High-yield fabrication of electromechanical devices based on suspended Ti₃C₂T_x MXene monolayers

Abstract

MXenes, two-dimensional transition metal carbides, nitrides, and carbonitrides, are known for their exceptional electronic and mechanical properties. Yet, the experimental efforts toward the realization of MXene-based nanoelectromechanical systems (NEMS) combining...

Synergistic Effect of TiS3 and Ti3C2Tx MXene for Temperature-Tunable p-/n-Type Gas Sensing

“…Ti 3 C 2 T x MXene flakes were prepared using the minimally intensive layer delamination (MILD) method; see the Experimental Section for details. Details of the materials characterization of Ti 3 C 2 T x MXene flakes from similar batches by a variety of techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, ultraviolet–visible (UV–vis) absorption spectroscopy, and various microscopic techniques can be found in our recent publications. − Overall, these characterization results were standard for Ti 3 C 2 T x MXene, so here we only focus on the discussion of the data that are relevant for this sensor study. Notably, Figure b (left) shows an SEM image of the as-synthesized Ti 3 C 2 T x , which demonstrates that the flakes were well exfoliated and over 10 μm in lateral size.…”

Interlayer Incorporation of A-Elements into MXenes Via Selective Etching of A′ from Mn+1A′1–xA″xCn MAX Phases

“…This electrostatic behavior could be facilitated by the presence of wide-bandgap semiconductor SnO x species in the interlayer spaces within the accordions, which hampers the charge sinking from MXene layers. Practically, the electrostatically driven elongation of Sn–Ti 3 C 2 T z accordions by over 100% of their length could provide an interesting platform for MXene-based NEMS devices. − Figure c,d demonstrates SEM images of other Sn-MXene particles showing the same electrostatic behavior and exfoliation of the accordions into thin flakes.…”

“…Despite the use of harsher conditions than those needed for the etching of Ti 3 AlC 2 , the resulting MXene sheets were of very high quality and exhibited improved environmental stability, which we attribute to the effect of Sn modification. Finally, we demonstrate a peculiar electrostatic expansion of the Sn–Ti 3 C 2 T z accordions, which may find interesting applications in MXene-based nano-electromechanical systems (NEMS). − Although we demonstrated the feasibility of the described synthetic approach (Figure b) using Ti 3 Al 0.75 Sn 0.25 C 2 as a model system, the generality of this method should be further investigated in the future with other interesting combinations of A-elements that may potentially include Ir, Cu, Ni, etc. Overall, these results demonstrate that in addition to different combinations of M and X elements in MAX phases, an A-layer also provides opportunities for the synthesis of MXene materials.…”

Metallic Conductivity of Ti3C2Tx MXene Confirmed by Temperature-Dependent Electrical Measurements

“…The sample was then washed and centrifuged until pH 6 was reached and then delaminated into flakes by mild shaking for 15 min. During the washing and delamination steps, the sample was handled very gently to avoid flake tearing. , …”

“…During the washing and delamination steps, the sample was handled very gently to avoid flake tearing. 21,43 Materials Characterization. For TEM characterization, Ti 3 C 2 T x flakes were imaged using a FEI Tecnai Osiris transmission electron microscope equipped with a HAADF detector and an X-FEG high brightness Schottky field emission gun at the accelerating voltage of 200 kV.…”