchable electronics over the past decade since they were first synthesized in 2011. − M n +1 X n T x is the general chemical formula of MXene where M is a transition metal (including Ti, Zr, Hf, W, Nb, Ta, Cr, etc. ), X means carbon or nitride with n = 1–3, and T x represents surface terminal functional groups such as fluorine (-F), hydroxyl (-OH), or oxygen (-O) .…”

Advancements in MXene-based composites for electronic skins

“…60–63 In an impressive study, an adaptable technique was introduced for improving the environmental durability of MXenes. 64 Accordingly, MXene (Ti 3 C 2 T x ) films were coated with a highly hydrophobic polymer called 1 H ,1 H ,2 H ,2 H -perfluorodecyl methacrylate (PFDMA) using initiated chemical vapor deposition, allowing for the easy application of polymer films with desired thickness onto MXene films. To assess the resistance to oxidation, MXene gas sensors were fabricated and the change in signal-to-noise ratio (SNR) of volatile organic compound gases was measured under harsh conditions (RH 100% at 50 °C) over several weeks.…”

“…The results indicated that while the SNR of PFDMA-MXene sensors remained intact, pristine MXene exhibited a significant increase in noise level and decrease in SNR, providing an uncomplicated and nondestructive approach for enhancing the stability of various MXenes. 64…”

MXene Fibers for Flexible and Wearable Electronics: Recent Progress and Future Perspectives

“…High-quality MXenes can also be obtained under appropriate conditions using chemical vapor deposition by placing the substrate and feedstock in a reaction chamber. [19] Xu et al prepared high-quality, large-area ultrathin orthorhombic Mo 2 C crystals (α-Mo 2 C) using copper-catalyzed-chemical vapor deposition. [20] By effectively controlling the growth temperature and growth time, α-Mo 2 C crystals with thicknesses of a few nanometers and lateral dimensions over 100 μm can be obtained.…”