Improving Photocatalytic Activity: Versatile Polyelectrolyte – Photosensitizer Assemblies for Methyl Viologen Reduction

Abstract

AbstractIn this study, we introduce a versatile polyelectrolyte‐photosensitizer self‐assembled system based on non‐covalent interaction showing highly efficient photocatalytic behavior in terms of methyl viologen reduction. The photocatalytic performance of the dendrimer‐dye system under visible light irradiation is modified to be more than 6‐times higher compared to the performance of the pure photosensitizer Rose Bengal. By adjusting the pH the self‐assembled structure can be size‐controlled. At the same time the underlying interaction forces change from mainly electrostatic nature to hydrogen and halogen bonding, a combination of forces reported here for the first time for dendrimer based assemblies. While strong electrostatic interaction of oppositely charged components at low pH hinders catalytic activity, the structure exhibits highly increased efficiency upon structure formation at high pH. Thus, a pH and loading ratio dependent photocatalytic system with potential for efficient solar energy conversion via photocatalysis has been established.