The synthesis of hierarchically mesoporous polymers with multiple functionalities is challenging. Herein we reported a template-free strategy for synthesis of phenolic azo-polymers with hierarchical porous structures based on diazo-coupling reaction in aqueous solution under mild conditions. The resultant polymers have surface areas up to 593 m² g⁻¹ with the mesopore ratio of >80 %, and a good ability to complex with metal ions, such as Cu²⁺, Zn²⁺,Ni²⁺, achieving a metal loading up to 26.24 wt %. Moreover, the polymers complexed with Zn showed excellent performance for catalyzing the reaction of CO₂ with epoxide, affording a TOF of 2570 h⁻¹ in the presence of tetrabutyl ammonium bromide (7.2 mol %). The polymer complexed with Cu could catalyze the oxidation of alcohol with high efficiency.

The formylation of aryl halides with CO₂ to generate aryl aldehydes is challenging. Herein, we report a novel synthesis of aryl aldehydes by formylation of aryl bromides with CO₂ and a waste silane, poly(methylhydrosiloxane) (PMHS). It has been discovered that a simple combination of 1,3-bis(diphenyphosphino)propane (DPPP)-chelated Pd catalyst, Pd(DPPP)Cl₂, with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is able to effectively catalyze the reaction, leading to aryl aldehydes in moderate to excellent yields, and without any by-products in most cases. Moreover, this route could be extended to the formylation of aryl iodides with high efficiency. This approach is simple, less costly, and environmentally friendly, and also widens the applications of CO₂ to form value-added chemicals by the construction of new C−C bonds.

The synthesis of hierarchically mesoporous polymers with multiple functionalities is challenging. Herein we reported a template-free strategy for synthesis of phenolic azo-polymers with hierarchical porous structures based on diazo-coupling reaction in aqueous solution under mild conditions. The resultant polymers have surface areas up to 593 m² g⁻¹ with the mesopore ratio of >80 %, and a good ability to complex with metal ions, such as Cu²⁺, Zn²⁺,Ni²⁺, achieving a metal loading up to 26.24 wt %. Moreover, the polymers complexed with Zn showed excellent performance for catalyzing the reaction of CO₂ with epoxide, affording a TOF of 2570 h⁻¹ in the presence of tetrabutyl ammonium bromide (7.2 mol %). The polymer complexed with Cu could catalyze the oxidation of alcohol with high efficiency.

The chemical fixation of CO₂ under mild reaction conditions is of significance from a sustainable chemistry viewpoint. Herein a CO₂-reactive protic ionic liquid (PIL), [HDBU⁺][TFE⁻], was designed by neutralization of the superbase 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with a weak proton donor trifluoroethanol (TFE). As a bifunctional catalyst for simultaneously activating CO₂ and the substrate, this PIL displayed excellent performance in catalyzing the reactions of CO₂ with 2-aminobenzonitriles at atmospheric pressure and room temperature, thus producing a series of quinazoline-2,4(1H,3H)-diones in excellent yields.

The chemical fixation of CO₂ under mild reaction conditions is of significance from a sustainable chemistry viewpoint. Herein a CO₂-reactive protic ionic liquid (PIL), [HDBU⁺][TFE⁻], was designed by neutralization of the superbase 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with a weak proton donor trifluoroethanol (TFE). As a bifunctional catalyst for simultaneously activating CO₂ and the substrate, this PIL displayed excellent performance in catalyzing the reactions of CO₂ with 2-aminobenzonitriles at atmospheric pressure and room temperature, thus producing a series of quinazoline-2,4(1H,3H)-diones in excellent yields.

A high-yielding exfoliation of graphene at high concentrations in aqueous solutions is critical for both fundamental study and future applications. Herein, we demonstrate the formation of stable aqueous dispersions of pristine graphene by using the surfactant sodium taurodeoxycholate under tip sonication at concentrations of up to 7.1 mg mL⁻¹. TEM showed that about 8 % of the graphene flakes consisted of monolayers and 82 % of the flakes consisted of less than five layers. The dispersions were stable regardless of freezing (−20 °C) or heat treatment (80 °C) for 24 h. The concentration could be significantly improved to about 12 mg mL⁻¹ by vacuum-evaporation of the dispersions at ambient temperature. The as-prepared graphene dispersions were readily cast into conductive films and were also processed to prepare Pt/graphene nanocomposites that were used as highly active electrocatalysts for the oxygen-reduction reaction.

Covalent immobilization of glycidyl-group-containing ionic liquids (ILs) on organic and inorganic supports with functional surfaces was achieved, based on the fact that the glycidyl group can actively react with almost all nucleophilic, electrophilic, neutral, and free-radical species. By using polymer spheres with amino- and carboxyl-group-functionalized surfaces as organic supports and silicas (including SBA15 and silica gel) with amino groups attached as inorganic supports, the ionic liquid 1-glycidyl-butylimidazolium chloride was successfully grafted onto these polymer and silica supports, respectively, through reactions between the glycidyl group in the IL and the polar groups on the support surfaces. The resultant samples were examined by transmission electron microscopy, solid-state ¹³C NMR spectroscopy, IR spectroscopy, and ion chromatography. The activities of these resultant polymer- and silica- based catalysts were investigated for CO₂ cycloaddition reactions with epoxides. It was demonstrated that these catalysts could effectively catalyze CO₂ cycloaddition. In particular, the polymer supports generated synergistic effects with the IL in the coupling reaction of CO₂ with propylene oxide, and the turnover frequency could reach about 1700 h⁻¹ when the IL attached to the NH₂-functionalized polymer was used as the catalyst.

Carbon-nanotube (CNT) composites have attracted a lot of attention because of their potential applications in many fields. Here, recent advances in the synthesis of CNT composites using supercritical fluids (SCFs) are highlighted. SCFs exhibit unique features for the synthesis of composites because of their unusual properties, such as low viscosity, high diffusivity, near-zero surface tension, and tunability. Preliminary studies show that SCFs show unusual advantages for the synthesis of CNT composites. The morphologies and structures of the resultant CNT composites can be tuned by changing the solvent properties. The SCF methods not only provide a green route for the synthesis of composites, but also result in nanostructures that have not yet been produced by conventional methods. Moreover, the potential applications of the resultant CNT composites are also discussed.