Reasonable establishment of organic ligand defect onto two-dimensional zeolite imidazole framework-leaf shape (ZIF-L) for enhanced photocatalytic hydrogen production

Defect engineering is crucial for optimizing the band structures and charge separation of photocatalysts. Herein, the quantity and distribution (core/shell) of organic ligand defects in leaf-shaped zeolite imidazole framework (ZIF-L) composites were modulated via a multi-step method. VZ-12@ZIF-L (with 12 % 1-vinylimidazole in the core) exhibited the highest carrier separation efficiency and the strongest driving force for the hydrogen evolution reaction (HER), achieving a hydrogen evolution rate of 443.19 μmol·h⁻¹ ·g⁻¹ . This rate is 1.81 times that of VZ-25@ZIF-L (with a high defect quantity) and 1.40 times that of ZIF-L@VZ-12 (with defects in the shell). Mechanistically, core defects facilitated the transport of photogenerated carriers, while shell defects narrowed the band gap. Notably, the impact of carrier transport capacity on photocatalytic activity was more significant than that of light absorption. This study provides new insights for the design of efficient defect-engineered metal-organic frameworks (MOFs).