The sustainable advancement of nuclear energy urgently requires the effective management of radioactive iodine, a hazardous byproduct with significant environmental and safety concerns. Traditional capture-and-store strategies fall short by treating iodine as waste, overlooking its potential for resource utilization. Here, we report a rationally designed bifunctional metal-organic framework (MOF) that synergistically combines high-capacity iodine capture with in-situ catalytic conversion into value-added chemicals. By selecting nitrogen/oxygen-rich ligands (4,4'-azopyridine and oxalic acid) and catalytically active cobalt nodes, we serendipitously obtained a pair of structural isomers: a nonporous compound 1 and a porous compound 2. This unique discovery provides an ideal platform to elucidate the critical role of the porosity. As anticipated, porous 2 exhibited substantially superior iodine adsorption in both vapor and solution phases compared to 1. More importantly, the open channels in 2 serve as an efficient nanoreactor, where absorbed iodine is catalytically converted by O2 at Co sites into iodinated aromatic compounds. Furthermore, 2 showed excellent recyclability, maintaining its structural integrity and catalytic performance over four consecutive cycles. This work not only presents a high-performance material for integrated iodine capture and conversion but also, through a direct isomeric comparison, definitively demonstrates that open porosity is a prerequisite for the efficient iodine enrichment and subsequent catalytic transformation. These findings thus establish a novel design paradigm and compelling experimental evidence for advancing resource-oriented nuclear waste management.

The escalating contamination of soils by tetrabromobisphenol A (TBBPA) necessitates remediation strategies that are both highly efficient and cost-effective. This study evaluates and compares iron nanoparticles greensynthesized using Cinnamomum camphora leaf extract (G-Fe NPs) with chemically synthesized analogues (C-Fe NPs, from NaBH4 reduction) as activators of persulfate (PS) for TBBPA degradation. Theoretical calculations indicate that PS adsorbs more strongly on G-Fe NPs (-1.646 eV) than on C-Fe NPs (-0.487 eV). Experimentally, the G-Fe NPs/PS system demonstrated superior performance, achieving 81.07 +/- 4.01 % TBBPA removal with a rate constant (k) of 0.134 h-1 , compared to 77.32 +/- 4.69 % and a k of 0.128 h-1 for the C-Fe NPs/PS system. The G-Fe NPs/PS system also showed strong adaptability to variations in PS concentration, temperature, catalyst dosage, and pH. Quenching experiments and electron paramagnetic resonance (EPR) analysis revealed that while the C-Fe NPs/PS system primarily drives rapid debromination via SO4 center dot-, center dot OH, and O2 center dot- radicals, the G-Fe NPs/PS system couples these radical pathways with a non-radical 1O2 mechanism to achieve deeper mineralization. Density functional theory (DFT) calculations confirmed the thermodynamic feasibility of the proposed degradation pathways in both systems. Critically, toxicological and physicochemical assessments indicated that the transformation products from the G-Fe NPs/PS system possess significantly lower acute and chronic toxicity, presenting minimal risk to soil ecosystems. Therefore, owing to their favorable structural properties, greensynthesized Fe NPs provide a safe, efficient, and eco-friendly approach for remediating TBBPA-contaminated soils.

Two-dimensional polyoxometalate-based metal-organic frameworks (2D POMOFs) hold great promise for catalysis, yet their directed synthesis and facile exfoliation remain challenging. Herein, we report the rational assembly of an exfoliable 2D POMOF, H5[(Co(H2O)2)2(C18H12N6)4(P2W15Ta3O62)]·18H2O (1), directed by the nonuniform charge distribution within the POM. The unique layered structure enables a multi-step morphological control strategy: hydrothermal synthesis gives access to high-quality single crystals, while a scalable bulk synthesis allows the rapid production of nanobelts, which can subsequently be exfoliated into ultrathin bilayer nanosheets via a liquid-nitrogen treatment, or even monolayer nanosheets via solvent-assisted sonication. The bilayer nanosheets exhibit high catalytic activity and selectivity for alkyne transfer semi-hydrogenation, outperforming the corresponding bulk and nanocrystalline counterparts and rivaling noble-metal-based catalysts. This work establishes charge-asymmetric POM-directed synthesis as a viable strategy for creating defined 2D materials.

