Hydrogenation-induced superconductivity in 2H-V

We investigated the structural, electronic, dynamical, and superconducting properties of hydrogenated 2H-V2N (V2NH2) using first-principles calculations. The results show that 2H-V2NH2 is dynamically stable and an anisotropic superconductor. Hydrogenation enhances electron-phonon coupling. The electronic states near the Fermi level are dominated by V-3d orbitals. Electron-phonon coupling calculations yield a coupling constant λ = 0.70, originating mainly from low-frequency vibrations of V atoms. Anisotropic Migdal-Eliashberg calculations predict a superconducting critical temperature of 20.2 K, which is comparatively high among theoretically predicted superconducting MXenes and approximately 1.6 times the isotropic Allen-Dynes result (12.8 K ). Our results provide theoretical guidance for the design of MXene superconductors.