Search Results (102)

Metal–organic frameworks (MOFs) exhibit high specific surface area and porosity, which may facilitate electron transfer during electrochemical reactions. Therefore, it is clear that MOFs are promising materials for the development of electrochemical sensors. In particular, zinc (Zn) based MOFs offer several advantages such as high specific surface area, porosity, environmental friendliness and low cost. Thus, Zn-based MOF materials and their composites have been extensively utilized in the detection of various pollutants, biomolecules and food additives. The Zn-MOF-based materials have been extensively utilized in electrochemical and fluorescence sensing applications. Previously, various Zn-MOF-based sensing systems such as pristine Zn-MOF, carbon-supported Zn-MOF composites, MXene hybrids with Zn-MOF, and bimetallic/trimetallic Zn-based MOFs were explored to enhance sensing performance. Such materials exhibit remarkable analytical performance, such as a low limit of detection (LOD) (nM to pM range), wide linear response range (LR), fast response times, and high selectivity in the presence of interfering species. In electrochemical sensing, Zn-MOF-modified electrodes demonstrated improved charge-transfer kinetics and sensitivity, enabling accurate determination of the biomolecules, drugs and heavy metal ions in real samples. Similarly, Zn-MOF-based fluorescence sensors showed high luminescent properties and displayed sensitive detection of pollutants and biomolecules. Despite such promising sensing performances, some challenges, such as low stability, reproducibility and selectivity in real-time monitoring, etc., remain that need to be overcome. This review article summarizes the previously reported literature on the fabrication of Zn-MOFs, their composites and Zn-MOF-derived materials for the development of electrochemical and fluorescence sensors. We have also discussed the future directions for the rational design of the high-performance Zn-MOF-based sensing systems for environmental and biomedical applications. We believe that the present review article would be useful for the scientific community working on the fabrication of Zn-MOF-based sensors. Full article

High-performance polyethersulfone (PES) ultrafiltration membranes integrating antibacterial activity and antifouling performance were fabricated via the in situ construction of bimetallic polyphenol networks (BMPNs) throughout the membrane architecture. Tannic acid (TA) functioned as a multifunctional molecular bridge, functionalizing silver metal–organic frameworks (Ag-MOFs) to yield hydrophilic T-Ag-MOFs and chelating Fe³⁺ ions from the coagulation bath to form a polyphenol network during phase inversion. T-Ag-MOF incorporation generated asymmetric morphologies featuring highly porous surfaces and sponge-like cross-sections, improving pure water permeability, mechanical integrity, and bovine serum albumin (BSA) rejection. TA-mediated functionalization increased hydrophilicity, imparted a negative surface charge, suppressed nonspecific protein adhesion, and enhanced flux recovery with low irreversible fouling. At an optimal loading of 0.4 wt%, the resultant T-Ag-MOF/Fe³⁺/PES composite membrane achieved a pure water permeability of 593.4 L m⁻² h⁻¹ bar⁻¹—1.77-fold higher than that of the pristine PES control—while sustaining a BSA rejection of 96.5%. Notably, interfacial compatibility between the T-Ag-MOFs and PES matrix was enhanced, facilitating strong, covalent-like filler–matrix adhesion. Moreover, the composite membrane delivered synergistic multifunctionality, including exceptional long-term aqueous stability, precisely tuned Ag⁺ release kinetics, and potent antibacterial activity, as evidenced by negligible uncontrolled ion leaching and a lack of structural degradation under prolonged hydration. Full article