An ultrafast fluorescent sensor based on polymer dots (PDs) probe was developed for the portable on-site determination of copper (Cu²⁺) contamination in aquatic products. Due to the secondary internal filtering effect (IFE) induced by coordination of Cu²⁺ with polyethyleneimine (PEI) moieties on PDs surface, the probe enabled ultrafast (within 5 s) and highly sensitive (limit of detection of 52 nM) detection of Cu²⁺. Furthermore, an integrated sensing array composed of PDs/poly(vinyl alcohol) (PVA) film was developed, allowing high-throughput and simultaneous analysis of multiple aquatic product samples within 1 min. By combining quick-response (QR) code technology with smartphone-assisted data processing, a multidimensional dataset was established, including Cu²⁺ concentration, testing location, and temporal information. The PDs/PVA film-based monitoring platform offers a comprehensive approach for tracking Cu²⁺ contamination in aquatic products and shows great potential for applications in food safety surveillance and quality management.

For oxide-supported metal catalysts, metal-support interaction (MSI) facilitates metal dispersion at the expense of the metallic character, resulting in a trade-off between active site utilization and intrinsic activity. Here, we used a thermal aging strategy to modulate the MSI in Cu/CeO2 catalysts, facilitating the formation of metallic Cu sites upon H2 reduction while maintaining metal dispersion. Systematic experiments confirmed that thermal aging at 800°C lowered the reduction temperature and increased the reduction degree of Cu sites. Microscopy evidenced few-atom-layered Cu nanoclusters before and after H2 reduction, whereas in situ spectroscopy revealed metallic Cu nanoparticles under H2 atmosphere. This discrepancy indicated a reversible structural evolution from aggregation to redispersion in thermally aged Cu/CeO2. The catalytic activity for acetylene semihydrogenation was unlocked on metallic Cu sites, compared to nearly inactive Cu sites in conventional Cu/CeO2 counterparts. Our work developed an effective strategy for rational modulation of MSI, offering the feasibility to tailor-make active sites for specific reactions.

Core-shell heterojunction photocatalysts have the effective charge transfer between two different phases to improve the photocatalytic activity. Due to sheet-like structure, MXene was considered as an important three dimensional (3D) shell candidate to enlarge the absorption region of visible light and to prevent the aggregation. In this work, the core-shell SiO2@Bi4Si3O12-Bi4Ti3O12/MXene microspheres were successfully fabricated by a two-step reaction using solvothermal and hydrothermal methods. The reaction factors, such as MXene content, reaction temperature, and time, were investigated on the morphology, structures, and photocatalytic performance of SiO2@Bi4Si3O12-MXene samples. In the similar conditions, the MXene content exhibits the more obvious influence on the structural composition and morphology of the core-shell microspheres. The SiO2@Bi4Si3O12-MXene-6 mg microspheres synthesized under the MXene usage of 6 mg, hydrothermal temperature of 120 °C, and reaction time of 24 h exhibited the higher photocatalytic performance. The photocatalytic degradation efficiency for Rhodamine B (RhB) was highest at 98.81% within 1 h illumination in visible light. Finally, the formation mechanism and the possible photocatalytic mechanism of core-shell SiO2@Bi4Si3O12-Bi4Ti3O12/MXene microspheres were elaborated and suggested. It provides a novel design strategy and efficient fabrication method of bismuth-based photocatalysts.

