Two-dimensional MXene Ti3C2 produced by exfoliation of Ti3AlC2

MXene, a new family of 2D materials, possesses excellent electrical conductivity and hydrophilicity. To date, the majority of MXenes are only successfully produced by exfoliating the MAX phases with high concentration hydrofluoric acid (HF). In this study, the 2D MXene Ti3C2 with larger interplanar spacing was successfully obtained by etching Ti3AlC2 with bifluoride (NaHF2, KHF2, NH4HF2) in single-stage process. The morphology, structure and element composition of prepared Ti3C2 samples were characterized by scanning electron smicroscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS). The synthesis mechanism of Ti3C2 was elaborately demonstrated. The possible reaction equations between Ti3AlC2 and different bifluorides were generalized, indicating the formation of hydrosoluble by-products of Na3AlF6, K3AlF6 and (NH4)3AlF6. This work presents a safely effective method to synthesize the 2D nanocrystals MXene. [Display omitted] •A safely effective method to synthesize the 2D MXene Ti3C2 was successfully explored.•The larger interplanar spacing Ti3C2 was obtained by exfoliating Ti3AlC2 with NH4HF2 or KHF2 in single-stage process.•The synthesis mechanism of Ti3C2 was elaborately demonstrated.•The possible reaction equations between Ti3AlC2 and bifluorides were given.