To address the critical challenges of sluggish C-C coupling kinetics and the propensity for over hydrogenation to ethane (C₂H₆) in the photocatalytic CO₂ reduction to ethylene (C₂H₄), this study designed a synergistic bimetallic Pt/Co cluster catalyst supported on a covalent organic framework (COF), designated as PtCo-TpBD COF. This catalyst is designed to modulate the adsorption of key intermediates via Co clusters to suppress over-hydrogenation, while leveraging Pt clusters to promote C-C coupling, thereby achieving highly selective C₂H₄ production. Through a series of structural characterization analyses, it was confirmed that Pt/Co clusters were successfully confined within the pores of the COF, and significant electronic interactions were observed. In situ infrared spectroscopy revealed that the introduction of Co clusters effectively weakens the adsorption strength of the CO* intermediate, while the incorporation of Pt clusters promotes C-C coupling. In visible-light-driven gas-phase CO₂ reduction, this catalyst delivered exceptional activity, reaching an C₂H₄ formation rate of 7.54 μmol g⁻¹ h⁻¹ and an C₂H₄ selectivity of 90.1%, along with remarkable inhibition of deep hydrogenation byproducts including C₂H₆. This study not only provides a successful example for constructing efficient bifunctional photocatalysts to achieve highly selective conversion of CO₂ to C₂H₄, but also highlights the great potential of COFs as advanced platforms for integrating multifunctional metal clusters and precisely tuning catalytic selectivity. Full article

Manganese-based cathodes offer high capacity, low cost, and safety for aqueous zinc-ion batteries (AZIBs), yet suffer from Mn dissolution, Jahn–Teller distortion, and sluggish Zn²⁺ kinetics. Herein, a Zn/Co co-doped MnO nanoporous carbon composite (denoted as ZnCo-MnO@NPC) derived from a bimetallic ZnCoMn metal–organic framework (ZnCoMn-MOF-74) is successfully synthesized and proposed as a high-performance cathode to address these challenges. The introduction of Zn²⁺ increases the initial specific capacity of MnO, while Co doping effectively suppresses the Jahn–Teller distortion and improves the integrity of the structure. Furthermore, the nanoporous carbon matrix facilitates electrolyte infiltration and accelerates ionic transport. To further suppress dendrite growth and enhance cycling stability, a zeolitic imidazolate framework (ZIF-8) protective layer is engineered on the zinc anode (denoted as ZIF-8@Zn), effectively mitigating dendrite formation. The ZnCo-MnO@NPC//ZIF-8@Zn full cell demonstrates superior electrochemical performance, delivering 281.3 mAh g⁻¹ at 0.1 A g⁻¹ and retaining 98.7% of this value after 3500 long-term cycles at 2.0 A g⁻¹, a remarkable finding that underscores its potential for high-performance energy storage. Collectively, this work highlights that transition metal ion doping represents an effective way to design efficient high-performance MOF-derived cathodes of AZIBs. Full article

Metal ion-based chemo-immunotherapy is often limited by rigid intracellular metal homeostasis, insufficient reactive oxygen species (ROS) accumulation, and an immunosuppressive tumor microenvironment (TME). To overcome these limitations, we engineered an ATP-responsive, core–shell bimetallic nanoreactor (Cu/ZIF@PDA, termed CZP) featuring a precisely controlled ~25 nm biomimetic polydopamine (PDA) coating. Triggered by elevated tumoral ATP levels, CZP undergoes coordination-induced disassembly and promotes oxidative stress amplification. Specifically, the PDA shell acts as a superoxide dismutase (SOD) mimetic to continuously supply H₂O₂, fueling Cu²⁺-mediated Fenton-like reactions to unleash highly toxic hydroxyl radicals (•OH) while aggressively depleting the intracellular glutathione (GSH) pool. This irreversible oxidative damage, coupled with Zn²⁺-induced mitochondrial dysfunction, triggers profound mitochondrial DNA (mtDNA) leakage. Crucially, this cytosolic DNA robustly activates the cGAS-STING signaling axis, driving a massive surge in immunogenic cell death (ICD) and significantly promoting dendritic cell (DC) maturation. Furthermore, CZP markedly inhibited primary tumor growth in vivo and showed protection in a tumor re-challenge model, accompanied by enhanced dendritic cell maturation. These findings support the potential of this ATP-responsive bimetallic nanoplatform to promote antitumor immune activation. Full article