A series of fluorinated chalcone oxime esters (F-OXEs) were designed and synthesized as efficient Type I photoinitiators for free radical photopolymerization under light-emitting diode (LED) irradiation. The introduction of fluorinated substituents into the oxime ester moiety, combined with modulation of the conjugated chalcone framework, enables effective tuning of the molecular electronic structure and photochemical reactivity. The F-OXEs exhibit broad absorption spanning near-UV to visible region, while the incorporation of a triphenylamine unit leads to a pronounced red shift and enhances light-harvesting capability. Photolysis experiments, electron paramagnetic resonance (EPR) studies and theoretical calculations reveal that the presence of fluorinated groups lowers the decarboxylation enthalpy, thereby facilitating rapid generation of active radical species. Furthermore, F-OXEs demonstrate significantly improved photoinitiation efficiency compared to the nonfluorinated analogue, affording high double-bond conversions under LED irradiation at 365, 385, and 405 nm as well as under sunlight, with an overall trend of increasing efficiency as the degree of fluorination increases. Moreover, a two-component system composed of F-OXE-TPA and an iodonium salt enables efficient deep curing under LED@405 nm irradiation with a curing depth of up to 38.5 mm. All F-OXEs exhibit low migration in the cured polymers, with F-OXE-TPA demonstrating the best migration stability. These results demonstrate that the introduction of fluorinated substituents is an effective strategy to enhance the performance of chalcone-based oxime ester photoinitiators and provides guidance for the design of high-performance photoinitiators for LED-driven photopolymerization.

Liquid-phase adsorption is a critical technology for environmental sustainability, resource management, and the advancement of biotechnology and materials science. The development of materials capable of efficient and highly selective adsorption from aqueous media is essential. In this study, we investigate the adsorption of phenolic compounds (guaiacol, creosol, and homocresol) from aqueous solutions using a stable hydrophobic metal-organic framework (MOF), namely MIL-140C. Synthesized via fast microwave-assisted hydrothermal conditions within 40 min, MIL-140C exhibits high efficiency in liquid-phase separations, achieving full recovery of these compounds upon complete pore occupancy. Our results highlight that the adsorbent with one-dimensional (1D) channels featuring parallel benzene rings is superior; the micropore filling degree of the adsorbent directly affects the recovery efficiency of the adsorbate. Theoretical calculations and Fourier transform infrared spectroscopy (FTIR) analysis further confirm the adsorption with minimal chemical bonding. This study underscores the potential of MOFs of benzene rings parallel to the 1D channel for sustainable phenolic recovery and efficient separations of aromatic containing molecules, reflecting the decisive importance of micropore occupancy in determining recovery efficiency.

Confinement of metal species in porous supports is an effective strategy to optimize hydrogenation performance ascribing to tunable nanopore environments. However, only focusing on the electronic structure modulation for metal species has limited the design of improved catalysts. Herein, spatial confinement strategy is reported for constructing ultrasmall metal clusters in nitro-bonded COF (M@TpPa-NO2, M = Pd, Pt, Ru, Rh, Ir). Thereinto, Pd@TpPa-NO2 can achieve efficient co-catalytic alkyne semi-hydrogenation by the organic nitro units and the Pd clusters, with an outstanding phenylacetylene hydrogenation activity of TOF = 13756 h-1 and a high 94% styrene selectivity under 25 degrees C and 1 bar H2. In situ diffuse reflectance infrared Fourier transform spectroscopy and density functional theory calculations confirm that the H2 dissociation occurs at Pd clusters and the nitro groups accept spilled H atoms for subsequent semi-hydrogenation. The facile styrene desorption from TpPa-NO2 support contributes to a high semi-hydrogenation selectivity. This work provides new perspectives for designing efficient catalysts with overcoming the activity-selectivity trade-off in selective hydrogenation reactions.

