Energy- and cost-efficient NaCl-assisted synthesis of MAX-phase Ti₃AlC₂ at lower temperature

Ti₃C₂, produced by selective etching of Al from MAX-phase Ti₃AlC₂, is the most widely studied two-dimensional MXene material in many research fields. However, the synthesis of highly pure Ti₃AlC₂ typically requires high temperatures, resulting in high-energy demands and high production costs. To reduce the synthesis temperature, we present a new NaCl-assisted approach for synthesizing Ti₃AlC₂. Ti₃AlC₂ was synthesized from a Ti₂AlC–TiC mixture at 1150 °C under an argon atmosphere in a tube furnace. The successful synthesis of highly pure Ti₃AlC₂ with an ideal crystal structure and the subsequent preparation of Ti₃C₂ were confirmed by material characterization and simulation results. This molten-salt-assisted method is more efficient in terms of energy and cost because it lowers the synthesis temperature of MAX-phase Ti₃AlC₂ by 200 °C. When assisted by appropriate kind or quantity of molten-salt, the synthesis temperature and synthesis time may be further reduced. These findings may provide a new approach for lower-temperature synthesis of other MAX-phase materials and greatly widen the applications of MAX and MXene materials.