Coupling confined ion clusters with hydrogen bonds to modulate ion transport

Abstract Hydrogen bonds (H‐bonds) govern ion transport by mediating ion–water interactions. In bulk solvent environments, tailoring ion clusters has proven effective in reconfiguring H‐bond networks to enhance ion mobility. However, under nanoscale confinement, it remains unclear how H‐bond networks and ion transport respond to complex ion clusters driven by intensified cation–anion interactions. Herein, molecular dynamics simulations reveal an ion cluster‐hydrogen bond coupling mechanism under nanoconfinement. Ion clustering stabilizes hydration shells and induces anisotropic rearrangement of H‐bond networks near channel walls, prolonging H‐bond lifetimes and strengthening wall‐parallel bonds that hinder ion mobility. Based on this mechanism, we regulate ion transport by modifying nanochannel surface groups to tune the H‐bond network. Hydrophobic MXene–F exhibits the largest increase in H‐bond lifetime and differences in diffusion coefficients. These insights offer a molecular‐level basis for designing efficient ion transport systems via H‐bond regulation.