Search Results (2,020)

Mining activities release radionuclides and toxic heavy metals into aquatic systems, creating long-term risks to water quality, ecosystems, and human health. Conventional remediation technologies often show limited effectiveness in mining-impacted waters due to complex geochemical conditions, including high salinity, variable pH, and co-occurring contaminants. This review evaluates non-graphene nanomaterials as emerging tools for mitigating radionuclide and heavy metal contamination, focusing on magnetic nanoparticles, metal oxides, nanoclays and zeolites, metal organic frameworks (MOFs), and biogenic nanoparticles. Graphene-based nanomaterials are excluded from the present review because they have been comprehensively addressed in a dedicated review previously published by the authors. A comparative evaluation of these nanomaterial classes demonstrates that no single material is universally optimal; rather, remediation performance depends on contaminant speciation, water chemistry, and operational requirements. Emphasis is placed on the mechanistic processes governing contaminant removal, including ion exchange, surface complexation, chemisorption, physisorption, and photocatalytic redox reactions. The role of environmental factors such as pH, ionic strength, competing ions, and natural organic matter in controlling nanomaterial performance is critically assessed. While laboratory studies demonstrate high removal efficiencies, practical implementation remains constrained by nanoparticle aggregation, long-term stability, recovery, and scalability under realistic mining-water conditions. The review highlights composite materials, immobilized nanostructures, green synthesis routes, and hybrid treatment systems as viable pathways for field deployment. This work underscores the importance of mechanistic insight and environmental compatibility in translating nanomaterial-based remediation strategies from laboratory research to sustainable water management solutions in mining-impacted environments. Full article

Coal-fired power generation remains a major source of carbon dioxide (CO₂) emissions, and metal–organic framework-74 (MOF-74) materials offer high adsorption capacity but rely on costly 2,5-dihydroxyterephthalic acid linkers that limit scalability. This study synthesized bimetallic Zn_0.75Mg_0.25-MOF-74 using terephthalic acid (TPA) as a cheaper alternative linker and evaluated the effect of synthesis reaction temperature (89–160 °C) and time (5–55.5 h) on its physicochemical properties for carbon capture. Samples were prepared solvothermally and characterized by FTIR, XRD, SEM-EDS, and N₂ (77 K) and CO₂ (293 K) adsorption analysis. FTIR confirmed metal–ligand coordination; XRD verified crystalline MOF-74 formation, and SEM showed well-defined rod-like morphology at 100 °C, 12 h and 125 °C, 30 h. Direct CO₂ adsorption on the 125 °C, 30 h sample yielded a Type I isotherm characteristic of micropore filling, with an uptake of 0.31 mmol/g at ~1 bar and 0.072 mmol/g at flue-gas-relevant conditions (~0.135 bar). Its CO₂-derived BET surface area (60.10 m²/g) and Dubinin–Astakhov micropore area (131.69 m²/g) far exceeded N₂-derived values, confirming ultra-micropores accessible to CO₂ but not to N₂ at 77 K. TPA therefore yields a stable, microporous CO₂-adsorbing framework, trading some capacity for lower cost and scalability. Future investigations should systematically evaluate long-term cycling stability and adsorption performance under mixed-gas operating conditions. Full article

The oxygen reduction reaction (ORR) remains a major bottleneck in terms of kinetics and durability in fuel cells and zinc–air batteries (ZABs). Metal–organic frameworks (MOFs) are versatile precursors for platinum-group metal (PGM)-free ORR electrocatalysts because their metal distribution, ligand chemistry, guest confinement, morphology, and porosity can be controlled before pyrolysis. This review examines how these precursor characteristics and subsequent thermal conversion govern metal migration; heteroatom retention; carbon ordering; pore evolution; and, ultimately, the nuclearity, coordination environment, and accessibility of the resulting active sites. Recent advances in conventional and asymmetric M–N_x single-atom sites, dual- and multi-atom sites, and single-atom–cluster or nanophase interfaces are critically evaluated, with particular attention to the evidence supporting structural assignments, activity, selectivity, and durability. Half-cell performance is further related to practical fuel-cell and ZAB operation by considering catalyst loading, ionomer or electrolyte contact, gas and water transport, and catalyst-layer degradation. Further progress will require simultaneous optimization of active-site structure, accessible-site density, hierarchical porosity, carbon stability, and electrode architecture, together with standardized testing protocols for reliable translation from rotating disk electrode measurements to working cathodes. Full article

