The capture and separation of fluorinated gases (F-gases) from N2 has the potential to not only reduce greenhouse gas emissions but also provide economic benefits for the semiconductor industry. In this work, two Ni-based metal–organic frameworks (MOFs), Ni-MOF (Ni­(ina)2, ina = isonicotinic acid) and amine-functionalized NH 2 –Ni-MOF (Ni­(3-ain)2, 3-ain = 3-aminoisonicotinic acid), were constructed for capturing F-gases (CF4 and NF3). At ambient conditions, both materials exhibit very high CF4 sorption capacities (2.92 mmol g–1 for Ni-MOF and 2.69 mmol g–1 for NH 2 –Ni-MOF). In addition, NH 2 –Ni-MOF exhibited a record selectivity of 46.3 for the CF4/N2 mixture at 298 K and 100 kPa, surpassing all benchmark adsorbents, including Ni-MOF (34.7). The kinetic adsorption tests demonstrated that Ni-MOF and NH 2 –Ni-MOF performed well for CF4/N2 and NF3/N2 mixtures. According to grand canonical Monte Carlo (GCMC) simulations, CF4 or NF3 interacts with NH 2 –Ni-MOF by multiple van der Waals interactions, resulting in stronger interaction than N2. More importantly, dynamic breakthrough experiments verified the practical separation potential of the two materials for CF4/N2 and NF3/N2 mixtures.

Reducing carbon dioxide (CO 2 ) via photocatalysis to carbon-based materials is a challenging process due to the complexity of the process and the production of several byproducts. Therefore, it is crucial to develop photocatalysts with high yield and selectivity for CO 2 reduction. Herein, we present a strategy for creating high-performance catalysts by immobilizing Ni, Co, and Cu ions in NH 2 -UiO-66 by covalently linking the isatin-Schiff base metal complexes (IS) to the micropores. The as-synthesized NH 2 -UiO-66/IS-complex (66-IS-M, M = Ni, Co, Cu) photocatalysts exhibit special photocatalytic activity for the reduction of CO 2 because of the immobilized metal ions serving as active sites during the reaction. Among them, 66-IS-Ni has a maximum CO generation rate of 1350 μmol g −1 h −1 and a CO selectivity of 87%, both of which are significantly higher than those of previously reported metal−organic framework (MOF)-based photocatalysts. Experimental characterizations and density functional theory (DFT) calculations reveal that the effective charge separation and lowered free energy of CO 2 reduction on 66-IS-Ni promote CO 2 conversion. This study presents a universal strategy for the uniform dispersion of molecular catalysts in amino-functionalized MOF for efficient photocatalytic applications.

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The development of photocorrosion-resistant, recoverable, and stable photocatalysts for high-efficiency visible light photocatalytic production of hydrogen is a very urgent task. Herein, a strategy to fabricate CuO@TiO 2 heterojunction photocatalysts (CuTi-X) by calcining a dual metal−organic framework at different temperatures has been reported. The results reveal that the CuTi-X catalysts have a regular morphology, highly porous structure, and large specific surface area, providing more contact sites for surface mass transfer in photocatalytic reactions. The TiO 2 component is in close contact with the CuO layer uniformly supported on the surface, which facilitates the migration and separation of photogenerated carriers. Optical and electrochemical analyses further confirm that the optimized CuO@TiO 2 (CuTi-450) heterojunction exhibits an extended photogenerated carrier lifetime and a reduced mass transfer resistance. CuTi-450 shows a photocatalytic hydrogen evolution rate under visible light irradiation of 1458.1 μmol g −1 h −1 , which is 36.2 and 5.5 times higher than that of the single TiO 2 (Ti-450) and CuO (Cu-450) components, respectively, and remains stable after four reaction cycles. This work opens an avenue to design stable and efficient oxide heterojunction photocatalysts derived from dual MOFs.

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