Instead of using organic solvents, a deep eutectic solvent (DES) composed of tetrabutylammonium bromide and imidazole (Bu4NBr/Im) was employed as a solvent for the first time to synthesize covalent organic frameworks (COFs). Due to the low vapor pressure of the Bu4NBr/Im‐based DES, a new carboxyl‐functionalized COF (TpPa‐COOH) was synthesized under environmental pressure. The as‐synthesized TpPa‐COOH has open channels, and the DES can be removed completely from the pores. The dye adsorption performance of TpPa‐COOH was examined for three organic dyes with similar molecular sizes: one anionic dye (eosin B, EB) and two cationic dyes (methylene blue, MB and safranine T, ST). TpPa‐COOH showed an excellent selective adsorption effect on MB and ST. The electronegative keto form in TpPa‐COOH might help to form electrostatic and π–π interactions between the π‐stacking frameworks of TpPa‐COOH and the positive plane MB and ST molecules. The adsorption isotherms of MB and ST on TpPa‐COOH were further investigated in detail, and the equilibrium adsorption was well modeled by using a Langmuir isotherm model. Together with hydrogen bonding, TpPa‐COOH showed higher adsorption capacity for ST than for MB (1135 vs. 410 mg g−1). These results could provide a guidance for the green synthesis of adsorbents in removing organic dyes from wastewater.

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This paper described a facile preparation of a fluorinated covalent triazine framework (2F-CTF) via an AlCl 3 -catalyzed Friedel−Crafts reaction and the employment of 2F-CTF as the precursor to prepare defluorinated porous carbon nanomaterials (df-CTF-KT) with the aid of KOH. The C−F bonds can generate reactive fluorinated species during carbonization and etch the precursor's backbone to afford improved porosity. Especially, df-CTF-K700 exhibited a higher surface area and microporosity when compared with the precursor 2F-CTF (1914 vs 1122 m 2 g −1 and 0.633 vs 0.282 cm 3 g −1 ) and thus afforded increased CO 2 uptake under 1 bar (391 vs 215 mg g −1 at 273 K and 218 vs 101 mg g −1 at 298 K). A non-fluorinated CTF and its carbonization product were synthesized to understand the important role of fluorine in CTFs and porous carbon nanomaterials. Both 2F-CTF and df-CTF-K700 showed higher CO 2 uptake capacity than the non-fluorinated CTF and derived porous carbons, respectively. Importantly, the CO 2 uptake capacity of df-CTF-K700 is much better than most of the reported porous carbons and other porous adsorbents, and the Q st value at zero coverage is 27.3 kJ mol −1 , affording the facile desorption process.

Deep eutectic solvents (DESs)-containing three-dimensional (3D) porous organic polymers (termed TAM-BPA-ChCl/Ur, TAM-BPA-ChCl/Gly, and TAM-BPA-Bu 4 NBr/Im) were obtained via one-pot synthesis by using DESs as green reaction solvents for the first time. The DESs were confined into 3D extended structures during the synthetic process, as revealed by a series of techniques. The DESs-loaded polymeric materials were used to catalyze the Knoevenagel condensation of aldehydes and malononitrile and produced excellent yields at room temperature. As a typical example, the TAM-BPA-ChCl/Ur sample as a heterogeneous catalyst can be recovered easily and shows stable catalytic activity. This research presents a feasible method to prepare functional complex materials involving DESs and porous polymers.