Enhanced Adsorption of Aromatic Volatile Organic Compounds on a Perchloro Covalent Triazine Framework through Multiple Intermolecular Interactions

Abstract

AbstractVolatile organic compounds (VOCs) may have short‐ and long‐term adverse health effects. Especially, aromatic VOCs including benzene, toluene, ethylbenzene, and xylene (BTEX) are important indoor air pollutants. Developing highly efficient porous adsorbents with broad applicability remains a major challenge. In this study, a perchlorinated covalent‐triazine framework (ClCTF‐1‐400) is prepared for adsorbing BTEX. ClCTF‐1‐400 is confirmed as a partially oxidized/chlorinated microporous covalent triazine framework through a variety of characterization. It is found that ClCTF‐1‐400 is reversible VOCs absorbent with very high absorption capacities, which can adsorb benzene (693 mg g−1), toluene (621 mg g−1), ethylbenzene (603 mg g−1), o‐xylene (500 mg g−1), m‐xylene (538 mg g−1), and p‐xylene (592 mg g−1) at 25 °C and their saturated vapor pressure (≈ 1 kPa). ClCTF‐1‐400 is of higher adsorption capacities for all selected VOCs than activated carbon and other reported adsorbents. The adsorption mechanism is also inferred through theoretical calculation and in‐site Fourier Transform Infrared (FTIR) spectroscopy. The observed excellent BTEX adsorption performance is attributed to the multiple weak interactions between the ClCTF‐1‐400 frameworks and aromatic molecules through multiple weak interactions (CH…π and CCl…π). The breakthrough experiment demonstrates ClCTF‐1‐400 has the potential for real VOCs pollutant removal in air.