Iron Terephthalate Research Articles

Construction of a Three-Dimensional-Printed Immunosensing Platform Based on Smartphone Photothermal Signal Integration.

The combination of the photothermal effect and immunoassay serves as a potent tool for crafting cost-effective and user-friendly biosensing systems. To ensure efficient light-to-heat conversion, we integrated three-dimensional-printed (3D printed) technology to devise a novel design. This design functions as the structural support for both the cell phone and laser probe, as well as a means for sample handling. The main body features a three-way cavity structure, securing the test sample at a fixed position to maintain consistent light distance and angle, thereby minimizing testing errors. Card slot insert facilitates precise sample positioning to ensure the adequacy of receiving light. The sample holder's wide front and narrow back design enables the accommodation of fixed samples while providing a broad field of view, with intervals therein effectively preventing cascading heat. Our design employs MB@MOF235 (methylene blue adsorbed by iron terephthalate) as the photothermal reagent, successfully enabling the detection of α-fetoprotein (AFP). The detection range spans from 0.01 to 50 ng/mL, with a lower detection limit (LOD) of 0.032 pg/mL. The detection method, combining simplicity, portability, and visualization, offers a reliable reference for furthering precision medicine toward personalized medicine. Meanwhile, to verify the method's accuracy electrochemical testing was conducted to support the proof using the electro-oxidizing activity of MB.

Electrochemical sensing of acetaminophen in biofluids, pharmaceutical and environmental samples using cobalt hexacyanoferrate decorated iron terephthalate metal organic framework

Herein, a highly sensitive, cost-effective, and sustainable electrochemical sensor was developed for the selective sensing of acetaminophen (ACP) in actual samples using cobalt hexacyanoferrate (CHCF) incorporated iron terephthalate metal organic framework (FMF). The CHCF-FMF was sustainably synthesized and characterized using FTIR, XRD and SEM with EDX analysis. Using CHCF-FMF, a modified electrode was fabricated by drop-casting it over a glassy carbon, which on voltammetric investigations, revealed the presence of Co2+/3+ redox couple with a formal potential of 0.51 V. Further, the designed sensor was employed for the electrocatalytic oxidation of ACP, which showed a linear detection range from 0.05 to 7.37 mM with a sensitivity and detection limit of 100.64 µA/mM/cm2 and 13 µM, respectively. Furthermore, the developed CHCF-FMF/GCE sensing system is highly facile and robust, and it has demonstrated excellent stability, selectivity, repeatability, and good reproducibility. The superior performance was attributed to the in-situ formation of CHCF over FMF, which efficiently arranged them to augment the electrochemical and electrocatalytic properties. Besides, the sensor was employed to determine ACP in blood serum, commercial tablets, and environmental samples, which showed recovery ranges of 96.2% – 106.2%. This work provides a novel strategy for designing catalytically active sites at the molecular level, which opens a new avenue in fine-tuning MOFs for their applicability in medical diagnostics, point-of-care, industrial and environmental monitoring devices.

Iron terephthalate metal-organic framework (MOF‑235) modified with zinc as an efficient adsorbent for removal of tetracycline from aqueous solution

The study focused on synthesizing and modifying the MOF235-Zn composite to enhance its catalytic properties for removing tetracycline from water systems. Incorporating zinc into the MOF235 structure significantly improved its efficiency in tetracycline removal. Characterization methods such as SEM, mapping, EDS, and FTIR confirmed the successful synthesis and modification of the MOF235-Zn composite. The addition of zinc reduced the time needed for tetracycline removal and minimized the required amount of MOF235-Zn, even at room temperature. The study also investigated the impact of operational parameters on tetracycline adsorption and identified optimal conditions for tetracycline removal. Overall, the findings highlight the potential of the MOF235-Zn composite to effectively remove tetracycline, particularly under optimized operational conditions.

Construction of hybrid sulfur-doped MOF-235@g-C3N4 photocatalyst for the efficient removal of nicotine

