Multifunctional Polyoxometalate-Platforms for Supramolecular Light-driven Hydrogen Evolution

Abstract

Multifunctional supramolecular systems are a central research topic in light-driven solar energy conversion. Here, we report a polyoxometalate (POM)-based supramolecular dyad, where two platinum-complex hydrogen evolution catalysts are covalently anchored to an Anderson polyoxomolybdate anion. Supramolecular electrostatic coupling of the system to an iridium photosensitizer enables visible light-driven hydrogen evolution. Combined theory and experiment demon-strate the multifunctionality of the POM, which acts as photosensitizer / catalyst-binding-site and facilitates light-induced charge-transfer and catalytic turnover. Chemical modification of the Pt-catalyst site leads to increased hydrogen evolution reactivity. Mechanistic studies shed light on the role of the individual components and provide a molecular understanding of the interactions which govern stability and reactivity. The system could serve as a blueprint for multifunctional polyoxometalates in energy conversion and storage.

Latest progress in covalently modified polyoxometalates-based molecular assemblies and advanced materials

“…The variation of the linkage structure caused fundamental changes in the excited-state topology of the dyads and orders of magnitude changes in the intramolecular electron transfer rates and excited-state lifetimes [65] . Pt(II)-complex were also used to covalent attach with Anderson-type platform-POMs for HER [66] . The results showed that POMs acted as PS-and catalyst-binding sites, facilitating electron transfer under irradiation.…”

Insights into the different mechanistic stages of light-induced hydrogen evolution of a 5,5′-bisphenanthroline linked RuPt complex

“…As shown in several previous reports, replacement of the chloride ligands by iodide ligands typically enhances lightinduced hydrogen evolution in Pt-based systems. 19,48,49 For instance, Kaufhold et al 48 showed that the addition of an iodide salt to the photocatalytic system can activate a platinum center during photocatalysis by in situ ligand exchange leading to improved H 2 formation.…”

Bi‐Functional On‐Surface Molecular Assemblies Predicted From a Multifaceted Computational Approach

“…This work is therefore relevant to the growing area of molecular spintronics, as well as the important topic of structure prediction for molecular materials in general. While bifunctional and multifunctional molecular assemblies have been reported in the experimental literature previously, [ 29,30 ] the prediction of a bifunctional assembly entirely from computation appears to be a first.…”