The facile synthesis of highly substrate‐adapted catalysts with dynamic active site adaptability remains a persistent challenge in heterogeneous catalysis. Herein, breaking through conventional catalyst preparation route of design–synthesis–evaluation iteration, we demonstrate an active site self‐evolving reconfiguration strategy for spontaneous construction of an adaptive multimolecular activation catalyst, such as for acetylene semihydrogenation. Specifically, a metastable Cu single atom (Cu 1 ) precursor as structural seed reconstructs to an exceptional acetylene semihydrogenation catalyst under moderate operational conditions, which undergoes a copper active site reconfiguration employing reactants themselves as inducing medium. This self‐evolving reconfiguration creates cooperative Cu 1 and Cu nanocluster (Cu n ) ensemble sites with a dynamic active configuration, which is unavailable by conventional thermal reduction methodology, for adaptive multisubstrate H 2 and acetylene activation. Hence, the resulting catalyst achieves full acetylene conversion with 96% ethylene selectivity and robust durability (>30 h) at a record‐low temperature of 120 °C, superior to reported copper‐based analogues. Such spontaneous active site self‐evolving reconfiguration offers a new possibility for intelligent catalyst engineering.

Heavy metal cadmium causes significant contamination in aquatic ecosystems. The biomineralization of cadmium represents a vital biological mechanism for handling cadmium stress in diverse microorganisms. To improve the biomineralization capacity of cadmium by microorganisms in aquatic environments, Tetrahymena cysteine synthetase 1 (TtCsa1) was overexpressed in E. coli. The tolerance of E. coli/pET-28a-TtCSA1 to cadmium was enhanced by expressing TtCsa1. Upon addition of cysteine, E. coli/pET-28a-TtCSA1 generated more H2S, which reacted with Cd2+ to form CdS quantum dots (QDs), resulting in a stronger fluorescence signal. The UV-visible absorption and fluorescence spectra of the culture supernatant of E. coli/pET-28a-TtCSA1 showed characteristic peaks corresponding to CdS QDs. Transmission Electron Microscopy (TEM) images confirmed that the formation of CdS QDs and their agglomeration in the E. coli cells. X-ray Diffraction Analysis (XRD) analysis further confirmed the presence of QDs and their crystalline nature. In rich medium, E. coli/pET-28a-TtCSA1 achieved removal rates of 99.5%, 98.2%, 56.5%, and 49.4%, respectively, for Cd2+ concentrations of 0.15, 0.3, 0.45, and 0.6 mM within 48 h. In simulated wastewater, E. coli/pET-28a-TtCSA1 achieved removal rates of 99.4%, 94.3%, 90.1%, and 89.8%, respectively, for Cd2+ concentrations of 0.3, 0.45, 0.6, and 0.75 mM within 12 h. These results demonstrate that overexpressing TtCsa1 in E. coli can significantly enhance its ability to biomineralize Cd2+ in rich medium and simulated wastewater, which has potential applications in bioremediation of aquatic environments contaminated with heavy metals.

Radioactive iodine from nuclear energy poses serious risks to aquatic environments, driving the need for efficient adsorbents for nuclear wastewater treatment. Metal-organic frameworks (MOFs) have shown promise in iodine capture due to their tunable pores and functional surfaces. In this work, three copper-triazolate-based MOFs with unsaturated coordination (CuCl2(TRZ) for 1, Cu4OCl3(TRZ)3 for 2, Cu3HOCl2(TRZ)3·2.4H2O for 3; TRZ = 1,2,4-triazole) were synthesized and characterized. Compound 1 exhibits a one-dimensional chain structure, compound 2 exhibits a two-dimensional layer, and compound 3 exhibits a three-dimensional cage architecture featuring a 10 Å molecular cage with two kinds of window sizes at 5 and 7.8 Å, respectively. In the evaluation of iodine adsorption in aqueous solution, compound 3 demonstrated outstanding iodine adsorption, removing 95% of iodine from aqueous solution within 200 min and maintaining high efficiency and structural stability over four adsorption-desorption cycles. This study offers a new strategy for designing radioactive iodine adsorbents and enhances the understanding of interactions between unsaturated metal sites and iodine species.

