Fluoride‐Free Synthesis of Two‐Dimensional Titanium Carbide (MXene) Using A Binary Aqueous System

Abstract

Two-dimensional (2D) titanium carbide (Ti₃ C₂ ) is emerging as an important member of the MXene family. However, fluoride-based synthetic procedures remain an impediment to the practical applications of this promising class of materials. Here we demonstrate an efficient fluoride-free etching method based on the anodic corrosion of titanium aluminium carbide (Ti₃ AlC₂ ) in a binary aqueous electrolyte. The dissolution of aluminium followed by in situ intercalation of ammonium hydroxide results in the extraction of carbide flakes (Ti₃ C₂ T_x , T=O, OH) with sizes up to 18.6 μm and high yield (over 90 %) of mono- and bilayers. All-solid-state supercapacitor based on exfoliated sheets exhibits high areal and volumetric capacitances of 220 mF cm^-2 and 439 F cm^-3 , respectively, at a scan rate of 10 mV s^-1 , superior to those of LiF/HCl-etched MXenes. Our strategy paves a safe way to the scalable synthesis and application of MXene materials.