A nonanuclear nickel cluster-based coordination polymer for solar hydrogen production from water in open atmosphere

• A nonanuclear nickel cluster-based CP was synthesized for solar-driven H2production from water with high efficiency and long life.
• The catalyst was able to produce hydrogen in open system under the illumination of sunshine.
• The CV of 1 in air showed little difference as compared to that in inert atmosphere.
• A reductive mechanism was confirmed by the in-situ EPR experiments during the photocatalytic process.

In this work, a novel 2D double-layered metal-organic coordination polymer, [Ni9(Hmna)2(mna)8(H2O)10]·(H2O)11 (1) (H2mna = 2-mercaptonicotinic acid), based on a nonanuclear nickel cluster was synthesized to function as an efficient heterogeneous catalyst with an optimized TON of 685.4 for solar-driven H2 production from water. Both the solar conversion and water utilization were achieved simultaneously in this photocatalytic system. Without the protection of inert atmosphere, the catalyst was still able to produce hydrogen with a TON of 93.5 in air. The influence of oxygen was studied by virtue of cyclic voltammograms (CVs) and UV–vis adsorption spectrum. The active radicals generated in the photocatalytical process were examined by in-situ electron paramagnetic resonance (EPR) experiments which provided solid evidence to support the reductive mechanism.

A novel coordination polymer based on a nonanuclear Ni cluster was synthesized to serve as a heterogeneous catalyst for efficient visible-light-driven H2 production from water half-splitting. The TON can reach up to 685.4 in inert atmosphere and 93.5 in air. Both solar conversion and material transformation were simultaneously realized in this system.Figure optionsDownload as PowerPoint slide