Youssef Belmabkhout

Although iron‐based metal–organic frameworks (MOFs) have been investigated as controlled‐release fertilizers, mixed‐metal (Fe‐M) MOFs remain largely unexplored as platforms for the controlled, simultaneous delivery of multiple micronutrients. This study presents the rational design of biosourced mixed‐metal cluster‐based MOFs, Fe ₂ M‐fumarate (M = Cu, Zn, Mn), and isostructural with MIL‐88A (Fe). The frameworks serve a dual purpose: as degradable micronutrient fertilizers that enable controlled metal release through the slow breakdown of secondary building units and as reservoirs for atmospheric moisture due to their water‐adsorption characteristics. Physicochemical characterization confirmed the successful formation of homogeneous mixed‐metal clusters, yielding spindle‐shaped crystallites with distinct porosity profiles. Notably, the Fe ₂ Cu–MIL‐88A analogue exhibited a unique “breathing” behavior, achieving a remarkable water vapor uptake of ~630 mg g ⁻¹ , significantly outperforming the Zn and Mn analogues. In contrast to the rapid dissolution characteristic of conventional salts, in vitro release assays revealed a biphasic profile, with a gradual initial release of Cu, Zn, or Mn, followed by a more sustained release of Fe, driven by hydrolytic matrix degradation. Kinetic modeling indicated that the Weibull model ( R ² ≤ 0.98) best describes this complex mechanism, which combines erosion and diffusion. The release profiles can be tuned by varying the secondary metal within the trimeric cluster, illustrating the versatility of this approach. These findings position Fe ₂ M–fumarate nanorods as a promising platform for moisture‐responsive, sustained‐release micronutrient delivery in agricultural environments.

The fascinating feature of metal-organic frameworks is that they can respond to external stimuli, unlike other inorganic materials. This feature corresponds to the framework's flexibility, which originates with the long-range crystalline order of the framework accompanied by cooperative structural transformability. We have synthesized a novel metal-organic framework comprised of Cu(I) nodes with pyrazine linkers and benzene-1,3,5-tricarboxylate acting as template anions, named CUCAM-1 [Cu(Py)₂(BTC)]_n. In the presence of polar solvent systems, CUCAM-1 undergoes an irreversible structural transformation to yield a mixed phase that consists of HKUST-1 [Cu₃(BTC)₂(H₂O)₃]_n and another CUCAM-2 [Cu(Py)(BTC)]_n MOFs, whose novel structure is successfully revealed by continuous rotation electron diffraction from the mixture. In this structural transformation, a new ligand exchange occurs where template anions become ligands, confirmed by single crystal X-ray analysis. Further, structural transformation and the mechanism are explained by ab initio molecular dynamics (AIMD) simulations. Interestingly, different halides (F^-, Cl^-, and Br^-) can be accompanied to affect/control the composition of the second phase by favoring the formation of the HKUST-1 phase over CUCAM-2, which was evident by the powder X-ray diffraction studies. Furthermore, the structural transformation induced by I^- resulted in a colorimetric response due to the formation of a new MOF CUCAM-3, paving the way for use as an iodide detector.

Cyanide is highly toxic, with widespread industrial use posing serious environmental risks. Effective materials for detecting and filtering cyanide from water are urgently needed. This study introduces a novel approach utilizing Cu-TCPP (TCPP = o-tetra(4-carboxyphenyl)porphine) metal-organic nanosheets (MONS) embedded in thin-film composite membranes, offering a multifunctional solution for cyanide detection and filtration. Ultrathin Cu-TCPP MONs were synthesized using a surfactant-assisted method featuring highly accessible metal centers that enhance cyanide interaction and detection. The membranes, developed by modifying cellulose acetate (CA) with Cu-TCPP MONs, demonstrated exceptional performance for cyanide removal. The 6% Cu-TCPP/CA membrane exhibited a 2.3-fold increase in pure water permeability and achieved a cyanide removal efficiency of 94.68%, significantly outperforming the pristine 0% Cu-TCPP/CA membrane (Pure Water Permeability (PWP) = 380.83 L m^-2 h^-1 bar^-1; CN^- removal = 5.01%). This is the first report describing the detection and removal of CN^- in water using the membrane technique in literature. In addition to its removal efficiency, the Cu-TCPP MONs showed remarkable detection capabilities, with a calculated limit of detection of 1.76 × 10^-7 M, surpassing World Health Organization (WHO) and United States Environmental Protection Agency (EPA) safety standards for cyanide levels in water. Additionally, Cu-TCPP MONs, a bioimaging agent with excellent cell viability, were deployed to detect CN^- in MiaPaCa-2 cells, detecting concentrations as low as 0.1 ppm.