Efficient visible-light-induced hydrogenation over composites of CdS and ruthenium carbonyl complexes

•Ru carbonyl complex/CdS composites show visible-light-driven activity for hydrogenation of carbonyl compounds.•Irradiation mode, sacrificial agent, and the structure of Ru complexes influence the performance.•CdS act as photosensitizer, while Ru-based complex is active electro-catalyst for hydrogenation.•A mechanism of the photocatalytic hydrogenation over the hybrid systems was proposed.

Hybrid systems built by coupling CdS with a series of Ru carbonyl complexes ([Ru(bpy)2(CO)2](PF6)2 (RC-1), [Ru(phen)2(CO)2](PF6)2 (RC-2), [Ru(bpy)(CO)2Cl2] (RC-3), [Ru(Me2bpy)(CO)2Cl2] (RC-4), and [Ru(phen)(CO)2Cl2] (RC-5)) showed activity for the hydrogenation of carbonyl compounds under visible-light irradiations in the presence of appropriate sacrificial agent. The influences of the irradiations mode, sacrificial agent, substrates, and the structure of the Ru complexes on the hydrogenation performance of these composites were investigated. Results indicated that CdS act as the photosensitizer, while the Ru carbonyl complexes as catalytic active component. This study provides some guidance in the development of feasible hybrid photocatalytic systems encompassing visible-light-responsive semiconductors and redox-active transition metal complexes, which are expected to find great potentials in the photocatalytic organic transformations. It is believed that such photocatalytic systems can be built in a more controllable way based on our understanding on the structure–activity relationship of the molecular electro-catalyst.

Graphical abstractHybrid photocatalytic systems by coupling CdS (as photosensitizer) with a series of Ru complexes (as active electro-catalyst) showed activity for hydrogenation of carbonyl compounds under visible-light irradiations.Figure optionsDownload full-size imageDownload high-quality image (74 K)Download as PowerPoint slide