Porphyrinoid metal-organic frameworks (MOFs) with dual effective uranium uptake sites were synthesized through combined in-situ and post-synthetic method. The MOF10@5 demonstrates the uptake amount of uranium reaches 1476 mg/g under visible-light irradiation. The PN-MOF10@5 with dual uranyl uptake sites yields the amount of extracting uranyl of 1590 mg/g under visible-light irradiation. The density functional theory (DFT) calculations reveal strong interaction between uranyl and dual uranyl effective active sites. These MOFs demonstrate a powerful synthesis strategy for uranium extraction materials with dual effective active sites.

The separation of CO₂/C₂H₂ mixture by CO₂-selective sorbents is an energy-efficient C₂H₂ purification technique, but is strategically challenging due to their similar molecular size and physicochemical properties. Meanwhile, water is inevitable in CO₂/C₂H₂ mixture and it is usually a significant barrier because of its competitive adsorption with CO₂. To address this challenge, herein, we report the first example of metal–organic framework (MOF) that exhibits water-boosted CO₂ adsorption and CO₂/C₂H₂ separation by anchoring L-arginine (ARG) on the Zr₆ cluster of MOF-808. The CO₂ affinity and capacity in the resulting MOF-808-ARG are markedly facilitated by the presence of water, while the C₂H₂ adsorption is significantly suppressed. Specifically, CO₂ adsorption capacities in adsorption isotherm and breakthrough measurement are increased to 143% and 184%, respectively. In addition, the wet MOF-808-ARG exhibits the record CO₂/C₂H₂ selectivity of 1,180 under zero coverage. Breakthrough experiments reveal that CO₂/C₂H₂ mixture can be completely separated and the result of mass spectrometry indicates that the C₂H₂ purity in the outlet is up to 99.9%. In situ infrared (IR) results and density functional theory (DFT) calculations reveal the water-promoted CO₂ adsorption mechanism that the formation of bicarbonate products in the presence of water is thermodynamically and kinetically more favorable than that without water. Moreover, MOF-808-ARG also possesses excellent water stability and excellent regeneration of CO₂ adsorption. This work provides a new paradigm by transforming the negative effects of water into positive ones for CO₂/C₂H₂ separation.

The simultaneous high-capacity and fast removal of radioactive barium ion (Ba²⁺) from nuclear wastewater is necessary but still faces large challenge. In this study, a novel adsorbent containing sulfonic group, MOF-808-SO₃H, was prepared based on the oxidation of –SH group. Characterizations confirm the successful introduction of –SO₃H, good porosity, and stability of the material. The adsorbent exhibits excellent capture ability for Ba²⁺ due to strong hard acid-base and electrostatic interactions, with the adsorption capacity of 152.0 mg g⁻¹ and fast equilibrium adsorption time, superior to other reported materials. Optimal pH was found to be almost neutral and temperature cannot affect the adsorption largely. Besides, the irreversible adsorption was demonstrated and thereby the secondary pollution may be avoided. Therefore, our work provides an efficient adsorbent for capturing Ba²⁺ irreversibly, and proposes a feasible strategy for constructing adsorbents with simultaneous high adsorption capacity and fast kinetics.