RESUMEN
The processability and sustainability of proton conductors are two important indicators of their application. Here, MIL-91(Al) with an intrinsic proton conduction framework originating from protonated phosphonate groups was cross-linked with poly(vinyl alcohol) (PVA) to obtain MIL-91(Al) aerogel through freeze-drying. This simple and inexpensive strategy not only facilitated the processing of MIL-91(Al) powder but also resulted in a molded MIL-91(Al) aerogel having a high proton conductivity of 1.02 × 10-2 S cm-1 at 70 °C and 100% relative humidity. Furthermore, MIL-91(Al) aerogel was recyclable and reusable, in line with the principles of environmental protection and sustainability. To the best of our knowledge, this is the first example of using a metal-organic framework aerogel as a proton conductor, which may develop a new model system in this field.
RESUMEN
The development of heterogeneous catalysts with abundant active sites is pivotal for enhancing the efficiency of photothermal CO2 conversion. Herein, we report the construction of Co2N0.67@ZIF-67 through the in situ pyrolysis of ZIF-67 under low-temperature pyrolysis conditions. During the pyrolysis process, the crystal structure of ZIF-67 is predominantly preserved concurrently with the formation of Co2N0.67 nanoparticles (NPs) within the ZIF-67 pores. The optimal catalyst Co2N0.67@ZIF-67(450,2) not only possesses high photothermal efficiency but also can efficiently activate CO2. Benefiting from these characteristics, Co2N0.67@ZIF-67(450,2) exhibited significant catalytic activity in the photocatalytic cycloaddition of CO2 and epichlorohydrin. The yield of (chloromethyl)ethylene carbonate reached 95%, which is more than 4 times higher than that of ZIF-67 under visible light irradiation (300 W·m2 Xe lamp, 3 h). This study could offer an alternative approach to enhance the photocatalytic activity of MOFs through low-temperature pyrolysis.