Can polymers do magic? – The role(s) of polymeric templates in light-driven catalysis

Prof. Dr. Felix H. Schacher, Friedrich Schiller University Jena, Germany

Polymers are a versatile class of materials with almost unlimited  combinations of functional groups being present in close proximity. This  in combination with a widely tunable solubility has enabled quite a  range of examples where building blocks for light-driven catalysis (i.e.,  photosensitizers and catalysts) are immobilized using either covalent  anchoring or non-covalent interactions. During recent years, we have  developed different soft matter matrices for either light-driven  hydrogen evolution (HER) or water oxidation (WOC) based on unimolecular  graft copolymers, block copolymer micelles, hydrogels, or nanoporous  block copolymer membranes. In all cases, close proximity of the  immobilized building blocks facilitated light-driven reactivity, but we  also observed additional effects during our studies, such as prolonged  lifetime of photosensitizers, altered degradation pathways, or the  possibility to repair / exchange catalysts or sensitizers. In addition,  some effects imply that – especially in case of polyampholytic graft  copolymers – the polymeric matrix is also involved in charge transport,  presumably due to the high charge density present along the polymer  backbone. Altogether, in this contribution we try to derive some general  guidelines for the design of (charged) soft matter matrices for  light-driven catalysis.