Fe-based Metal Research Articles

A facile approach to preparing personalized cancer vaccines using iron-based metal organic framework.

Considering the diversity of tumors, it is of great significance to develop a simple, effective, and low-cost method to prepare personalized cancer vaccines. In this study, a facile one-pot synthetic route was developed to prepare cancer vaccines using model antigen or autologous tumor antigens based on the coordination interaction between Fe3+ ions and endogenous fumarate ligands. Herein, Fe-based metal organic framework can effectively encapsulate tumor antigens with high loading efficiency more than 80%, and act as both delivery system and adjuvants for tumor antigens. By adjusting the synthesis parameters, the obtained cancer vaccines are easily tailored from microscale rod-like morphology with lengths of about 0.8 μm (OVA-ML) to nanoscale morphology with sizes of about 50~80 nm (OVA-MS). When cocultured with antigen-presenting cells, nanoscale cancer vaccines more effectively enhance antigen uptake and Th1 cytokine secretion than microscale ones. Nanoscale cancer vaccines (OVA-MS, dLLC-MS) more effectively enhance lymph node targeting and cross-presentation of tumor antigens, mount antitumor immunity, and inhibit the growth of established tumor in tumor-bearing mice, compared with microscale cancer vaccines (OVA-ML, dLLC-ML) and free tumor antigens. Our work paves the ways for a facile, rapid, and low-cost preparation approach for personalized cancer vaccines.

Iron-based metal-organic framework/graphene oxide composite electrodes for efficient flow-injection amperometric detection of dexamethasone.

A highly stable flow-injection amperometric sensor for dexamethasone (DEX) was developed using a pencil graphite electrode (PGE) modified with Fe-based metal organic frameworks, MIL-100(Fe) and graphene oxide composite materials (MIL-100(Fe)/GO). Scanning electron microscopy and energy-dispersive X-ray spectroscopy, transmission electron microscopy, powder X-ray diffraction, and Fourier-transform infrared spectroscopy were used to characterize the MIL-100(Fe) composites. The MIL-100(Fe)/GO-modified PGE (denoted MIL-100(Fe)/GO/PGE) was further electrochemically characterized using cyclic voltammetry. As an electrode material, MIL-100(Fe) is a sensing element that undergoes oxidation from Fe(ii)-MOF to Fe(iii)-MOF, and GO possesses high conductivity and a large surface area, which exhibits high absorbability. In the presence of DEX, Fe(iii) is reduced, which accelerates electron transfer at the electrode interface. Therefore, DEX can be quantitatively detected by analyzing the anodic current of MIL-100(Fe). When coupled with amperometric flow injection analysis, excellent performance can be obtained even when a low detection potential is applied (+0.10 V vs. Ag/AgCl). The concentration was linear in the range 0.10-5.0 μM and 0.010-5.0 mM with LOD of 0.030 μM based on 3(sd/slope). The modified electrode also exhibited a remarkably stable response under optimized conditions, and up to 55 injections can be used per electrode. The sensor exhibits high repeatability, reproducibility, and anti-interference properties when used for DEX detection. The effective determination of dexamethasone in real pharmaceutical and cosmetic samples demonstrated the feasibility of the electrochemical sensor, and the results were in good agreement with those obtained from the HPLC-DAD analysis. Acceptable percentage recoveries from the spiked pharmaceutical and cosmetic samples were obtained, ranging from 93-111% for this new method compared with 84-107% for the HPLC-DAD standard method.

Covalent integration of Fe-based metal–organic framework and triazine-containing covalent organic framework for enhanced adsorptive removal of antibiotics

Currently, the issue of antibiotic pollution in water bodies has been increasingly capturing people's attention. The use of high-performance adsorbents for removing antibiotics from water is an effective solution. In this study, NH2-MIL-53(Fe) and triazine-containing Tp-TTA were successfully combined to produce a novel MOF/COF composite named NMF/TT, capable of effectively adsorbing and removing antibiotics. Various characterization techniques were employed to determine the properties and morphology of NMF/TT, and the adsorption performance for four representative antibiotics (tetracycline, ciprofloxacin, ofloxacin, and norfloxacin) was investigated. Results indicated that NMF/TT-90 exhibited the optimal adsorption quantity, significantly enhancing the adsorption quantity compared to the pure components. The adsorption processes of the four antibiotics followed the pseudo-second-order kinetic model and Langmuir isotherm model. Among them, NMF/TT-90 demonstrated the highest adsorption quantity for tetracycline, with a maximum adsorption quantity of 118.48 mg g−1, and also exhibited an adsorption quantity of 55.93 mg g−1 for ciprofloxacin. Thermodynamic results confirmed the spontaneous nature of the adsorption processes for tetracycline and ciprofloxacin. NMF/TT-90 showed the strongest adsorption quantity for tetracycline at pH 7. Furthermore, the effects of adsorbent dosage, interfering ions, real water samples, and the regenerability of the adsorbent were investigated. The high adsorption quantity of the adsorbent is attributed to the π–π interactions, hydrogen bonding, and coordination between NMF/TT-90 and antibiotic molecules, as well as the possible defect effects during the composite formation process.

