A self-sensitized Co (II)-MOF for efficient visible-light-driven hydrogen evolution without additional cocatalysts

Herein, a new metal-organic framework (MOF) {[Co(azpy) (bps) (H2O)]·DMF·2.3H2O}n, 1, (azpy ​= ​4,4′-azopyridine, H2bps ​= ​4, 4′- bibenzoic acid-2, 2′-sulfone (H2bps) has been synthesized by solvothermal method. Complex 1 was characterized in detail by X-ray single-crystal diffraction, elemental analysis, IR spectrum, PXRD and thermogravimetric analysis. X-ray single-crystal diffraction analysis for 1 indicates that two azpy ligands bearing unusual cis-configuration bridge two Co2+ cations, forming an interesting one-dimensional nanopore channel. And these nanopore channels finally form a three-dimensional framework by multiple π···π stacking interactions. Besides, visible-light-driven H2 production exhibited that complex 1 displayed a high-efficiently photocatalytic hydrogen generation (1.44 ​mmol ​g−1·h−1) without additional photosensitizers and cocatalysts. Moreover, the photocurrent response of 1, solid-state UV–Vis absorption spectra of 1 and free ligands were also explored.