High Concentration of Ti₃C₂T_<i>x</i> MXene in Organic Solvent

Abstract

MXenes are currently one of the most widely studied two-dimensional materials due to their properties. However, obtaining highly dispersed MXene materials in organic solvent remains a significant challenge for current research. Here, we have developed a method called the tuned microenvironment method (TMM) to prepare a highly concentrated Ti₃C₂T_<i>x</i> organic solvent dispersion by tuning the microenvironment of Ti₃C₂T_<i>x</i>. The as-proposed TMM is a simple and efficient approach, as Ti₃C₂T_<i>x</i> can be dispersed in <i>N</i>,<i>N</i>-dimethylformamide and other solvents by stirring and shaking for a short time, without the need for a sonication step. The delaminated single-layer MXene yield can reach 90% or greater, and a large-scale synthesis has also been demonstrated with TMM by delaminating 30 g of multilayer Ti₃C₂T_<i>x</i> raw powder in a one-pot synthesis. The synthesized Ti₃C₂T_<i>x</i> nanosheets dispersed in an organic solvent possess a clean surface, uniform thickness, and large size. The Ti₃C₂T_<i>x</i> dispersed in an organic solvent exhibits excellent oxidation resistance even under aerobic conditions at room temperature. Through the experimental investigation, the successful preparation of a highly concentrated Ti₃C₂T_<i>x</i> organic solvent dispersion <i>via</i> TMM can be attributed to the following factors: (1) the intercalation of the cation can lead to the change in the hydrophobicity and surface functionalization of the material; (2) proper solvent properties are required in order to disperse MXene nanosheets well. To demonstrate the applicability of the highly concentrated Ti₃C₂T_<i>x</i> organic solvent dispersion, a composite fiber with excellent electrical conductivity is prepared <i>via</i> the wet-spinning of a Ti₃C₂T_<i>x</i> (dispersed in DMF) and polyacrylonitrile mixture. Finally, various types of MXenes, such as Nb₂CT_<i>x</i>, Nb₄C₃T_<i>x</i>, and Mo₂Ti₂C₃T_<i>x</i>, can also be prepared as highly concentrated MXene organic solvent dispersions <i>via</i> TMM, which proves the universality of this method. Thus, it is expected that this work demonstrates promising potential in the research of the MXene material family.