Integration of CuS@MIL-100 into cellulose hydrogel for synergistic seawater desalination and photocatalytic decontamination

A hydrogel solar evaporator is constructed by depositing photocatalysts into a cellulose matrix. The photocatalyst consists of copper sulfide (CuS) and Fe-based metal–organic framework (MIL-100(Fe)), with CuS particles loaded on MIL-100(Fe). By combining CuS@MIL-100 composites into cellulose hydrogel, the hydrogel solar evaporator can be acquired. The optimal evaporator exhibits an evaporation rate of 2.37 kg m-2h−1 at 1 kW m−2, with an evaporation efficiency of 94.4%. Moreover, the composite hydrogel can produce clean water from wastewater by coupling photothermal effects and photocatalytic degradation. The composite hydrogel exhibits a photocatalytic degradation efficiency of 97.3% for methylene blue (a typical dye contaminant) and 93.3% for tetracycline (a typical antibiotic). This work provides ideas for designing and manufacturing the next-generation of solar-powered water purification systems.

In-situ reconstruction of rock-like 3D hierarchical MIL-53(Fe) self-supporting electrode with oxygen vacancy induced ultra-long stable and efficient water oxidation

The exploitation of efficient, stable and cheap electrocatalyst for oxygen evolution reaction (OER) is very significant to the development of energy technology. In this study, Fe-based metal–organic frameworks (MIL-53(Fe)) self-supporting electrode with a 3D hierarchical open structure was developed through a semi-sacrificial strategy. The self-supporting electrode exhibits an excellent OER performance with an overpotential of 328 mV at 100 mA cm−2 in 1 M KOH, which is superior than that of IrO2 catalyst. Importantly, the optimized self-supporting electrode could operate at 100 mA cm−2 for 520 h without visible decrease in activity. It was also found that the structure of MIL-53(Fe) was in-situ self-reconstructed into oxyhydroxides during OER process. However, the 3D hierarchical open structure assembled with nano-microstructures kept well, which ensured the long-term stability of our self-supporting electrode for OER. Furthermore, density functional theory (DFT) calculations reveal that the FeOOH with rich oxygen vacancy transformed from MIL-53(Fe) plays a key role for the OER catalytic activity. And, the uninterrupted formation of oxygen vacancy during OER process ensures the continuous OER catalytic activity, which is the original source for the ultra-long stability of the self-supporting electrode toward OER. This work explores the way for the construction of efficient self-supporting oxygen electrodes based on MOFs.

Synthesis and characterization of MIL-101 (Fe) as efficient catalyst for tetracycline degradation by using NaBH4: Artificial neural network modeling

In this work, Fe-based metal organic framework (MIL-101 (Fe) MOF) was synthesized to use it as a catalyst for the catalytic degradation of tetracycline antibiotic with NaBH4. The synthesized MOF were characterized by Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy/Electron Dispersive X-ray and point of zero charge pH analysis. The effects of parameters such as contact time, pH, NaBH4 concentration and the amount of catalyst on the removal process were investigated and optimum parameters were determined. According to this, tetracycline removal efficiency was determined as 0.180 in terms of Ct/C0 at the end of 60-min contact time under determined optimum conditions for 60 ppm tetracycline solution. Moreover, the process was modeled with Artificial Neural Networks approach by using empirical results obtained from where process parameters were investigated. Finally, it was revealed with HPLC analysis that tetracycline was converted into different products as a result of applied process.

Superior Removal of Vanadium(V) from Simulated Groundwater with a Fe-Based Metal-Organic Framework Immobilized on Cotton Fibers.

