Vicinal dual hydroxyl functional mesoporous poly(ionic liquid)s with large surface area and high ionic liquid (IL) content were synthesized through the copolymerization of epoxy-containing IL monomers and divinylbenzene, followed by ring opening in water. They acted as recyclable heterogeneous organocatalysts in the cycloaddition of a series of epoxides with CO 2 under mild conditions (down to ambient conditions). The catalyst can be lightly recovered and reused with stable activity. The remarkable performance was attributable to the abundant mesoporosity and the synergistic effect of vicinal dual hydroxyls as hydrogen-bonding donors and halogen anions as nucleophiles. Density functional theory calculation, comprising the structural optimization, the energetic profile, and the charge and energy decomposition analysis by the combination of the extended transition state energy decomposition scheme with the natural orbitals for chemical valence approach, was performed to afford insight, indicating that the vicinal dual hydroxyls accelerated the reaction by providing a strong hydrogen-bonding effect and enhancing the leaving ability of the halogen anions.

Hybrid layered double hydroxides (LDHs)/graphene oxide (GO) nanocomposites are novel two-dimensional (2-D) materials applied in extensive fields, which take advantages of the synergistic effect of LDH and GO at the composite interface. However, the interfacial interaction mechanism determining the LDH/GO nanocomposite properties still remains to be explored. Herein, we used density functional theory to comprehensively illustrate interfacial interactions, as well as structural and electronic properties of Mg/Al LDH/GO nanocomposites. Our results, for the first time, reveal that there exists unique water-generated chemical interaction during the LDH/GO combining process. The generated interfacial water molecules play a key role in maintaining the nanocomposites by forming complicated and diverse interfacial hydrogen bond structures. Moreover, the transfer of the hydrogen atom from LDH to the epoxy group resulting in hydroxyl was also observed. The results provide hints for interpreting previous experimental observations. There is interfacial charge transfer from LDH to GO and water molecules. The electrical properties of the LDH component in the composite can be modulated by properly varying the epoxy/ hydroxyl ratio on GO. The current results might prove to be instrumental in the design of 2-D heterostructural LDH/GO composites.