Strong Electron-Transfer in Covalently Integrating Cu(I)-Triazine
Frameworks Enabling Benchmark Radionuclide Capture
Abstract
Rational construction of strong electron-transfer materials remains a
challenging task. Herein, we show a fundamental design rule for
construction of strong electron-transfer materials through covalently
integrating electron-donoring Cu(I) clusters and electron-withdrawing
triazine monomers together. As expected, the two resultant
Cu(I)-triazine frameworks (Cu-CTFs) showed strong electron transfer up
to 0.46|e| from each Cu(I) metal center to each
adjacent triazine fragment, and the size of triazine monomer was found
to give tunable ability for electron transfer. Accompanied to the
stronger electron transfer is the observation of more narrow bang gap
and good spatial separation of HOMO and LUMO level. This finally leads
to good spatial separation of photo-generated electron-hole pairs and
function units for boosting photocatalytic reduction of uranium under
ambience and no sacrificial agent with ultrahigh removal efficiency up
to 99.7%, and good charge separation of [I+][I5-] for boosting
I2 immobilization under extremely rigorous conditions with benchmark I2
uptake of 0.32 g/g. The results not only have opened up a structural
design principle to access electron-transfer materials, but also solved
several challenging tasks in the field of radionuclide capture and CTFs.