A suitable adsorbent is essential in the process of removing hazardous vanadium(V) from actual groundwater. In this work, MIL-88A(Fe)/cotton (MC) was employed to eliminate V(V) from simulated vanadium-contaminated groundwater. The findings demonstrated that MC exhibited an exceptional performance in removing V(V), displaying a maximum adsorption capacity of 218.71 mg g-1. MC exhibits great promise as an adsorbent for V(V) elimination in an extensive pH range spanning 3 to 11. Even in the presence of high levels of competing ions such as Cl-, NO3-, and SO42-, MC demonstrated remarkable specificity in adsorbing V(V). The results of column experiments and co-occurring ions influence tests indicate that MC is a potential candidate for effectively treating actual vanadium-contaminated groundwater. The effluent could meet the vanadium content restriction of 50 μg L-1 required in China's drinking water sources. Regeneration of MC can be performed easily without experiencing significant capacity loss. The results obtained from this research indicate the promising potential of MC in mitigating vanadium pollution.

Exploring the potential of MIL-53(Fe) as a fluorescent probe for the highly selective and sensitive detection of anti-tuberculosis drug—Isoniazid

Ecosystem and human health can both be catastrophically harmed by overuse of anti-tuberculosis drug, isoniazid. Within this frame of reference, an Fe-based metal organic framework (MIL-53(Fe)) was developed via hydrothermal route to successfully recognise and detect, isoniazid antibiotic, using fluorescence sensing. The structural, morphological and other important property insights of MIL-53(Fe) were gained using various techniques like FT-IR, XRD, FE-SEM, BET, TGA and VSM. The developed fluorescence probe exhibited fluorescence enhancement with the incremental addition of isoniazid antibiotic, in the range of 0.1 to 7.0 µM. The limit of detection (LOD) value was found to be 0.25 µM under optimal sensing conditions. MIL-53(Fe) demonstrated high selectivity and specificity for the detection of isoniazid. In addition, the sensor displayed excellent performance in reproducibility, repeatability and real water studies.

Critical role of initial multi-phase microstructure on the phase transformations during hydrogenation in Fe–Mo alloy system

Given Fe is a low-cost earth-abundant element, there is a need to develop novel Fe-based metal hydrides. The conventional Fe-based hydrides consist of at least one metal with high hydrogen affinity. To synthesize novel low-affinity Fe-based hydrides, the high-pressure and high-temperature method is currently being used. The microstructure is known to influence the de-/hydrogenation processes in metal hydrides. However, in the context of low-affinity Fe-based hydrides, the role of the initial multi-phase microstructure is unknown, which is the objective of the current work. We investigate three as-cast Fe–Mo binary alloys: Fe0.33Mo0.67, Fe0.5Mo0.5, and Fe0.67Mo0.33. Firstly, we first explain in detail the formation mechanisms of the non-equilibrium initial as-cast microstructures caused by the sluggish diffusion of Mo. Subsequently, we present the phase transformations and microstructure evolution during the hydrogenation, depressurization, and aging of Fe–Mo alloys. We demonstrate that each phase in the initial microstructure act as an independent phase during hydrogenation.

Adsorption behavior and mechanism of modified Fe-based metal–organic framework for different kinds of arsenic pollutants

Arsenic in water environment can present significant threats to human health, and eliminating arsenic pollutants from wastewater is crucial. Based on our previously reported work, this study delved into the adsorption behavior and mechanism of different arsenic contaminants (p-ASA, ROX, As(V), and DMA) on the activated Fe-based metal–organic framework (activated MIL-88A). The results show that activated MIL-88A exhibits exceptional adsorption capabilities toward diverse arsenic pollutants. The adsorption process is endothermic, spontaneous, and viable, and chemical adsorption plays a leading role. The remarkable adsorption capacity of activated MIL-88A to various arsenic pollutants is primarily attributed to coordination, while hydrogen bonding also assumes a significant role in the elimination of p-ASA and ROX. Additionally, we investigated the impact of arsenic molecule shape and size, solution pH, and the existence of specific anions and dissolved organic matter (DOM) on the adsorption of different arsenic pollutants. This study can provide valuable insights for further exploring the selective adsorption of different kinds of arsenic species by Fe-based MOF materials and improving the adsorption efficiency of MOFs.

Highly durable platinum group metal-free catalyst fiber cathode MEAs for proton exchange membrane fuel cells

