ZIF-8 synthesized in aqueous solution has a large surface area and high CO₂ adsorption capacity.

As a new class of electrodes, MXenes have shown excellent performance in supercapacitors. At the same time, ionic liquid (IL) electrolytes with wider electrochemical windows are expected to substantially increase the supercapacitor capacitance. The combination of MXenes and ILs is promising for energy storage devices with a high energy density and power density. The studies have indicated that the surface terminations of MXenes and the functional groups of ILs, can both strongly influence the supercapacitor's performance. However, studies at the molecular level are still lacking. In this work, we performed molecular dynamics simulations to investigate the interfacial structures and their influence on the energy storage mechanism. The results show that the two ILs exhibit very different charging rates, though the charge densities are similar after charging equilibrium. The interfacial analysis reveals different electrical double-layer (EDL) structures, in which most cations stay perpendicular to the Ti₃C₂(OH)₂ electrode when some cations shift to a vertical arrangement near the Ti₃C₂O₂ electrode. Such structures have led to the higher capacitance of the Ti₃C₂(OH)₂ electrode, even more than 2 times that of the Ti₃C₂O₂ electrode as the potential difference ranges from 0 to 2 V. It was also found that hydrogen bonds between the –OH groups of HEMIm⁺ cations and terminations of the MXene play an important role in improving the capacitances by aggregating more HEMIm⁺ cations on the surface of the Ti₃C₂(OH)₂ electrode. Our work provides clear mechanistic evidence that both terminations of the MXene electrodes and functional groups of the IL electrolytes affect the interfacial structures and the EDL formation, further leading to the different supercapacitor performance, which will be helpful in designing highly efficient energy-storage devices.

CO₂ is the single most important anthropogenic greenhouse gas, contributing ∼64% to the global radiative forcing. And the rising concentration of CO₂ in the atmosphere will result in global climate change. In this study, 1-alkyl-3-methylimidazolium bromide ionic liquids (ILs) ([C_nMIM]Br, n = 4, 6, 8, 10) were ship in a bottle synthesized in NaY zeolite to get [C_nMIM]Br@NaY samples and applied for CO₂ capture. These samples were then characterized by elemental analysis, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and FT-Raman spectra. The results indicated that [C_nMIM]Br ILs were successfully encapsulated inside NaY and the encapsulated [C_nMIM]Br ILs were much more stable than their bulk analogues. And Raman spectra showed that the relative intensities of some peaks in the [C_nMIM]Br@NaY samples had good relationships with the side chain length of ILs. Then the breakthrough curves were recorded to evaluate the CO₂ adsorption capacity of these samples, and indicated that the highest adsorption capacity could reach up to 20.08 mL CO₂ per g [C₄MIM]Br@NaY. And the cyclic CO₂ adsorption results also illustrated that the [C_nMIM]Br@NaY samples were stable and effective with prolonged use. So these samples could be potential materials for CO₂ capture.

Deep desulfurization of fossil fuels has become urgently required because of the serious pollution by the large-scale use of fossil fuels. In this study, [PrSO₃HMIm]HSO₄@MIL-100(Fe) was synthesized by wet-impregnation of the ionic liquid (IL) of [PrSO₃HMIm]HSO₄ on MIL-100(Fe). The construction of [PrSO₃HMIm]HSO₄@MIL-100(Fe) was then confirmed by X-ray powder diffraction, N₂ adsorption–desorption experiments, infrared spectroscopy and elemental analysis, and then applied in the oxidative desulfurization of model fuels. In comparison with the corresponding IL, [PrSO₃HMIm]HSO₄@MIL-100(Fe) showed an enhanced performance in the desulfurization rate of model fuels due to the increase of the mass transfer rate. Under the optimized conditions (oxidant to sulphur ratio = 25, oil to acetonitrile ratio = 1, and temperature = 60 °C), a sulphur removal rate of 99.3% was observed (initial sulphur concentration = 50 ppm). The sulphur removal of three sulphur compounds by catalytic oxidation and extraction followed the order of dibenzothiophene (DBT) > thiophene (T) > benzothiophene (BT).

The photodegradation efficiency of imidazolium ILs reach 95% with DCQ-TiO₂/SiO₂ as the photocatalyst under simulated solar light.