Arsenic pollution is a prevalent challenge worldwide due to extensive use dating back thousands of years, and the pentavalent species arsenate (As(V)) is of particular interest because it predominates in oxygenated groundwater. Metal–organic frameworks (MOFs), characterized by their high surface area and tunable surface chemistry, have emerged as promising adsorbents for its rapid and efficient removal. This study systematically evaluated the adsorption performance, physicochemical properties, and regeneration behavior of monometallic Fe-BTC MOF and bimetallic Fe/Cu-BTC for As(V) removal under application-relevant conditions. Fe-BTC exhibited the highest adsorption capacity of As(V) (117.5 mg g⁻¹), whereas Fe/Cu-BTC showed a lower capacity (74.6 mg g⁻¹). Adsorption in tap water decreased slightly for both materials (19–23%), indicating mild competition from coexisting ions. The adsorption behavior followed the Freundlich model, indicating competitive occupation of high-energy sites on Fe-BTC. In contrast, the surface heterogeneity of Fe/Cu-BTC remained unchanged, highlighting its robust characteristics. Adsorption was strongly pH-dependent, reaching a maximum at neutral pH, and regeneration experiments identified ethanol as the most effective desorption agent for Fe-BTC, enabling reuse. Metal-leaching analysis confirmed superior Fe-BTC MOF stability and minimal leaching, whereas Fe/Cu-BTC instability demonstrated risk of secondary Cu contamination. Overall, these findings establish that Fe-BTC and Fe/Cu-BTC MOF are effective for As(V) adsorption, but Fe-BTC outperforms Fe/Cu-BTC as a practical adsorbent. Significantly, Fe-BTC performance is strongly influenced by water matrix composition and regeneration solvent, highlighting considerations for real-world applications. Full article

This review analyzes the catalytic routes for the Power-to-X (PtX) conversion of hydrogen to methane, methanol, ammonia, formic acid, and synthetic hydrocarbon fuels. The key reactive synthesis technologies and catalysts for each vector are described. Recent studies and pilot projects summarizing the reaction pathways of each vector and the associated catalyst technologies are also discussed. The analysis indicates that catalyst selection critically influences the efficiency and selectivity of these reactive systems. Some catalyst synthesis routes rely on expensive critical minerals (e.g., Ru and Rh), which raise technical and economic challenges for their industrial application. Catalyst deactivation and scale-up limitations are also relevant issues to be resolved. Emerging catalysts (e.g., Fe–Co or Co–Ni bimetallics, core–shell materials, metal-organic frameworks (MOFs), electrides, covalent-organic frameworks (COFs), and perovskites) are being explored to enhance stability, selectivity, and deactivation. Europe leads PtX development to consolidate the industrial production of hydrogen-based vectors with strong policy support, while the industrial initiatives in Latin America are limited (for instance, Chile’s green methanol and ammonia projects are examples) despite its great potential to generate renewable energy. In summary, Power-to-X can store renewable energy and close the carbon loop; however, its industrial consolidation demands catalyst innovation and supportive regulatory frameworks to overcome the challenges highlighted in this review. Full article

To address the inherent limitations of Cu₂Se as a lithium-ion battery (LIB) anode, a Cu₂Se/MnSe@C composite was rationally designed and synthesized via selenization of a CuMn bimetallic metal–organic framework (MOF) precursor. This synthesis strategy integrates carbon composite engineering and heterogeneous structure construction, achieving in situ formation of Cu₂Se/MnSe heterogeneous nanoparticles anchored on amorphous carbon nanosheets. Structural characterizations confirm the successful construction of well-defined Cu₂Se/MnSe interfaces and uniform dispersion of selenide components, with Mn introduction inducing regulated electron transfer between Cu₂Se and MnSe. Electrochemical evaluations demonstrate that the Cu₂Se/MnSe@C composite exhibits a significantly enhanced lithium storage performance compared to single-component Cu₂Se@C, including higher specific capacity and superior rate capability. Mechanistic studies reveal that the synergistic effects of the carbon matrix (enhancing electrical conductivity and mitigating volume expansion) and the Cu₂Se/MnSe heterogeneous interface (lowering charge transfer resistance, accelerating Li⁺ diffusion, and boosting pseudocapacitive contribution) are responsible for the performance enhancement. Moreover, Cu₂Se/MnSe@C||LiFePO₄ full cells deliver a stable average operating voltage and reliable cycling stability, validating the composite’s practical application potential. Full article