NO₂ sensing is shifting from the optimization of individual receptor materials toward integrated systems in which surface chemistry, interfacial charge transfer, transducer architecture, operating environment, and regeneration jointly determine performance. This review argues that deployment readiness is set not by peak response but by the coupled performance of five layers: (i) receptor and interface chemistry, (ii) transducer and device architecture, (iii) gas delivery and environmental conditions, (iv) regeneration and aging, and (v) calibration, uncertainty, and system integration. Within this mechanism-to-deployment framework, we examine how oxygen adsorption, depletion and accumulation layers, heterojunction and Schottky barriers, defects, catalytic sensitization, and percolation govern the electrical signal across metal oxides, carbon materials, transition-metal dichalcogenides, MXenes, porous and MOF-derived architectures, and organic semiconductors and how MEMS microheaters, FET/TFT/MOSFET transducers, flexible platforms, optical and electrical regeneration, and AI-assisted arrays read it out. Despite this progress, translation remains limited by environmental interference, incomplete recovery, transport-dependent response, aging, and device-to-device variability so that record responses seldom survive realistic operation. Reliable NO₂ monitoring therefore requires application-specific validation of the complete measurement cycle—exposure, readout, recovery, environmental perturbation, calibration, and long-term operation—rather than isolated sensitivity metrics. Full article

Fabricating nanoscale metal–organic frameworks (MOFs) with hierarchical pores is an effective strategy to engineer high-performance adsorbents. Herein, hierarchically porous NH₂-MIL-53(Al) nanorods were synthesized through a straightforward one-pot solvothermal approach, featuring inherently interconnected micro-/mesoporous with an average pore width of 19.51 nm and abundant amino-functionalized active sites. Toward the anionic Direct Scarlet dye, the material delivers a Langmuir maximum adsorption capacity of 694.99 mg·g⁻¹, with its adsorption kinetics and isotherms well described by the pseudo-second-order kinetics and Langmuir isotherm model. Combined spectroscopic, thermodynamic, and diffusion analyses suggest monolayer electrostatic chemisorption between protonated –NH₃⁺ and dye sulfonate groups. The material exhibits favorable reusability, retaining over 85% of its original dye removal efficiency after five adsorption–desorption cycles, and PXRD and SEM results verify well-preserved morphology and crystalline lattice. This work clarifies the intrinsic correlation between structure and adsorption performance of NH₂-MIL-53(Al), offering a facile nanoscale pore-tuning strategy for the design and fabrication of high-performance MOF adsorbents. Full article

Antimicrobial resistance (AMR) presents a global health challenge that is projected to cause nearly 2 million deaths annually by 2050. With a growing ageing population and the rise of antibiotic-resistant strains globally, developing effective alternatives to combat infections while reducing AMR risks is critical. Over recent decades, antibiotic-free strategies have emerged as promising approaches, offering advantages over traditional antibiotics and reducing the likelihood of resistance. This review highlights antibiotic-free antimicrobial strategies for applications in chronic wound care, hard tissue repair, personal protective equipment, as well as hospital hygiene and infection control. We begin by outlining the broader AMR problem and then examine natural strategies—including the use of agents such as manuka honey—followed by synthetic approaches involving nanomaterials and metal–organic frameworks (MOFs), as well as biological and bioinspired antimicrobial strategies, involving antimicrobial peptides, antibodies, bacteriophages, extracellular vesicles, and macrocycles. Finally, we discuss innovations in artificial intelligence (AI)-assisted antimicrobial development and stimulus-responsive materials, before introducing a conceptual design framework for antibiotic-free antimicrobial materials. This review provides a comprehensive assessment of emerging antibiotic-free strategies to guide the development of next-generation antimicrobial solutions that reduce reliance on antibiotics and mitigate AMR in clinical and healthcare settings. Full article

