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

Abstract

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. Herein, 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 performance of imine‐based COFs was unveiled in‐depth 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.

Fabrication of Biomolecule–Covalent-Organic-Framework Composites as Responsive Platforms for Smart Regulation of Fermentation Application

“…Among these materials, TPB-DMTP exhibited the most apparent pH response, which was probably attributed to the imine moieties in TPB-DMTP, which were readily protonated. 45 According to the literature, 46 the imine-based COF (TPB-DMTP COF) showed positive charges in acidic solutions accompanied by the color change of the material due to the protonation of the imine groups (CN to C NH + ). As the fermentation process was conducted, the solution's pH reduced below 7, and COF carried more positive charges.…”

Metal-free covalent organic frameworks containing precise heteroatoms for electrocatalytic oxygen reduction reaction

“…This similarity arises from the identical chemical environment of N in the imine bond. 52 However, the different electronegativities of O, S, and Se introduce variability in the binding energies of the second peak associated with N. Specically, the Se-N]C peak appears at 399.1 eV in JUC-616, the S-N]C peak at 399.3 eV in JUC-617, and the O-N]C peak at 400.5 eV in JUC-618. [53][54][55] For the high-resolution S 2p spectrum of JUC-616, the binding energies at 165.3 and 164.1 eV were ascribed to C-S-C in the BTT unit.…”

Functionality of Covalent Organic Framework (COF) in Gas Storage Application: First Principal Study

“…The current Occupational Safety and Health Administration (OSHA) Air Quality Guidelines for workplace ambient ozone recommend a limit of 200 μgm −3 (≈ 100 ppb). Working in an environment that exceeds the limit may pose health risks to humans [7].…”

“…Thus, developing new materials to detect and reduce ozone and nitric oxide pollutants is considered of a significant and urgent demand. The dominant approaches for ozone removal are based on traditional activated carbon adsorption, chemical absorption, and catalytic decomposition methods [7]. While ion exchanged zeolites are well known for their efficient catalytic NO conversion [10].…”

“…While ion exchanged zeolites are well known for their efficient catalytic NO conversion [10]. Currently, there is still lacking advanced materials that can be applied for sensing and removal of air pollutants like ozone and nitric oxide [7]. Covalent organic frameworks (COFs) are covalent porous crystalline polymers that allow for the intricate integration of organic building components into an organized structure with atomic precision to construct predesigned skeletons and nanopores [11].…”