Fe-based platinum group metal (PGM)-free catalysts were incorporated into electrospun fiber mat or powder cathode membrane-electrode-assemblies (MEAs) with a Nafion 211 membrane and a Pt/C powder anode. Fabrication and characterization tests were performed on MEAs with: (1) a conventional powder cathode with a neat Nafion binder, (2) a fiber mat cathode with a Nafion/polyethylene oxide (PEO) binder, where PEO was extracted before MEA testing, (3) a powder cathode with a blended binder of Nafion and polyvinylidene fluoride (PVDF), and (4) a series of fiber mat cathodes with different Nafion/PVDF binder weight ratios. Cathode degradation occurred, with a loss in power output, in MEAs with a neat Nafion powder cathode or with a Nafion fiber cathode. In contrast, little or no power loss was observed for powder or fiber cathodes when the binder was a blend of Nafion and PVDF. The presence of hydrophobic PVDF drove water and electrogenerated peroxide out of the cathode, away from catalyst particles, which improved cathode durability, but PVDF also decreased the binder conductivity and slowed oxygen reduction kinetics, resulting in lower power densities. A 75:25 w:w Nafion:PVDF fiber cathode MEA was the best compromise for maximizing power and minimizing catalyst degradation. For such a cathode, with a PGM-free cathode catalyst loading of 3.0 mg cm−2, a power density of 88 mW cm−2 at 0.5 V, 80 °C, and 200 kPaabs pressure was maintained for 80 h of continuous operation.

Effect of mechanical milling on powder characteristics of Fe-based metal matrix composites reinforced with WC–Co and NbC particles

Effect of mechanical milling on powder characteristics of Fe-based metal matrix composites reinforced with WC–Co and NbC particles

Effects of Surface Oxidation on the Magnetic Properties of Fe-Based Amorphous Metal Powder Made by Atomization Methods

Effects of Surface Oxidation on the Magnetic Properties of Fe-Based Amorphous Metal Powder Made by Atomization Methods

Ni-modified FeOOH integrated electrode by self-source corrosion of nickel foam for high-efficiency electrochemical water oxidation

The construction and application of efficient iron oxyhydroxide (FeOOH) is still a challenge in the field of energy conversion. Here, a facile preparation method is developed by directly utilizing commercialized nickel foams (NF) as the nickel source and the supporting framework, as well as the ingenious use of etching effect originating from acidic medium in the process of iron salt hydrolysis. As a result, a Ni-modulated FeOOH integrated electrode (Ni-FeOOH/NF) is obtained. Unexpectedly, the implementation of our scheme effectively activates the catalytic intrinsic activity of FeOOH, successfully transforming the inert NF into an integrated electrode with high oxygen evolution reaction (OER) performance. Specifically, the Ni-FeOOH/NF exhibits the overpotential of 277 mV (@100 mA cm−2) and superior stability for OER. Additionally, the as-prepared Ni-FeOOH/NF electrode could also operate steadily for OER in alkaline adjusted saline water. Our research provides a new idea for the preparation of satisfactory Fe-based metal materials as OER electrocatalysts.

Polydopamine-cloaked Fe-based metal organic frameworks enable synergistic multidimensional treatment of osteosarcoma

One of the major challenges in effective cancer therapy arises because of the hypoxic microenvironment in the tumor. This compromises the efficacy of both chemo- and radiotherapy, and thus hinders patient outcomes. To solve this problem, we constructed polydopamine (PDA)-cloaked Fe-based metal organic frameworks (MOFs) loaded with d-arginine (d-Arg), glucose oxidase (GOX), and the chemotherapeutic drug tirapazamine (TPZ). These offer simultaneous multifaceted therapy combining chemodynamic therapy (CDT)/radiotherapy (RT)/starvation therapy (ST)/gas therapy (GT) and chemotherapy. The particles further can act as contrast agents in magnetic resonance imaging. GOX catalyses the conversion of endogenous glucose and O2 to hydrogen peroxide and gluconic acid, blocking the cells’ energy supply and providing ST. With the resultant acidification of the local environment, the breakdown of the MOF releases TPZ (for chemotherapy) and Fe3+, which reacts with H2O2 to produce reactive oxygen species and thus stimulates the conversion of d-Arg to NO for GT and RT sensitization. The PDA coating not only seals the pores and chelates Fe3+ to enhance the T1-weighted magnetic resonance imaging (MRI) properties, but also is used to graft folate bovine serum albumin (FA-BSA) and thereby target the tumor site. The combined administration of low doses of X-ray irradiation and nanoparticles reduces the side effects on healthy tissue and can prevent lung metastases in mice. This work highlights the synergistic treatment of osteosarcoma via ST/GT/CDT/RT/MRI/ chemotherapy using a PDA-cloaked MOF system.

Fe-Based Metal–Organic Frameworks with Ferroptosis Generation Ability for Remodeling Chemotherapy of Non-small Cell Lung Cancer

Fe-Based Metal–Organic Frameworks with Ferroptosis Generation Ability for Remodeling Chemotherapy of Non-small Cell Lung Cancer

Correlation of Magnetomechanical Coupling and Damping in Fe80Si9B11 Metallic Glass Ribbons.