Low-temperature (including room-temperature) gas sensors are crucial for energy-efficient and safe detection applications. In this study, we report the synthesis of In₂O₃-sensitized NiO nanoparticles (NPs) for NO₂ detection. The NiO/In₂O₃ hybrid materials were obtained by pyrolysis of Ni/In bimetallic metal–organic framework (MOF) nanosheets (NSs) fabricated through ultrasonic synthesis and cation exchange. Gas sensing tests revealed that the In₂O₃ sensitization significantly enhances the NO₂ sensing performance of NiO, enabling a response of 1.5 at room temperature (RT) and an optimal response at 100 °C. The NiO/In₂O₃ sensor demonstrates enhanced selectivity toward NO₂, an ultra-low detection limit (41 ppb), and long-term stability. This study presents an effective MOF-derived route for developing high-performance low-power gas sensors. Full article

Polydimethylsiloxane (PDMS) is commonly used in gas-separation studies because of its high CO₂ permeability and stable mechanical properties. In this work, mixed matrix membranes (MMMs) were prepared by incorporating the bimetallic MOFs Ni-Cu-MOF-74, Ni-Co-MOF-74, and Ni-Zn-MOF-74 into a PDMS matrix. The membranes were fabricated by solution casting and characterized by SEM, XRD, FT-IR, and BET analyses, which confirmed uniform filler dispersion and the successful incorporation of the MOF-74 structures. Single-gas permeation tests showed clear performance improvements with MOF loading. The best results were obtained for the membrane containing 1 wt.% Ni-Cu-MOF-74, which reached a CO₂ permeability of 3188.25 Barrer and a CO₂/N₂ selectivity of 35.10. The improvement is attributed to the accessible metal sites and high surface area provided by the MOF-74 framework, which enhanced adsorption–diffusion pathways for CO₂ transport. These results show that PDMS/MOF-74 mixed-matrix membranes are effective for CO₂/N₂ separation, with Ni-Cu-MOF-74 achieving the highest performance. Full article

The development of efficient, highly stable photocatalysts is essential to address the two challenges of environmental remediation and renewable energy. Structurally strong Zeolitic Imidazolate Framework-8 (ZIF-8) has intrinsic drawbacks, including a large bandgap and fast charge-carrier recombination. This paper presents a highly efficient approach to designing the optoelectronic behaviour of ZIF-8 via controlled nickel doping. Ni(x)-ZIF-8 (0, 2.5, 5, 7.5, and 10 mol, x), and bimetallic metal–organic frameworks were prepared via a simple room-temperature process. Through adequate characterization, the incorporation of Ni²⁺ into the ZIF-8 lattice has been demonstrated to be successful, resulting in substantial structural and electronic changes. Framework integrity was confirmed using XRD and FTIR analysis, which revealed increased microstrain and the formation of Ni-N bonds. Most importantly, UV-Vis spectrophotometry and electrochemical studies indicated that the bandgap was systematically narrowed: a pristine ZIF-8 had a high bandgap of 3.65 eV, and a Ni(10)-ZIF-8 had a low bandgap of 3.23 eV, while charge-transfer resistance was reduced significantly. All these synergies led to high photocatalytic performance. The best Ni(2.5)-ZIF-8 catalyst achieved a desirable result, degrading methylene blue to more than 98.5%, which was far superior to that of the pure framework. Moreover, the hydrogen evolution reaction (HER) showed higher electrocatalytic activity, with a significantly lower overpotential and higher current density. This article defines Ni doping as an effective route to convert ZIF-8 into a high-performance, dual-functional photocatalyst. It opens the door to implementing solar-powered environmental remediation and hydrogen generation using ZIF-8. Full article

