Self-assembly of a cobalt(II)-based metal–organic framework as an effective water-splitting heterogeneous catalyst for light-driven hydrogen production

The solar photocatalysis of water splitting represents a significant branch of enzymatic simulation by efficient chemical conversion and the generation of hydrogen as green energy provides a feasible way for the replacement of fossil fuels to solve energy and environmental issues. We report herein the self-assembly of a Co II -based metal–organic framework (MOF) constructed from 4,4′,4′′,4′′′-(ethene-1,1,2,2-tetrayl)tetrabenzoic acid [or tetrakis(4-carboxyphenyl)ethylene, H 4 TCPE] and 4,4′-bipyridyl (bpy) as four-point- and two-point-connected nodes, respectively. This material, namely, poly[(μ-4,4′-bipyridyl)[μ 8 -4,4′,4′′,4′′′-(ethene-1,1,2,2-tetrayl)tetrabenzoato]cobalt(II)], [Co(C 30 H 16 O 8 )(C 10 H 8 N 2 )] n , crystallized as dark-red block-shaped crystals with high crystallinity and was fully characterized by single-crystal X-ray diffraction, PXRD, IR, solid-state UV–Vis and cyclic voltammetry (CV) measurements. The redox-active Co II atoms in the structure could be used as the catalytic sites for hydrogen production via water splitting. The application of this new MOF as a heterogeneous catalyst for light-driven H 2 production has been explored in a three-component system with fluorescein as photosensitizer and trimethylamine as the sacrificial electron donor, and the initial volume of H 2 production is about 360 µmol after 12 h irradiation.