Nitride MXenes Beyond Carbides: Bridging the Gap Between Computational Prediction and Experimental Realization

ABSTRACT

Two‐dimensional transition‐metal nitride MXenes represent a promising yet largely unrealized branch of the MXene family. Compared with carbide analogues, they exhibit stronger M–N bonding, distinct surface chemistry, and lattice‐nitrogen‐mediated reaction pathways. Despite extensive computational predictions of thermodynamically viable compositions, only a limited number of nitride MXenes have been experimentally realized, revealing a persistent gap between theoretical design and laboratory synthesis. This review examines this disparity by linking nitride MAX‐phase stability, selective A‐layer removal, nitrogen retention, and phase verification. Nitride MAX phases occupy narrow thermodynamic stability windows relative to competing binary nitrides, while conventional fluoride‐based etching often fails to selectively remove the A layer without destabilizing the M–N framework. Elevated‐temperature processing further promotes nitrogen loss and competing‐phase formation. Recent advances in molten‐salt, Lewis‐acidic, electrochemical, ammoniation, and vapor‐phase synthesis routes are critically evaluated according to the mechanistic barriers they address. Particular attention is given to structural validation because layered morphology alone does not establish MXene formation. To bridge the computational‐experimental gap, we propose a multidimensional workflow integrating precursor stability, bonding descriptors, environment‐dependent etching thermodynamics, kinetic selectivity, surface termination evolution, and iterative experimental feedback. These perspectives establish synthesis and validation priorities required to transform nitride MXenes into reproducible, application‐relevant two‐dimensional nitrides.