In this work, a novel mixed-component bimetallic metal–organic framework (MOF) composite material was synthesized via a solvothermal approach, and its structural and textural properties were systematically characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), N₂ adsorption/desorption analysis, and transmission electron microscopy (TEM). Furthermore, the single-component adsorption isotherms of CO₂ and N₂ were experimentally measured and fitted to the Langmuir–Freundlich model. The CO₂/N₂ selectivity of the composite was evaluated based on the ideal adsorption solution theory (IAST). The results demonstrated that the addition of Zn²⁺ significantly enhanced the specific surface area and improved the CO₂ adsorption capacity (3.97 mmol/g at 35 °C and 1 bar), with an increase of 31.5% in comparison with the Cu-BTC/MCFs (3.02 mmol/g). Meanwhile, the Zn-Cu-BTC/MCFs had good recyclability and CO₂/N₂ selectivity up to 12.5 determined via IAST (CO₂:N₂ = 85:15). Full article

Iron-based catalysts for peroxymonosulfate (PMS) and peroxydisulfate (PDS) activation represent a cornerstone of advanced oxidation processes (AOPs) in environmental remediation, prized for their cost-effectiveness, environmental compatibility, and high catalytic potential. These catalysts, including zero-valent iron, iron oxides, and iron-organic frameworks, activate PMS/PDS through heterogeneous and homogeneous pathways to generate reactive species such as sulfate radicals (SO₄•⁻) and hydroxyl radicals (•OH). However, their large-scale implementation is constrained by inefficient iron cycling, characterized by sluggish Fe³⁺/Fe²⁺ conversion and significant iron precipitation, leading to catalyst passivation and oxidant wastage. This comprehensive review systematically dissects innovative strategies to augment iron cycling efficiency, encompassing advanced material design through elemental doping, heterostructure construction, and defect engineering; system optimization via reductant incorporation, bimetallic synergy, and pH modulation; and external field assistance using light, electricity, or ultrasound. We present a mechanistic deep-dive into these approaches, emphasizing facilitated electron transfer, suppression of iron precipitation, and precise regulation of radical versus non-radical pathways. The performance in degrading persistent organic pollutants—including antibiotics, per- and polyfluoroalkyl substances (PFASs), and pesticides—in complex environmental matrices is critically evaluated. We further discuss practical challenges related to scalability, long-term stability, and secondary environmental risks. Finally, forward-looking directions are proposed, focusing on rational catalyst design, integration of sustainable processes, and scalable implementation, thereby providing a foundational framework for developing next-generation iron-persulfate catalytic systems. Full article

To address the imbalance in energy supply and demand across different regions and seasons, the thermochemical conversion process was selected to efficiently utilize surplus energy. In the search for suitable novel materials, this study developed a porous matrix “in-salt” composite using a carbonized metal-organic framework as the carrier and LiCl as the primary reactant. When exposed to water vapor, the innovative material enabled both adsorption and desorption of water vapor, leading to the release and storage of thermal energy, thereby achieving effective energy storage. Using Zn(NO₃)₂·6H₂O and Co(NO₃)₂·6H₂O as metal ion sources and 2-methylimidazole as the ligand, bimetallic zeolitic imidazolate frameworks (BMZIFs) were fabricated via the liquid-phase precipitation method. The composite specimen prepared at a carbonization temperature of 1000 °C with a 20% LiCl mass concentration exhibited the most promising thermal storage performance, achieving the highest capacity, with a final water loss of 53.56% and a stable water adsorption capacity of about 0.831 g·g⁻¹. Full article

This paper provides a systematic review of the latest advancements in metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) for electrocatalytic carbon dioxide reduction. Both materials exhibit high specific surface areas, tunable pore structures, and abundant active sites. MOFs enhance CO₂ conversion efficiency through improved conductivity, optimized stability, and selective regulation—including bimetallic synergy, pulse potential strategies, and tandem catalysis. COFs achieve efficient catalysis through precise design of single or multi-metal active sites, optimization of framework conjugation, and photo/electro-synergistic systems. Both types of materials demonstrate excellent selectivity toward high-value-added products (CO, formic acid, C₂⁺ hydrocarbons), but they still face challenges such as insufficient stability, short operational lifespan, high scaling-up costs, and poor electrolyte compatibility. Future research should integrate in situ characterization with machine learning to deepen mechanistic understanding and advance practical applications. Full article