Etching Mechanism of Ti3c2cl2 Mxene Phases by Cucl2-Lewis Molten Salt Method

MXene is a novel type of two-dimensional layered material created by etching various MAX phases. This work describes a method for obtaining fluorine-free Ti3C2Cl2 MXene phases by melting copper in CuCl2 instead of aluminum in Ti3AlC2. XRD results show that when molten salt CuCl2 etches Ti3AlC2, it forms an intermediate product Ti3CuC2, and then reacts with Ti3CuC2 to obtain Ti3C2Cl2. The reaction of Ti3AlC2 and CuCl2 at a temperature of 800 ℃ for 2h to obtain Ti3C2Cl2 with an optimal lamellar structure is shown in SEM results. Moreover, we performed ab initio calculations on the process of the material reactions, indicating the chemical reaction of Ti3AlC2 and CuCl2 will first become Ti3CuC2 and Cu, and then become Ti3C2Cl2 during the Lewis acid etching process, which are consistent with the experimental results.