Aqueous zinc-ion batteries are promising candidates for large-scale energy storage as high-safety, low-cost, and abundant zinc resources. Compared with conventional zinc foil, zinc powder (Zn-P) anodes display controllable capacity by regulating zinc powder loading, electrode thickness and pore structure, providing opportunities to improve zinc utilization, reduce costs and enhance manufacturing compatibility. However, Zn-P anodes are dynamic particle-composite electrodes in which reaction interfaces, pore channels, particle contacts, and electronic networks continuously evolve during cycling and storage. Their electrochemical behavior therefore reflects coupled effects of Zn²⁺ plating/stripping, hydrogen evolution, corrosion, by-product-induced pore blockage, stress evolution, contact loss, and calendar aging. This review focuses on the structural characteristics, failure mechanisms, interfacial reaction regulation, electrode engineering, and practical evaluation of zinc powder anodes. It subsequently analyzes the application boundaries of zincophilic metals, carbon materials, MXene, Meta–Organic Frameworks/Covalent Organic Frameworks (MOFs/COFs), artificial interphases, electrolyte additives, slurry engineering, current collectors, and manufacturing strategies. Then, it points out their mechanisms for regulating reaction selectivity, ion/electron transport, and structural stability. Further, the practical evaluation criteria are given, including Zn loading, the negative/positive capacity ratio (N/P ratio), Zn utilization, electrolyte dosage, calendar life and pouches/large-scale cells under limited zinc conditions. Overall, Zn-P anode development should focus on interfacial reaction selectivity, powder structure, electrode manufacturing and limited-zinc evaluation. Full article

Total antioxidant capacity (TAC) reflects the collective ability of biological systems to counteract oxidative stress and is therefore an important indicator in redox biology, nutritional evaluation, and clinical assessment. Conventional TAC assays often suffer from insufficient sensitivity, pronounced matrix interference, and limited reliability in complex biological samples. Herein, we developed a redox-active lanthanide metal–organic framework (CeMOF@Tb) through mild aqueous-phase synthesis followed by post-synthetic incorporation of Tb³⁺ ions, serving as a luminescent probe for sensitive and reliable TAC analysis. The reversible Ce⁴⁺/Ce³⁺ redox couple serves as the antioxidant-responsive recognition unit, while Tb³⁺ provides a characteristic green luminescence output. The antioxidant-mediated reduction of Ce⁴⁺ to Ce³⁺ regulates the energy transfer process, thereby producing a concentration-dependent enhancement in Tb³⁺ emission and reduction in Ce³⁺ fluorescence. The sensing platform also exhibits high selectivity and strong resistance to interference from common coexisting species, supporting reliable TAC determination in complex biological matrices. Furthermore, the probe was applied to human serum samples, yielding recoveries of 91.6–122.6%. This study establishes an integrated redox-to-luminescence transduction strategy for TAC analysis and provides a versatile design framework for developing Ln-MOF-based probes for clinical biochemical applications. Full article

The selective photocatalytic reduction of O₂ to H₂O₂ is an attractive route for sustainable H₂O₂ synthesis, yet its efficiency is often limited by the sluggish charge separation and insufficient selectivity of the two-electron oxygen reduction reaction. Here, we develop a conductive 2D Cu₃(HHTP)₂ metal–organic framework (MOF) in which Cu²⁺ sites serve as dynamic redox centers to regulate interfacial electron transfer and O₂ activation. Upon photoexcitation, photogenerated electrons are preferentially transferred to Cu centers, inducing reversible reconstruction of the local Cu coordination environment. Benefiting from the extended π-conjugated framework and strong interlayer electronic coupling, the accumulated electrons can delocalize over the 2D sheets, facilitating charge separation and suppressing electron–hole recombination. Spectroscopic and theoretical investigations further reveal that the dynamically reconstructed Cu sites promote O₂ adsorption and activation through electron donation from Cu d orbitals to O₂ antibonding states, thereby stabilizing the O₂⁻ intermediate and favoring the two-electron reduction pathway toward H₂O₂. As a result, the Cu₃(HHTP)₂ photocatalyst achieves an H₂O₂ evolution rate of 3910 μmol g⁻¹ h⁻¹ under visible-light irradiation. These findings demonstrate that dynamically regulated Cu electronic structures provide an effective strategy for coupling charge-carrier management with selective O₂ activation, offering a rational approach to the design of conductive 2D photocatalysts for efficient H₂O₂ photosynthesis. Full article

