Step-by-Step Guide for Synthesis and Delamination of Ti₃ C₂ T_x MXene

To advance the MXene field, it is crucial to optimize each step of the synthesis process and create a detailed, systematic guide for synthesizing high-quality MXene that can be consistently reproduced. In this study, a detailed guide is provided for an optimized synthesis of titanium carbide (Ti₃ C₂ T_x ) MXene using a mixture of hydrofluoric and hydrochloric acids for the selective etching of the stoichimetric-Ti₃ AlC₂ MAX phase and delamination of the etched multilayered Ti₃ C₂ T_x MXene using lithium chloride at 65 °C for 1 h with argon bubbling. The effect of different synthesis variables is investigated, including the stoichiometry of the mixed powders to synthesize Ti₃ AlC₂ , pre-etch impurity removal conditions, selective etching, storage, and drying of MXene multilayer powder, and the subsequent delamination conditions. The synthesis yield and the MXene film electrical conductivity are used as the two parameters to evaluate the MXene quality. Also the MXenes are characterized with scanning electron microscopy, x-ray diffraction, atomic force microscopy, and ellipsometry. The Ti₃ C₂ T_x film made via the optimized method shows electrical conductivity as high as ≈21,000 S/cm with a synthesis yield of up to 38 %. A detailed protocol is also provided for the Ti₃ C₂ T_x MXene synthesis as the supporting information for this study.