Engineering Mo ₂ TiC ₂ T x MXene Electrocatalyst via Metal‐Ion Intercalation Toward Efficient Hydrogen Evolution Reaction

Developing highly efficient, stable, and low‐cost nonprecious metal electrocatalysts for the hydrogen evolution reaction (HER) is critical for scalable green hydrogen production. Herein, we designed a powerful metal ion intercalation strategy to fabricate high‐performance MXene‐based HER catalysts. Systematic studies on Mo 2 TiC 2 T x (T x = O, OH, F) intercalated with Co 2+ , Mn 2+ , and Ni 2+ ions reveal that all three intercalants could induce interlayer expansion to expose active sites. Further in‐depth investigation reveals that the incorporation of Ni 2+ in the Mo 2 TiC 2 T x forms NiOMo bonds, creating a strong electronic interaction that drives charge transfer from Ni atoms to Mo and O atoms. This results in an electron‐rich Mo 2 TiC 2 T x surface, thereby enhancing its catalytic activity. As a result, the optimal 1 mM Ni 2+ ‐Mo 2 TiC 2 T x catalyst yields exceptional HER performance in 0.5 M H 2 SO 4 , requiring an overpotential of only 93 mV to achieve 10 mA cm −2 and demonstrating remarkable stability over 700 h of continuous operation, which confirms its high activity and excellent durability. This article proposes an innovative strategy for designing MXene‐based catalysts through the synergistic control of interlayer spacing and electronic structure.