Tailoring Ti3C2TxMXene Flake Sizes for Modified Electrochemical Performance: A Top-down Approach

Introduction: Two-dimensional (2D) materials, such as MXene (Ti3C2Tx), have garnered extensive attention in recent years due to their exceptional performance across various domains. The flake size of Ti3C2Txnotably influences its specific surface area, a pivotal factor in interfacial interactions within electrochemistry.Method: Presently, modifying the flake size of bulk Ti3C2Txtypically involves complex and costly processes, like ultrasonic treatment and isolation. Leveraging the specific preparation principle of MXenes, which involves etching the A layers in precursor MAX phases, a topdown strategy for producing Ti3C2Txflakes of desired sizes, has been proposed in this work. In this approach, precursor Ti3AlC2 particles undergo ball-milling to adjust their size.Result: Through this innovative strategy, dispersions of Ti3C2Txflakes with varying average lateral sizes are generated, enabling an investigation into the impact of lateral size on the electrochemical properties of Ti3C2Txflakes. By controlling the ball milling time for Ti3AlC2powders, the resulting average sizes of Ti3C2Tx(0, 2, 4) are 6.34 µm, 2.16 µm, and 0.96 µm, respectively. Particularly, the Ti3C2Tx(2) electrode, composed of 2.16 µm sheets, demonstrates remarkable performance metrics. It exhibits a high areal capacitance of 845.0 mF/cm2at a scan rate of 5 mV/s, along with a gravimetric capacitance of 244.0 F/g at a current density of 1 A/g.Conclusion: This study presents a facile method to enable mass production of Ti3C2Txwith sheets of varying sizes, addressing both small and large dimensions.