Understanding the correlation between magnetomechanical coupling factors (k) and damping factors (Q-1) is a key pathway toward enhancing the magnetomechanical power conversion efficiency in laminated magnetoelectric (ME) composites by manipulating the magnetic and mechanical properties of Fe-based amorphous metals through engineering. The k and Q-1 factors of FeSiB amorphous ribbons annealed in air at different temperatures are investigated. It is found that k and Q-1 factors are affected by both magnetic and elastic properties. The magnetic and elastic properties are characterized in terms of the magnetomechanical power efficiency for low-temperature annealing. The k and Q-1 of FeSiB-based epoxied laminates with different stacking numbers show that a -3 dB bandwidth and Young's modulus are expressed in terms of the magnetomechanical power efficiency for high lamination stacking.

Enhanced catalytic oxidation of naproxen via activation of peroxymonosulfate by Fe-based metal–organic framework aerogels functionalized with Ag nanoparticles

In this study, Ag3PO4 and Fe-based metal–organic frameworks (MOFs)-functionalized three-dimensional (3D) porous gelatin aerogels (Ag/Fe@GMA) were fabricated and used as adsorbents and catalysts for the activation of peroxymonosulfate (PMS) for naproxen (NPX) removal from water. The morphology, crystallinity, surface functional groups, and surface chemical element compositions of the fabricated Ag/Fe@GMA was evaluated using various analytical techniques. Our results showed that as an adsorbent, Ag/Fe@GMA showed a 18.0 % higher NPX adsorption capacity compared with the pristine aerogels. This can be attributed to the well-embedded Ag3PO4 and MOFs, indicating a stronger interaction between functionalized aerogels and NPX. After adsorption, 99.9 % of total NPX removal was achieved within 15 min by activating PMS and effectively generating •OH and •SO4− in water. The PMS/Ag/Fe@GMA aerogel system also showed high removal performance for rhodamine B (99.5 %) and tetracycline (93.7 %). Moreover, the Ag/Fe@GMA aerogels showed excellent reusability to achieve 95.7 % NPX removal efficiency after six times of recycling. This study revealed that the Ag/Fe@GMA aerogels had good potential for PMS activation and NPX removal. In particular, as an alternative to powdery materials, 3D shape of Ag/Fe@GMA with excellent reusability facilitates its application in the treatment of water contaminated with organic contaminants.

Unveiling K-storage property of temperature-depended Fe-based metal organic terephthalate in KFSI-based electrolyte

Constructing suitable anode materials with high specific capacity, cyclic performance as well as low-cost have been mainly restricted by the large K+radius for inorganic counterparts in potassium-ion batteries recently. Herein, the potassium storage performance and reaction mechanism of temperature-depended organic iron terephthalate (FeC8H4O4) were comparatively investigated in difluoro-sulfonimide potassium (KFSI)-based ester and ether electrolytes. The as-prepared FeC8H4O4–250 with rough surface area and larger specific surface area, showed the best electrochemical performance than that of FeC8H4O4–150 and FeC8H4O4. It was disclosed that the potassium storage mechanism of FeC8H4O4–250 is based on the reversible enolation reaction of carbonyl and the conversion of Fe2+ into Fe nanoparticles, consequently resulting in high specific capacity. In addition, the results suggest that FeC8H4O4–250 exhibits better cycling stability in KFSI/DME electrolyte than in KFSI/EC+DEC, which is mainly because the salts and solvents in KFSI/EC+DEC contribute to the formation of a stable and robust SEI that inhibits the decomposition of the electrolyte. Our work is of significant to explore high-performance electrode materials for next-generation energy storage systems.

Fe-Based Metal Organic Frameworks (Fe-MOFs) for Bio-Related Applications.

Metal-organic frameworks (MOFs) are porous materials composed of metal ions and organic ligands. Due to their large surface area, easy modification, and good biocompatibility, MOFs are often used in bio-related fields. Fe-based metal-organic frameworks (Fe-MOFs), as important types of MOF, are favored by biomedical researchers for their advantages, such as low toxicity, good stability, high drug-loading capacity, and flexible structure. Fe-MOFs are diverse and widely used. Many new Fe-MOFs have appeared in recent years, with new modification methods and innovative design ideas, leading to the transformation of Fe-MOFs from single-mode therapy to multi-mode therapy. In this paper, the therapeutic principles, classification, characteristics, preparation methods, surface modification, and applications of Fe-MOFs in recent years are reviewed to understand the development trends and existing problems in Fe-MOFs, with the view to provide new ideas and directions for future research.