Improved Singlet Oxygen Production by Synergistic Effect via a Dual-Core Photosensitizer Doped Polymer Fibrous Films:...

Singlet oxygen (¹O₂) is a common reactive oxygen species that has found wide application in wastewater processing, photochemical synthesis, and photodynamic therapy. In this paper, a dual-core metal [a Re(I)-based component and a Gd(III)-based component] photosensitizer was synthesized and doped into polymer fibrous films for ¹O₂ generation. Here the Re(I)-based component is responsible for the photosensitizing reaction which directly transformed ³O₂ to ¹O₂, while the Gd(III)-based component served as an auxiliary part that assisted the transformation from ³O₂ to ¹O₂ via synergistic effect by its triplet excited ligands. The photophysical parameters of this photosensitizer (denoted as Re-Gd) and its fibrous films (denoted as Re-Gd@PVP) were carefully recorded, discussed, and compared. It was found that the excited state lifetime and photostability of Re-Gd were both improved after being doped into fibrous films, favoring ¹O₂ generation. The ¹O₂ generation performance comparison between Re-Gd in the solid state, in solution, and fibrous films suggested that ¹O₂ generation performance was indeed improved by the electrospinning films. In addition, the positive factor of synergistic effect on improving ¹O₂-producing efficiency was confirmed by comparing Re-Gd@PVP films with reference films with a single-core metal photosensitizer having no synergistic effect.