"Room-Temperature Synthesis of 2D Ti₃C₂T_x MXene Nano-sheets via Organic Base Treatment for Rechargeable Alkali-Metal Battery Electrodes"

In this work, we present a cost-effective synthesis of the novel two-dimensional (2D) multilayered Ti₃C₂T_x MXene nanosheets by intercalating tetramethylammonium (TMA⁺) ions at room-temperature via manual shaking, instead of using ultra-sonication methods. The TMAOH organic solvent weakens the interlayer bonds and the intercalated TMA⁺ ions expands interlayer spacing by interacting with surface functional groups (-O, -OH, -F). The XRD data confirms successful synthesis of MXene (Ti₃C₂T_x) nano-sheets via its characteristic planes (002) and/or c-lattice expansion from 18.8 to 29.4Å. A morphological study obtained by SEM revealed the perfect layered structure of Ti₃C₂T_x, while EDX results shows Al removal and reduced F-content after TMAOH treatment. X-ray photoemission (XPS) data aligning with EDX study enlightens a slightly different surface composition with respect to the bulk. High-resolution Ti2p core-level spectra recorded for the compounds allow us to understand the nature of chemical bonding in all samples. Electrochemical testing with Lithium (Li⁺), Sodium (Na⁺), and Potassium (K⁺) under identical conditions shows ion-size-dependent behavior. Voltage profile analysis revealed distinct behaviors, with Li⁺ and K⁺, highlighting different energy storage mechanisms. This work offers novel contributions to understanding MXene' potential for energy storage applications.