Feasible defect and hydrophobic modification of MIL-100(Cr) for efficient toluene removal from air

We developed a feasible strategy to obtain the defective MIL-100(Cr) (De-M) via doping 3,5-pyridinedicarboxylate and subsequently loaded polydivinylbenzene (PDVB) by thermal deposition to obtain a hydrophobic MOFs composite (De-M@PDVB). De-M10 (10 % defective ligand/total ligands) exhibited excellent performance for the capture of toluene due to uniform particle size, high specific surface area and pore volume. Subsequent thermal deposition with PDVB further increased the hydrophobicity, as-obtained De-M10@PDVB in the dynamic adsorption experiment showed about 2 and 1.5 time adsorption capacity as that of primary MIL-100(Cr) and De-M10 under 50 % RH at 298 K. In addition, the toluene uptake of De-M10@PDVB (0.95, 298 K) in static adsorption experiments was 1320 mg/g, much higher than many reported MOFs. Furthermore, De-M10@PDVB could be regenerated at 378 K, demonstrating its excellent regenerability at low temperature. The adsorption mechanism of toluene on De-M10@PDVB could be attribute to the π-π stacking interaction between the benzene ring of toluene with H3BTC and adsorption sites offered by the incorporation of H2DL in the framework of MIL-100(Cr) according to XPS analysis. Our finding provided a novel strategy by constructing defective MIL-100(Cr) and introducing PDVB to enhance efficient adsorption for toluene capture even in humid air.