Tunable Surface Chemistry of Molten Salt Derived MXenes for Data-Driven Electrochemical Materials Discovery

The surface chemistry of MXenes is a central factor governing electrochemical performance and has become increasingly complex with the emergence of molten salt etching routes. Compared with conventional fluoride-derived systems, molten salt derived MXenes exhibit chemically diverse and highly tunable surface states arising from termination chemistry, retained metal species, interfacial evolution, and post-synthetic regulation. Such synthesis-dependent complexity creates a strongly coupled design space that motivates data-driven discovery. In this review, we summarize recent progress in molten salt derived MXenes with emphasis on tunable surface chemistry and its implications for data-driven design. Surface termination engineering, metal incorporation, heterostructure formation, and post-synthetic modification are discussed as interconnected surface-regulation pathways. We further examine how synthesis history, surface chemistry, and electronic structure can be translated into physically meaningful descriptors for machine learning and high-throughput modeling. Overall, this review establishes a chemistry-informed framework linking molten salt synthesis, tunable surface chemistry, and data-driven discovery toward electrochemical applications.