Functional modulators and missing-linker defects realize high proton conductivity in UiO-66-Hf metal–organic frameworks†

Defects and functional groups on ligands in metal organic frameworks affect porosity and surface area, which successively impacts proton mobility. Defective UiO-66-Hf frameworks with different defect numbers and functional groups were synthesized by adding aromatic monocarboxylic modulators. Thus, an optimal proton conductivity at 4.56 × 10⁻² S cm⁻¹ was achieved, which was four orders of magnitude greater than the original UiO-66-Hf.