Size Selection and Size‐Dependent Optoelectronic and Electrochemical Properties of 2D Titanium Carbide (Ti₃C₂T_x) MXene

Abstract

In stark contrast to bottom-up synthesis, LPE is relatively easy, highly scalable, and produces dispersion of 2D nanosheets in liquids that are ready for solution-processing. However, 2D materials produced via LPE have limited lateral size and usually consist of nanosheets with various lateral flakes sizes and thicknesses. [1,6] Because

Rational Design of Ti3C2Tx MXene Inks for Conductive, Transparent Films

“…In general, for films produced from large-sized 2D flakes, this number can be much lower compared to films fabricated from small-sized 2D flakes at a given thickness, leading to much higher electrical conductivity in the former. 40 This highlights the importance of MXene flake size, in particular for TCEs which typically encounter percolation problems in the highly transparent region. In addition, the degree of Ti 3 C 2 T x flake delamination and aggregation will affect the quantity of interflake tunnelling barriers.…”

Large‐Area Smooth Conductive Films Enabled by Scalable Slot‐Die Coating of Ti3C2Tx MXene Aqueous Inks

“…Impressively, as the most widely studied MXene, Ti 3 C 2 T x possesses the highest conductivity (≈24 000 S cm −1 ) [11] in all solution-processed 2D materials films reported so far, rendering Ti 3 C 2 T x MXene as quite promising TCE material. It is worth noting that flake size matters in realizing the high-performance TCEs; [21] small-sized Ti 3 C 2 T x flakes (<1 µm) leads to the presence of abundant junctions and correspondingly dramatically increased R s in the high transmittance region (>80%), [22] which significantly deviates from the (R s , T) dataset fitting curves according to Equation 1, [23] known as the percolation problems.…”

“…Impressively, as the most widely studied MXene, Ti 3 C 2 T x possesses the highest conductivity (≈24 000 S cm −1 ) [ 11 ] in all solution‐processed 2D materials films reported so far, rendering Ti 3 C 2 T x MXene as quite promising TCE material. It is worth noting that flake size matters in realizing the high‐performance TCEs; [ 21 ] small‐sized Ti 3 C 2 T x flakes (<1 µm) leads to the presence of abundant junctions and correspondingly dramatically increased R s in the high transmittance region (>80%), [ 22 ] which significantly deviates from the ( R s , T ) dataset fitting curves according to Equation 1, [ 23 ] known as the percolation problems. $$\[ \begin{array}{*{20}{c}}{{\rm{T}} = {{\left( {1 + \frac{{188.5}}{{{{\rm{R}}_{\rm{s}}}}}\frac{{{\sigma _{op}}}}{{{\sigma _{DC}}}}} \right)}^{ - 2}}}\end{array} \]$$where σ op is the optical conductivity, σ DC is the DC conductivity, figure of merit (FOM e ) is defined as the ratio of σ DC /σ op for evaluating optoelectronics performance.…”

Size‐Dependent Electrochemistry of Oxygenated Ti3C2Tx MXenes

“…For example, the films fabricated using large MXene nanoflakes possessed higher electrical figures of merit, due to the presence of less inter-flake contacts that impede charge transport across the films. [17] On the other hand, the smaller flakes offer higher electrochemical performance as they enable better electrolyte accessibility to more active sites. [18,19] Interestingly, an electrode fabricated using a mixture of the large and small MXene nanoflakes exhibited the optimal electrochemical performance.…”