Enabling Heteroatom Doping of Flexible MXene Film in Seconds: A Microwave‐Induced Targeted Thermal‐Shock Method

Abstract Heteroatom doping can efficiently tailor the physicochemical properties of 2D MXene materials for enhancing the energy storage performance. However, in mostly applied doping strategies, the wet chemistry method typically suffers tedious separation and abstersion process while the solid‐phase thermal strategy (traditional furnace heating) employed long‐time （several hours） high‐temperature treatment may cause degradation of MXene. In this work, a universal, energy efficient and environmental‐friendly strategy is reported to realize the heteroatom doping of MXene within seconds by microwave‐induced targeted thermal shock. The MXene film can self‐heat to >800 °C within seconds followed by generating dazzling plasma under microwave field. The high temperature combined with plasma create a localized ultrahigh‐energy environment in MXenes, which promotes the rapid decomposition of preloaded dopant precursors and lattice/surface functional group substitutions between dopant atoms and MXene. The resulted nitrogen (N) and sulfur (S) co‐doped MXene showed significantly improved capacity and performance stability under deformations. Compared with the traditional furnace heating, the targeted heating strategy have significantly higher energy and time efficiencies and reduced carbon footprint. In addition, this method can be readily extended to various element doping of MXene. The microwave‐induced targeted thermal‐shock represents a general and efficient strategy for the fast heteroatom doping of MXene.