TiO_2@Perylene Diimide Full-Spectrum Photocatalysts via Semi-Core-Shell Structure

摘要

A semi-core-shell structure of perylene diimide (PDI) self-assembly coated with TiO_2 nanoparticles is constructed, in which nanoscale porous TiO_2 shell is formed and PDI self-assembly presented 1D structure. A full-spectrum photocatalyst is obtained using this structure to resolve a conundrum-TiO_2 does not exhibit visible-light photocatalytic activity while PDI does not exhibit ultraviolet photocatalytic activity. Furthermore, the synergistic interaction between TiO_2 and PDI enables the catalyst to improve its ultraviolet, visible-light, and full-spectrum performance. The interaction between TiO_2 and PDI leads to formation of some new stacking states along the Π-Π stacking direction and, as a consequence, electron transfer from PDI to TiO_2 suppresses the recombination of e~-/h~+ and thus improves photocatalytic performance. But the stronger interaction in the interface between TiO_2 and PDI is not in favor of photocatalytic performance, which leads to rapid charge recombination due to more disordered stacking states. The study provides a theoretical direction for the study of core-shell structures with soft materials as a core, and an idea for efficient utilization of solar energy.