Exfoliation of Ti₃ C₂ MXene using (NH₄ )₂TiF₆ Etchant and Simultaneous Synthesis of Ti₃ C₂ MXene/NH₄ TiOF₃ Mesocrystals Hybrids

Abstract A new single-step method is suggested to fabricate block structures consisting of NH 4 TiOF 3 wrapped around Ti 3 C 2 MXene (Ti 3 C 2 ) by etching Ti 3 AlC 2 MAX phase with (NH 4 ) 2 TiF 6 . The optimal reaction conditions for Ti 3 AlC 2 MAX phase and (NH 4 ) 2 TiF 6 are systematically investigated. (NH 4 ) 2 TiF 6 selectively etches the Al in the Ti 3 AlC 2 MAX phase and promotes promoting the mild hydrolysis reaction of (NH 4 ) 2 TiF 6 to form NH 4 TiOF 3 crystals. The exterior shapes of Ti 3 C 2 /NH 4 TiOF 3 hybrids can be tuned by adjusting the reagent concentration, reaction temperature. The phase composition, morphology and photophysical properties of the Ti 3 C 2 /NH 4 TiOF 3 hybrids are investigated using various characterization techniques. Ti 3 AlC 2 MAX phase reacts with (NH 4 ) 2 TiF 6 at 60 °C for 24 h to form hybrids which are surrounded by NH 4 TiOF 3 crystals simultaneously with the formation of Ti 3 C 2 nanosheet. The resulting Ti 3 C 2 /NH 4 TiOF 3 are porous and finely structured, showing potential for various applications in biotechnology, sensing, and environmental fields. This method provides important insights into future applications of Ti 3 C 2 /NH 4 TiOF 3 hybrids.