Integrating local polarization in hydrogen bonded organic frameworks for efficient photocatalytic nitrogen fixation

Elaborately designing stabilized hydrogen-bonded organic frameworks (HOFs) with higher charge transfer rate and abundant active sites for efficient photocatalytic nitrogen fixation are urgent and challenging. Herein, a micromolecular hydrogen-based triazole unit integrated into rigid perylene diimide based hydrogen-bonded organic framework (NPDI) has been elaborately designed. Experimental and theoretical results demonstrate that the flexibility and polar micromolecular group embedded in rigid framework not only stabilized HOFs frameworks, but also enhanced the local polarization, electron delocalization and the built-in electric field of HOFs, which greatly promotes exciton dissociation and the carrier transfer. Fortunately, NPDI has excellent photocatalytic nitrogen fixation rate (179 µmol h−1 g−1) and near-infrared NH4+ yield in pure water under ambient conditions. Our work offers deep insights into molecular level regulation for rationally designing efficient HOFs.