One-step synthesis for cations intercalation of two-dimensional carbide crystal Ti3C2 MXene

MXene, a new family of two-dimensional transition metal carbides and/or carbonitride, has been shown to be able to expand the layer spacing through Li+, Na+, etc. intercalation, thus providing ion diffusion channels for lithium-ion/sodium-ion batteries. The semiconductor material Sn-based can also be used as a reasonable choice for intercalation due to its large specific capacity. However, the layer spacing of MXene after cationic intercalation is usually lower than that before intercalation. To increase the layer spacing after cationic intercalation, a one-step method of etching Ti3AlC2 with 49 wt% HF and cationic (Li+, Na+, Sn4+) salt solution was used to prepare cations-intercalated MXene. The structure and morphology before and after intercalation were characterized by XRD and SEM. The results showed that the cations-intercalated Ti3C2 MXene is successfully synthesized through the one-step method, and its layer spacing is larger than that when performing etching followed by intercalation. Etching with HF and Sn4+ caused a maximum increase in the c-lattice parameters of Ti3C2 MXene, from 18.5 to 24.84 Å. Moreover, TEM and XPS confirmed that Sn4+ was homogeneously distributed in the Ti3C2 MXene matrix.