Volatile fluorinated compounds (VFCs) are indispensable to modern industry, yet their potent greenhouse effects pose critical environmental challenges. Functional porous materials, ranging from zeolites and semiconductor oxides to metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and other advanced porous materials, have emerged as versatile platforms for VFC sensing and capture, leveraging their structural tunability, ultrahigh surface areas, and designable pore chemistry. This review provides a systematic summary of recent advances in porous materials for VFC management. For sensing, we examine transduction mechanisms (chemiresistive, optical, and gravimetric approaches) with emphasis on structure–signal relationships. For capture, we evaluate adsorptive performance across VFC subclasses, highlighting design principles that govern selectivity and capacity. Based on recent achievements, we assess persistent gaps between laboratory-scale achievements and practical deployment. Possible pathways toward integrated sense-and-capture systems are also explored. By bridging fundamental materials science, this review highlights cross-cutting design strategies that may accelerate the development of next-generation VFC management platforms. Full article

Conventional biosensor coatings face considerable challenges in reconciling high loading capacity, antifouling performance, and long-term stability. Metal–organic frameworks (MOFs), with their ultrahigh surface areas, tunable pores, and abundant unsaturated metal sites, have become important functional coating materials for advanced sensing interfaces. This review focuses on interface engineering strategies for MOF-based biosensor coatings and systematically compares three core construction approaches, namely defect engineering, MOF-on-MOF heterostructures, and interface-assisted fabrication, examining their distinct interfacial regulation logics and applicability under engineering constraints including substrate compatibility, film uniformity, and scalability. The multifaceted interfacial roles of MOF coatings are then categorized across electrochemical, photoelectrochemical, colorimetric, optical fiber, and dual-signal biosensors, covering enrichment-confinement, catalytic transduction, biorecognition protection, and smart gating. Notably, most reported systems remain at the proof-of-concept stage, with insufficient validation in complex biofluids, ambiguous signal transduction mechanisms, and a notable deficiency in systematic assessments of coating adhesion and durability. Future efforts should focus on establishing standardized failure evaluation protocols, adopting AI-driven rational design, and advancing toward multi-target integrated and flexible wearable platforms to bridge the gap between laboratory research and practical diagnostic applications. Full article

Cellulose-based functional materials have attracted increasing attention for portable environmental monitoring and pollutant management; however, achieving a robust integration of functional components with cellulose substrates remains challenging due to weak interfacial adhesion and instability of conventional coating strategies. Herein, a binder-free liquid-phase epitaxy (LPE) strategy was developed to construct lanthanide metal–organic framework (Ln-MOF) coatings directly on unmodified cellulose fibers, yielding a stable and multifunctional Ln-MOF/cellulose composite material. The LPE process enabled uniform growth of Ln-MOF layers on cellulose paper, resulting in homogeneous luminescence with relative standard deviations below 2% and stable fluorescence performance over a wide pH range of 3–11. By regulating the Eu³⁺/Tb³⁺ ratio, the obtained composite paper exhibited tunable dual-emission characteristics and enabled smartphone-assisted ratiometric visualization of dipicolinic acid (DPA), a representative biomarker of bacterial spores, with a linear response range of 0–2000 μM and a detection limit of 10 μM. Furthermore, the anionic Ln-MOF coating endowed the cellulose material with charge-selective adsorption capability, allowing efficient removal of cationic dyes while maintaining structural integrity after four regeneration cycles. The applicability of the LPE strategy was further demonstrated using different lanthanide–organic linker systems. This work provides a versatile approach for fabricating stable cellulose/MOF composite materials and highlights their potential applications in portable chemical sensing and selective water purification. Full article

