Rational Fabrication of Crystalline Smart Materials for Rapid Detection and Efficient Removal of Ozone.

Traditional ozone sensing and removal materials still suffer from high energy consumption and low efficiency. Thus, seeking new ozone-responsive materials with high efficiency and broad working conditions is of great significance. In this contribution, we first developed covalent organic frameworks (COFs) for smart sensing and efficient removal of ozone. Notably, imine-based COFs possess dramatically fast optical responses (<1 s) to ozone as low as 0.1 ppm under broad working conditions (e.g., in the presence or absence of moisture, room temperature). Moreover, we found that imine-based COFs can also be applied as excellent ozone removers that can efficiently reduce the ozone concentration below the recommended safety limit (<0.1 ppm) for humans. The mechanism for the outstanding performance of imine-based COFs was in-depth unveiled by various characterization techniques and analyses. This study not only provides a new type of advanced materials for ozone sensing and removal but also broadens the application scope of COFs.