A mild and delamination-free route to long-shelf-life MXenes with enhanced porosity and superior photothermal efficiency

The synthesis of MXenes with high surface area and porosity remains challenging due to reliance on aggressive etchants and delamination step. This work reports a mild and straightforward strategy to synthesize Ti 3 C 2 and Ti 2 C MXenes using a nano-platelet MAX phase precursor prepared via anisotropic molten salt synthesis. This precursor’s unique architecture—featuring a 15× higher surface area and 5× greater pore volume than conventional MAX phases—enables efficient Al removal with dilute hydrofluoric acid (4% HF), eliminating the need for delamination agents or post-etching processing. These MXenes achieve a high specific surface area of 105m 2/g and pore volume of 0.11c m3/g, representing 5- and 3-fold improvements over conventional MXenes. Notably, this work demonstrates the first investigation of MAX phase photothermal properties and establishes a new synthesis paradigm that eliminates delamination requirements while achieving record photothermal conversion efficiency (71.4% for MXene, 63.1% for MAX). The pre-engineered nanoplatelet architecture inherently prevents restacking, enabling stable performance for over 200 days without intercalation agents—addressing a critical limitation in MXene shelf-life and practical applicability.