Background: Perfluorooctane sulfonate (PFOS) is a globally recognised persistent, bioaccumulative and toxic pollutant. Under China GB 5749-2022 and the US EPA 2024 drinking water MCL, permissible levels have fallen to 40 ng L⁻¹ and 4 ng L⁻¹, respectively, placing unprecedented demands on remediation technologies. Methods: An iron(III)–carboxylate metal–organic framework prepared from low-cost precursors (denoted MOF-LC, [Fe₃O(BDC)₃Cl]·x(solvent)) was synthesised via a one-pot solvothermal route from FeCl₃·6H₂O and terephthalic acid (H₂BDC). The material was characterised by PXRD, N₂ adsorption, FTIR, TGA, XPS, elemental analysis and ICP-OES. Adsorption performance was evaluated under varying initial concentrations, contact times, pH values, coexisting inorganic anions (Cl⁻, NO₃⁻, SO₄²⁻, HCO₃⁻, PO₄³⁻) and humic acid backgrounds, and by a panel of six water matrices. Results: MOF-LC exhibited a BET surface area of 1528 m² g⁻¹ and a dominant pore centred at 1.9 nm, which is geometrically compatible with the 1.36 nm molecular length of PFOS. Adsorption reached ≈95% of equilibrium capacity within 30 min and was best described by the pseudo-second-order model (R² = 0.998). Measured uptake reached 800.6 mg g⁻¹ at 298 K, corresponding to a Langmuir maximum capacity of 802 mg g⁻¹ (note that all adsorption experiments were conducted at mg L⁻¹ concentrations, several orders of magnitude above the regulatory limits cited above). Removal exceeded 88% across all six water matrices. PFOS removal efficiency fell from 99.2% to 85.8% over seven adsorption–regeneration cycles using a 1% NH₄Cl/methanol eluent, with 90.6% of the initial BET surface area retained and Fe leaching below 45 µg L⁻¹. Conclusions: Electrostatic, hydrophobic and pore confinement contributions are proposed as cooperative interpretations consistent with the observations. MOF-LC is identified as a technically promising laboratory-scale sorbent for PFOS removal from complex water matrices. Performance at environmentally relevant ng L⁻¹ concentrations and economic viability at scale remain to be established. Full article

Selective aerobic oxidation of styrene to value-added oxygenated products remains challenging because of the limited activity and difficult recovery of many homogeneous catalysts. Herein, an N,N′-dihydroxypyromellitimide (NDHPI)-functionalized Cu–Co bimetallic metal–organic framework (MOF), denoted NDHPI/Cu₁–Co₃–MOF, was constructed through an impregnation strategy to combine NDHPI-derived oxidation activity with accessible sites in a recoverable porous solid. Structural characterization supported the incorporation of NDHPI without loss of the principal crystalline features of the framework. Under the optimized conditions, the material afforded 81.94% styrene conversion with 73.5% selectivity toward styrene oxide at 80 °C under continuous molecular-oxygen supply and solvent-free conditions. The composition- and loading-dependent activity trends support complementary material-level contributions from the introduced NDHPI species and the mixed Cu/Co environment. In one sequence of four consecutive uses, styrene conversion decreased from 81.94% to 64.28%, while styrene oxide selectivity changed from 73.50% to 70.17%. Full article

Metal–organic frameworks (MOFs) have significant potential in electrochemical sensors, but the guest molecules and residual solvents in the pores often block the active sites and limit the reaction kinetics. One-dimensional nanostructures can provide direct conduction pathways and shorten ion diffusion distances, thereby enhancing electron transport and electrode contact. Meanwhile, fluorine-incorporated MOF materials leverage the high electronegativity of fluorine to substitute oxygen, suppress oxidation to widen the voltage window, and improve stability through enhanced hydrophobicity. In this work, 4-fluorosalicylic acid (4FSA) was used as the ligand and benzimidazole (Bim) was introduced to adjust the coordination environment, and one-dimensional Bim4FSA-MOF nanorods were successfully constructed. While the guest molecules were largely removed, the nickel sites were thereby activated and the pore size was enlarged. Due to the synergistic effect of one-dimensional nanostructure-promoted electron transport and the Ni(OH)₂/NiOOH dynamic active center, the B-250 composite exhibited excellent performance in a glucose electrochemical sensor. The optimized sensor delivered a detection limit of 0.022 μM and a detection time of 0.9 s, along with a sensitivity value of 2986.45 μA mM⁻¹ cm⁻², which provides a new strategy for the design of efficient MOF-based electrochemical sensor interface. Full article