Abstract
We present novel titanium-porphyrinic gels (TPGs) and titanium-porphyrinic aerogels (TPAs), in which porphyrinic ligand tetrakis(4-carboxyphenyl)porphyrin is coordinated to Ti-oxo clusters. These hierarchically porous TPAs, with micro-, meso-, and macropores and reactant-concentration-dependent Brunauer-Emmett-Teller surface areas of 407–738 m2 g−1, are prepared by CO2 critical point drying of TPGs. Although the Ti4+ → Ti3+ photoreduction of TPAs is less efficient than that of crystalline microporous Ti-porphyrinic framework DGIST-1, prompt diffusion of O2 and spin-trapping agents into the TPA pores causes the rapid generation of reactive oxygen species (ROS), as observed by EPR spectroscopy. When used as an ROS scavenger, large 1,3-diphenylisobenzofuran is degraded by the best-performing TPA 10 times faster than by DGIST-1, suggesting that the accessibility of molecules (reactants) to pores (reactive centers) strongly influences photocatalytic activity.
Original language | English |
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Pages (from-to) | 21591-21596 |
Number of pages | 6 |
Journal | Angewandte Chemie - International Edition |
Volume | 59 |
Issue number | 48 |
DOIs | |
State | Published - 23 Nov 2020 |
Bibliographical note
Publisher Copyright:© 2020 Wiley-VCH GmbH
Keywords
- hierarchical porosity
- metal–organic aerogels
- photocatalysis
- photooxidation
- reactive oxygen species