Cucurbit[6]uril@MIL-101-Cl: loading polar porous cages in mesoporous stable host for enhanced SO₂ adsorption at low pressures

Abstract

The robust cucurbituril-MOF composite CB6@MIL-101-Cl was synthesized by a wet impregnation method and a concomitant OH-to-Cl ligand exchange {CB6 = cucurbit[6]uril, 31wt% content in the composite, MIL-101-Cl = [Cr3(O)Cl(H2O)2(BDC)3], BDC...

Cucurbituril-Based Supramolecular Assemblies: Prospective on Drug Delivery, Sensing, Separation, and Catalytic Applications

“…This composite shows a synergistic effect toward a high SO 2 uptake of 438 cm 3 g –1 (19.5 mmol g –1 ) at 1 bar and 293 K by combining the strong SO 2 affinity of the CB6 macrocycle and the high SO 2 uptake capacity of MIL-101 . The captured amount of SO 2 is 2.2 mmol g –1 for CB6@MIL-101-Cl at 0.01 bar and 293 K (2.0 mmol g –1 at 298 K), which is 3 times higher than that of the parent MIL-101 (0.7 mmol g –1 ) under the same conditions . The synthesized composite enhances the performance in the removal of SO 2 gas under low pressure and the stability even under humid SO 2 conditions.…”

“…The synthesized composite enhances the performance in the removal of SO 2 gas under low pressure and the stability even under humid SO 2 conditions. Comparative experiments demonstrated losses of crystallinity and porosity after dry SO 2 adsorption for MIL-101, and CB6@MIL-101-Cl exhibits nearly complete retention of crystallinity and porosity under exposure to both dry and wet SO 2 . Thus, CB6@MIL-101-Cl can be an attractive adsorbent for SO 2 capture because of its excellent recycling stability, high capacity, and strong affinity for SO 2 at low pressure.…”

Capture and detection of SO2 using a chemically stable Mg(ii)–MOF

“…Remarkably, the SO 2 uptake in Mg 2 (dobpdc) is higher than that shown by other representative MOFs at 298 K and up to 1 bar, see Table S1† ( e.g. , MFM-170, 20 MIL-101(Cr)–4F(1%), 21 and the cucurbituril–MOF composite CB6@MIL-101-Cl, 22 with reported SO 2 uptakes of 17.5 mmol g −1 , 18.4 mmol g −1 and 17.0 mmol g −1 , respectively). On the other hand, the SO 2 adsorption of Mg 2 (dobpdc) at 0.1 bar is lower (7.4 mmol g −1 ) than that of benchmark materials such as HKUST-1, 18 SIFSIX-1-Cu, 14 i MFM-300(Sc), 19 c and NH 2 -MIL-125(Ti) 48 with a reported SO 2 capture of 10.1, 8.74, 8 and 7.9 mmol g −1 , respectively.…”

“…16 The family of hybrid porous materials, namely metal–organic frameworks (MOFs) or porous coordination polymers (PCPs) has been envisaged for SO 2 capture. A few MOF candidates including MFM-300(M) (M = Al 3+ , In 3+ and Sc 3+ ), 19 MFM-170, 20 MIL-101(Cr)–4F(1%) 21 and CB6@MIL-101-Cl 22 were demonstrated to be stable towards SO 2 exposure and associated with relatively large SO 2 uptake at 298 K and 1 bar of 7.1, 8.28, 9.4, 17.5, 18.4, and 17.0 mmol g −1 , respectively. In addition to the capture of SO 2 in large quantities, the detection of SO 2 is also desirable in order to identify potential polluted environments with this toxic gas.…”

Low-Temperature and Additive-Free Synthesis of Spherical MIL-101(Cr) with Enhanced Dye Adsorption Performance

“…The terminal connected water molecules of MIL-101(Cr) can be removed under high temperature or vacuum conditions, which creates potential Lewis acid sites [20]. Hence, MIL-101(Cr) demonstrates quite good water stability, which makes it suitable for wide applications, especially in the presence of moisture/water conditions, such as catalysis [21,22], adsorption [23,24], separation [25,26], drug delivery [27,28], gas storage [29,30], water pollution treatment [31], and mixed matrix membranes [32,33], among others.…”