Surface modified MXene Ti3C2 multilayers by aryl diazonium salts leading to large-scale delamination

Herein we report a simple and facile method to delaminate MXene Ti 3 C 2 multilayers by the assistance of surface modification using aryl diazonium salts. The basic strategy involved the preparation of layered MAX Ti 3 AlC 2 and the exfoliation of Ti 3 AlC 2 into Ti 3 C 2 multilayers, followed by Na + intercalation and surface modification using sulfanilic acid diazonium salts. The resulting chemically grafted Ti 3 C 2 flakes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. Ultraviolet-visible spectroscopy revealed that surface-modified MXene Ti 3 C 2 sheets disperse well in water and the solutions obey Lambert–Beer’s law. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to demonstrate the morphology and structure of delaminating MXene Ti 3 C 2 flakes. The results indicated that chemical modification for MXene multilayers by aryl diazonium salts induced swelling that conversely weakened the bonds between MX layers, hence leading to large-scale delamination of multilayered MXene Ti 3 C 2 via mild sonication. Advantages of the present approach rely not only on the simplicity and efficiency of the delamination procedure but also on the grafting of aryl groups to MXene surfaces, highly suitable for further applications of the newly discovered two-dimensional materials.