The conventional synthesis of fine chemicals through multi-step independent reactions frequently necessitates intermittent catalyst substitution and laborious intermediate purification, posing significant challenges to process efficiency and energy sustainability. Herein, we developed a polyoxometalate (POM)-mediated defect engineering strategy to construct a spatially isolated but functionally coupled oxidation-amination dual-active sites by confining H5PV2Mo10O40 ({PV2Mo10}) in UiO-66 ({PV2Mo10}- 0.1@UiO-66), achieving a one-pot two-step tandem conversion of alkenes to amino alcohols. The complete conversion process begins with {PV2Mo10}-catalyzed highly selective epoxidation of the alkenes (step A), followed by the in situ ring-opening amination of the epoxide intermediate by direct addition of the amine under the catalysis of the defective sites on UiO-66, without catalyst replacement and intermediate separation. Spectroscopic and catalytic performance analysis confirmed that the {PV2Mo10}-0.1@UiO-66 with dual-active sites has continuous reaction and multi-cycle structural stability. Based on the rich functionality of POMs and metal-organic frameworks (MOFs), their diverse assembly will provide a modular design platform for catalyst design aimed at tandem reactions.

Enhancing intrinsic activity and increasing catalytic site density are two widely employed strategies to improve catalytic performance. Although typically considered independently, their interplay remains poorly understood. Here, two UiO-66 metal-organic frameworks (MOFs) with distinct catalytic site densities-linker-defective UiO-66L and cluster-defective UiO-66C-are synthesized and systematically compared. Despite a higher density of open Zr catalytic sites, UiO-66L exhibited lower catalytic activity than UiO-66C across four model reactions, performing similarly to defect-free UiO-66. Although defect engineering is expected to enlarge pore connectivity, diffusion-ordered spectroscopy (DOSY) and molecular dynamics (MD) simulations surprisingly reveal that UiO-66C exhibits similar diffusion rates to defect-free UiO-66, while UiO-66L shows significantly slower diffusion. This discrepancy is attributed to self-adsorption of reactants at the high-density catalytic sites, which induces local diffusion resistance even in the presence of expanded channels. These findings reveal a performance trade-off between catalytic site density and intrinsic activity, establishing a critical threshold beyond which further increases in site density can hinder rather than enhance catalysis.

Titanium-based metal-organic frameworks (Ti-MOFs) hold great potential for applications in photocatalysis and other fields, owing to Ti's abundant reserves, low toxicity, and excellent photocatalytic and redox activity. However, Ti's strong affinity for oxygen often leads to Ti-MOFs being fully coordinated with ligands, which limits their catalytic and separation performance. Defect engineering provides an effective strategy to enhance the functionality of MOFs by introducing structural imperfections. Despite this, the synthesis of new Ti-MOFs and the incorporation of defects remain challenging due to the complex hydrolysis and reaction processes of Ti precursors and the uncertainty of Ti cluster formation. This review categorizes Ti-MOFs according to their diverse cluster structures, which play a key role in the development of new frameworks and defect engineering. It also examines various defect construction methods and their applications. Finally, insights from defect-engineered Zr-MOFs are discussed to inspire future advancements in the synthesis and application of defective Ti-MOFs.

The strategic introduction of defects in polyoxometalate-based metal-organic frameworks (POM@MOFs) enables synergistic catalytic effects between POMs and defect sites, achieving catalytic functions unattainable by either component alone. However, the complexity of the POM@MOFs synthetic system makes the controlled construction of defects more challenging than in conventional MOFs. Herein, we develop an atomic substitution-modulated host-guest interaction strategy for controlled synthesis of electron-deficient defect sites in POM@MOFs with tunable missing-linker content. Specifically, the gradual substitution of Mo atoms with V atoms in H3PMo12O40 (PMo12) enhances the nucleophilicity of surface oxygen species, thereby strengthening the interaction between POMs and Zr6-oxo clusters in UiO-67. This enhanced interaction induces varying degrees of ligand loss through coordination competition of POMs with organic ligands during the self-assembly of POM@UiO-67. Meanwhile, POMs acting as electron sponges withdraw electrons from UiO-67, resulting in lower electron density at defect sites compared to traditional defective UiO-67. The induced defect sites exhibit superior catalytic performance in the transfer hydrogenation of cinnamaldehyde, due to a significantly reduced hydrogen transfer energy barrier. This work provides a new perspective for designing crystalline porous catalysts with synergistic effects based on the modulation of host-guest interaction.

