MXene Synthesis in Seconds by Flash Joule Heating

MXenes exhibit exceptional structural and physicochemical properties, enabling them to be applied in a wide range of fields, including energy storage and electromagnetic shielding. However, conventional etching synthesis routes, such as hydrofluoric acid (HF) etching, Lewis acid etching, and molten-salt etching, are limited by long reaction times, high energy consumption, and severe chemical hazards. Here, we developed a rapid, scalable, and environmentally benign approach for MXene synthesis via sequential flash Joule heating-chlorination and fluorination (FJH-ClF). By precisely tuning the thermodynamic and kinetic parameters, diverse high-quality layered MXenes with excellent electrochemical performance were synthesized through the selective removal of interstitial atoms from nine different MAX phases, each within 30 s. This universal FJH-ClF strategy drastically reduces energy and reagent usage, establishing a safe, cost-effective, and sustainable method for next-generation MXene manufacturing.