In this work, zeolitic imidazolate frameworks (ZIF-8) and carboxylated carbon nanotubes (CNTs) were compounded to prepare a kebab-like one-dimensional linear composite, [email protected] The mixed-matrix membrane (MMM) for separating carbon dioxide is prepared by embedding it into the polymer matrix Pebax-1657. The results indicated the successful synthesis of the [email protected] composite. The combination of ZIF-8 and carboxylated CNTs avoided the aggregation of ZIF-8 in the polymer, increased the free volume of the MMM, and enhanced the CO2 adsorption performance and CO2/N2 separation performance. In addition, the interaction between CNTs and ZIF-8 provided a fast transport channel for CO2 molecules and improved the mechanical properties of the MMM. The 5 wt % [email protected] MMM showed the best separation performance with a CO2 permeability of 225.5 Barrer and a CO2/N2 selectivity of 48.9, which exceeded the Robeson upper limit in 2008. The combination of high permeability and selectivity made Pebax/[email protected] MMMs promising for industrial CO2 separation applications.
8 March 2022 in Journal of Colloid and Interface Science
Metal nanozymes hold promise for chemical and biological applications, and their implementation relies on high catalytic efficiency and stability. Using the metal–organic framework as an ideal carrier for well-dispersed ultra-small metal nanoparticles (NPs) is beneficial for improving the catalytic efficiency of nanozymes. In this study, a zirconium-based metal organic framework (UiO-66) with good chemical stability and high porosity was synthesized and used to construct Pt/UiO-66 nanocomposites. The percentage of Pt in UiO-66 can be tuned easily by adjusting the feeding amount of PtCl42–. Because of the confinement effect of mesopores, the Pt particles with an average diameter of 3.8 nm are formed and dispersed throughout the pores of the UiO-66 particle. The Pt/UiO-66 composites show efficient oxidase- and peroxidase-like activity. Both the oxidase- and peroxidase-like activities are dependent on the Pt percentage. Pt/UiO-66-6% exhibits enhanced peroxidase-like activity, ∼3.9 times higher than that of commercial Pt/C with 10 wt % Pt. We propose that the construction of Pt/UiO-66 increased the utilization efficiency and stability of Pt NPs and provided more active sites for catalytic reactions. Using the peroxidase-like activity of Pt/UiO-66, a colorimetric method that can be used for actual blood glucose detection was developed for the specific detection of glucose with a limit of detection of 0.033 mM.