Acceleration of the chemical delamination of Ti3AlC2 crystals in the presence of chloroauric acid with the formation of 2D MXenes

A method for accelerated synthesis of 2D MXenes Ti 3 C 2 T x from the MAX phase Ti 3 AlC 2 by selective etching of Al in acidic fluoride-contained solutions in the presence of HAuCl 4 as a catalyst is proposed. The results of characterization of the etching products using scanning and transmission electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and 4-probe resistivity measurements are presented. It is shown that the introduction of HAuCl 4 into the etching solution increases the rate of aluminum removal from the precursor crystals and increases the efficiency of their separation into 2D layers. The mechanism of such acceleration is a transfer of the hydrogen gas release region from the distributed front of aluminum dissolution inside the crystal to the clusters of gold formed on its outer surfaces.