Linshuai Liu,Nannan Wang,Chunlin He,Yuezhou Wei,Jingjing Wang,Xinpeng Wang
Considering the unexpected nuclear power waste emission and potential nuclear leakage, the exploration of robust materials for the effective capture and storage of radioactive iodine is of great importance but still remains a challenge. In this work, we report the rational synthesis of functionalized NH 2 -UiO-66-on-ZIF-67 architecture to enhance the static adsorption and retention of volatile iodine. Such MOF-on-MOF heterostructures was fabricated through seeding ZIF-67 core on the surface of NH 2 -UiO-66 satellite via a facile polyvinylpyrrolidone (PVP) regulated internal extended growth strategies. NH 2 -UiO-66-on-ZIF-67 exhibited unique core-satellite structure, which significantly promotes the binding interactions with iodine through synergizing of the N-rich imidazole moieties and surface functionalized amino groups within the porosity channels. As a result, the as fabricated NH 2 -UiO-66-on-ZIF-67 achieves enhanced mass diffusion and high capture capacity of 3600 mg/g for iodine vapor under static sorption conditions. Moreover, water vapor in humid conditions (relative humidity of 18 %) has almost no effect on the static iodine adsorption performance of the material. This study sheds light on a reliable MOF-on-MOF hybrid strategy for effective radioiodine treatment to ensure the safety nuclear waste management.
Metal–organic frameworks (MOFs), known for their exceptional gas permeability and abundant active sites, are a class of porous coordination polymers that can serve as ideal candidates for constructing advanced gas sensors. However, the limitations of low electrical conductivity and inadequate stability under extreme conditions hinder their advancements in gas-sensing applications. Moreover, a single MOF structure occasionally demonstrates insufficient selectivity toward specific gases, failing to meet stringent sensing requirements. To overcome these challenges, this study innovatively constructs an MOF-on-MOF architecture by etching Ti-MOF into a hollow cage-like structure with l-glutamic acid and connecting it with Ni2+ ions to form Ni-MOF via peptide bonds. The approach not only enhances the specific surface area and pore structure of the material but also facilitates carrier transport rates at the interface by effectively linking the two MOFs. The resultant MOF-on-MOF structure exhibits remarkable selectivity and sensitivity in detecting triethylamine gas at a low operating temperature of 140 °C, along with exceptional reproducibility and long-term stability. This work demonstrates a novel amino acid-assisted feasible and simple method to construct MOF-on-MOF material, showcasing immense potential in high-performance gas detection applications.
Converting CO 2 into high-value-added products via “artificial photosynthesis” under mild conditions is a promising yet challenging strategy for developing efficient photocatalysts. This study reports a simple two-step solvothermal approach to fabricate the dual-metal–organic framework (MOF) nanocomposite NH 2 -UiO-66@PCN-224 (NU-66@PCN-224) with tightly integrated interfaces, which achieves efficient CO 2 to CO photocatalytic reduction under light irradiation. The epitaxially grown PCN-224, composed of Zr 6 clusters and tetrakis (4-carboxyphenyl) porphyrin (TCPP), serves as a shell layer and a visible light-absorbing antenna, thereby broadening the light absorption range of the composite material. Moreover, the tightly integrated interfaces of NU-66@PCN-224 enhance the mobility of photogenerated charge carriers, consequently enhancing its capability for CO 2 catalytic reduction. As a result, the combination of NU-66 and PCN-224 retains their individual advantages while achieving a synergistic enhancement of both adsorption and catalysis, further improving the photocatalytic performance. The as-prepared NU-66@PCN-224 catalyst exhibits outstanding photocatalytic performance, yielding 74.6 μmol g −1 h −1 of CO under irradiation without sacrificial agents or photosensitizers. This work demonstrates a straightforward and effective method for designing MOF-on-MOF photocatalysts with enhanced photoactivity.
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