2.2 Preparation of MXene nanosheets
In this study, monolayer or multilayer Ti3C2TX(ML-Ti3C2TX, MXene) was obtained by mild selective etching of the Al layer in Ti3AlC2 (MAX) by HCl and LiF using commercial Ti3AlC2 powder with 200 mesh as a precursor. The MXene nanosheet solution was prepared in accordance with our previous work for subsequent membrane assembly.42 The schematic diagram of the fabrication process of Ti3C2TX MXene nanosheets is shown in Figure 1A.