Fluoride‐Free Synthesis of 2D Titanium Carbide (MXenes) Assisted by scCO2‐Based Ternary Solution

Abstract

Abstract2D MXene‐Ti3C2Tx holds great promise in various electronic applications, especially for electromagnetic interference (EMI) shielding devices and supercapacitors. Ti3C2Tx synthesis typically involves the use of hazardous fluorine‐containing chemicals that can result in the formation of inert fluoride functional groups on the surface of Ti3C2Tx, severely degrading its properties and posing a threat to the performance of electron transfer among electrical devices. Herein, a supercritical carbon dioxide‐based ternary solution (scCO2/DMSO/HCl) to produce fluoride‐free Ti3C2Tx in mild conditions (via 0.5 m HCl, 20 MPa, 32 °C) is reported. The fluorine‐free Ti3C2Tx films electrode presents an excellent gravimetric capacitance of 320 F g−1 at 2 mV s−1 in 1 m H2SO4. Besides, it is demonstrated that fluorine‐free Ti3C2Tx films exhibit outstanding EMI shielding efficiency of 53.12 dB at 2.5 µm thickness. The findings offer a mild and practical approach to producing fluoride‐free Ti3C2Tx and open opportunities for exploring MXenes’ potential applications in various fields.