Mixed-linker strategies combined with selective etching enable precisely introduce defects into metal-organic frameworks (MOFs). However, random linker distributions in most mixed-linker systems limit control over the type and spatial arrangement of defects. Here, a unique MOF, Zr6(BDC)3(Fum)3, featuring crystallographically ordered terephthalic acid (BDC) and fumaric acid (Fum) linkers, is designed as a model to study ordered defect generation. Due to the distinct chemical stability between aromatic and alkenyl linkers, both thermal etching and ozonolysis are employed to selectively remove Fum linkers. While direct thermal treatment caused partial framework collapse, although ozone oxidation is impossible to completely remove Fum, it provides a milder pathway that preserved crystallinity. Combined ozonolysis-thermal treatment strategy enabled the gradual removal of Fum linkers, generating controllable missing-linker defects. Catalytic evaluation using the ring-opening of styrene oxide reveals a volcano-type correlation between defect density and activity: the conversion rate increased with defect number up to approximately two missing linkers per cluster, beyond which framework degradation led to reduced catalytic performance. This work demonstrates an effective strategy for constructing ordered single-type defects in MOFs and highlights the fundamental limitation of defect tolerance in the UiO-type framework.

The inherent sluggish kinetics of the conventional four-electron transfer pathway fundamentally limits the oxygen reduction reaction (ORR) efficiency. While electronic structure modulation offers potential solutions, developing effective catalytic regulation strategies remains challenging due to elusive structure-activity correlations. In this study, Fe4 cluster sites are engineered with dual parallel electron transfer channels that enable concurrent O─O bond cleavage and dual oxygen atom protonation. This unique configuration facilitates an optimized two-step double electron transfer mechanism, significantly enhancing ORR kinetics. Synergistic Mn single atom sites, strategically positioned as electron reservoirs, substantially elevate the electron density of Fe4 clusters while reinforcing Fe─N coordination bonds through charge redistribution. Remarkably, the spatial configuration of Fe4 clusters at the support periphery minimizes steric confinement effects, allowing simultaneous product desorption and oxygen adsorption - a critical advantage for sustaining continuous catalytic cycles. Through combined experimental and theoretical analyses, it is demonstrated that this dual-channel electron transport system effectively reduces activation barriers for elementary steps while accelerating charge transfer kinetics. This fundamental study establishes a new paradigm for designing high-performance ORR catalysts through multi-site collaborative engineering and reaction pathway optimization.

Organic long-lived phosphorescent materials demonstrating ultra-long photoluminescence have practical advantages owing to their flexible design and easy processability. However, the exact photophysical process underpinning the persistent-luminescent continues to elude full understanding, and the principles governing the compatibility of hosts and guests remain elusive. In this work, a new type of nonradiative energy transfer mechanism is proposed for the bi-component RTP system. Different from Förster resonance energy transfer or Dexter-type energy transfer, this energy transfer mechanism primarily relies on a triplet exciplex to exchange the electron. This facilitates the formation of triplet excitons that are otherwise difficult to excite directly. An evaluation methodology is devised to gauge the potential of a specific dopant-host combination toward generating pronounced afterglow. According to this framework, the enhancement of the afterglow is proportional to the decrease in the activation energy (Δ G ≠ ) associated with the electron transfer reaction between the dopant and the host. Notably, when the Δ G ≠ too larger, no observable afterglow occurs, as higher Δ G ≠ values significantly impede the electron transfer reaction between the two components. Furthermore, the remarkable dependence of afterglow intensity on the dopant concentration renders the bi-component RTP system highly promising for applications requiring ultra-high sensitivity and broad-spectrum detection capabilities.