Hydrogenation-induced superconductivity in two-dimensional Nb2N

Abstract

Two-dimensional (2D) superconductors exhibit broad application prospects. However, most 2D materials do not possess intrinsic superconductivity. Therefore, how to induce superconductivity in 2D materials without intrinsic superconductivity has become a research hotspot. Among MXene materials, Nb2N has great functionalization potential, making it an ideal platform for exploring induced superconductivity. In this work, we investigate the superconducting properties of hydrogenated 1T- and 2H-Nb2N MXenes based on the first-principles calculations and Eliashberg theory. Both 1T-Nb2N and 2H-Nb2N do not possess superconductivity, but hydrogenation can induce superconductivity in both phases. Among the hydrogenated phases, H1-Nb2NH2 exhibits the highest superconducting critical temperature (Tc) of 19 K. Detailed analysis of the electronic structure, phonon dispersion, and electron–phonon coupling (EPC) reveals that the Nb-d orbitals dominate the electronic states near the Fermi level. Importantly, hydrogenation not only introduces high-frequency phonon modes but also significantly enhances the EPC strength, especially in the low-frequency acoustic branches. Our findings suggest that hydrogenation is a promising approach for designing novel 2D superconducting materials.