Active repair of a dinuclear photocatalyst for visible-light-driven hydrogen production

The molecular apparatus behind biological photosynthesis retains its long-term functionality through enzymatic repair. However, bioinspired molecular devices designed for artificial photosynthesis, consisting of a photocentre, a bridging ligand and a catalytic centre, can become unstable and break down when their individual modules are structurally compromised, halting their overall functionality and operation. Here we report the active repair of such an artificial photosynthetic molecular device, leading to complete recovery of catalytic activity. We have identified the hydrogenation of the bridging ligand, which inhibits the light-driven electron transfer between the photocentre and catalytic centre, as the deactivation mechanism. As a means of repair, we used the light-driven generation of singlet oxygen, catalysed by the photocentre, to enable the oxidative dehydrogenation of the bridging unit, which leads to the restoration of photocatalytic hydrogen formation.

Automated summary

The molecular apparatus of biological photosynthesis can repair itself, while artificial photosynthetic devices can break down when their components are compromised. This study demonstrates the active repair of an artificial photosynthetic molecular device, leading to the restoration of catalytic activity. Hydrogenation of the bridging ligand was identified as the deactivation mechanism, which was repaired through the light-driven generation of singlet oxygen.