Facile Electrosynthesis of Ti₃AlC₂ and Its Derived Porous Carbon in Molten Salt

MAX phases and their derived materials (MXenes and CDCs) have received widespread attention because of their unique functional properties. However, the controllable synthesis of MAX phases and their derived powder materials remains challenging, and conventional preparation usually involves high-temperature sintering, mechanical crushing, and acid etching processes. Herein, this paper reports a facile electrochemical strategy for the synthesis of Ti₃AlC₂ powder and its derived carbon (Ti₃AlC₂-CDC) from TiO₂/Al₂O₃/C precursors. In this strategy, the synthesis of Ti₃AlC₂ is achieved through molten salt electrolysis of a TiO₂/Al₂O₃/C cathode directly, and the Ti₃AlC₂-CDC is then prepared through a subsequent molten salt electrochemical etching process. Systematical characterization and analysis of the synthesized Ti₃AlC₂ and Ti₃AlC₂-CDC were conducted, and the results indicate that the Ti₃AlC₂ synthesized by molten salt electrolysis is a micro-size powder, exhibiting a distinct lamellar structure with uniform element distribution. The synthesized Ti₃AlC₂-CDC powder exhibits a high specific surface area of 1268 m² g⁻¹ and excellent hierarchical porosity. As a conceptual demonstration, the energy storage properties of Ti₃AlC₂-CDC as electrode materials for lithium-ion battery (showing a specific capacity of 330 mAh g⁻¹) and sodium-ion battery (showing a specific capacity of 100 mAh g⁻¹) were preliminarily investigated, demonstrating excellent cycle stability in both cases. In summary, this work demonstrates the controllable synthesis of Ti₃AlC₂ and Ti₃AlC₂-CDC, offering advanced technological insights into the advancement of MAX phases and their derived powder materials.