Nicotine has inevitably been discharged into the environment either directly or as industrial effluent due to the widespread use of nicotine-based products worldwide. Its potential toxicity and irreversible impact on human health have made it a massive global issue. Presently, magnetic sulfur doped metal–organic framework-235 has been synthesized with iron terephthalate using the solvothermal approach and successfully applied as a photocatalyst for the elimination of nicotine. An array of techniques, including X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR) and scanning electron microscopy (SEM) were performed to evaluate the photocatalyst Ni-Mo.S2/MOF-235@g-C3N4, Mo.S2/MOF-235@g-C3N4, Ni.S2/MOF-235@g-C3N4, Ni-Mo.S2/MOF-235 nanocomposites. Studies also showed that Ni.S2 and Mo.S2 overlaid on the main precursor MOF-235@g-C3N4 produced a greater number of active sites and an appreciable rise in photocatalytic activity when exposed to visible light. A noticeable increase in absorbance was seen at the heterojunction of MOF-235@g-C3N4 and bimetallic sulfides (Ni.S2, Mo.S2) as compared to simple MOF-235. The experimental results proved that Ni-Mo.S2/MOF-235@g-C3N4 had the maximum level of catalytic activity while eliminating 98 % of the sample in 60 min. It was significantly greater than the corresponding value of pure Ni-Mo.S2@MOF-235 bimetallic sulfide photocatalyst. Additionally, first-order kinetics is evident according to kinetic studies, where R2 = 0.920. The enhancement of photocatalytic activity by Ni-Mo.S2/MOF-235@g-C3N4 was attributed to an increased surface area and porosity, enhanced absorption of light and a narrowing of band gap from 2.26 to 2.16 eV. A significant amount of stability and recyclability were also displayed by the composite during the course of three consecutive cycles of photocatalytic nicotine degradation. Only a minor change occurred during the fourth and fifth cycles, with a negligible weight loss. The experimental findings demonstrated that a sustainable rise in the quantity of photo generated electron/hole pairs (e−/h+) was likewise associated with enrichment in light absorption intensity. A photo-catalytic mechanism for accelerated nicotine photodegradation has actually been linked to the active species (O2•−) and (OH•). This study expands the application of MOF-235@g-C3N4, which exhibits tremendous capacity for environmental purification and serves as a reference when creating composites of g-C3N4 photocatalyst.

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.

Over 21.0% faradaic efficiency of ambient ammonia production: Photoelectrocatalytic activity of MOF-235

In recent years, the Haber-Bosh process's ammonia synthesis has shown a lot of energy consumption and significant CO2 emissions. In this sense, the photoelectrochemical production of NH3 via dinitrogen fixation has been showing a promising strategy. Thus, in this work, ammonia production under photoelectrocatalytic condition was carried out using the metal-organic iron terephthalate structure (MOF-235), obtained by a simple and low-cost process (solvothermal). The results indicated greater activity for the nitrogen reduction reaction (NRR) compared to the hydrogen reduction reaction (HRR), in addition to a high yield of NH3 0.716 µg h−1 cm−2 and Faradaic efficiency greater than 21.0% at - 0.2 V vs reversible hydrogen electrode in 0.1 mol L−1 Na2SO4 electrolyte. It is believed that the good results of MOF-235 during NRR are related to a high specific area of MOF, making available active sites of trinuclear-oxocentered iron in abundance. The material homogeneity in the electrode and the excellent light absorption were also decisive factors for the supply of high energy electrons necessary for ammonia production.

Nano-Porous Composites of Activated Carbon–Metal Organic Frameworks (Fe-BDC@AC) for Rapid Removal of Cr (VI): Synthesis, Adsorption, Mechanism, and Kinetics Studies

Metal–organic frameworks (MOFs) are a group of porous materials that display potential in the elimination of toxic industrial compounds (TICs) from polluted water streams. However, their applications have so far been held up by issues due to their physical nature and cost. In this study, activated carbon (AC) is modified with an Fe-based MOF, iron terephthalate (Fe-BDC). A facile and cost-effective impregnation method is used for enhanced removal from aqueous solutions. The new adsorbent is characterized by SEM, FTIR, PXRD, and BET. The composite displays excellent uptake of Cr (VI) when compared to un-impregnated AC with a maximum monolayer adsorption capacity of 100 mg·g−1. The experimental data shows a high correlation to the Langmuir adsorption model. The adsorption kinetic study reveals that the adsorption of Cr (VI) to Fe-BDC@AC obeys the pseudo-first-order equation. The composite shows high reusability after five cycles and high adsorption rates reaching equilibrium in just 50 min. Such properties make the nanocomposite promising for water decontamination on larger scales compared to powder-based alternatives, such as individual MOF crystals.

Iron-organic frameworks-derived iron oxide adsorbents for hydrogen sulfide removal at room temperature

We have reported iron-based MOFs by sonication of organic linkers with a freshly prepared iron hydroxide, which served as templates to yield iron oxide adsorbents after calcination. The PXRD analysis confirmed the presence of α-Fe2O3 and Na2SO4 in MOF-derived adsorbents. The XPS analysis confirmed the presence of both Fe2+ and Fe3+ species in all MOFs and derived iron oxide adsorbents. These adsorbents were studied for H2S removal in both dry and moist conditions at room temperature. The iron terephthalate MOF-derived iron oxide adsorbent showed the maximum adsorption capacity of 36.2 mg g−1 at moist conditions. The H2S removal process over iron oxide adsorbents was governed by the oxidation of H2S into sulfur and sulfates by Fe3+ and adsorbed oxygen. The spent adsorbent was regenerated by NH4OH to produce ammonium sulfate (liquid fertilizer), which is a novel approach to convert waste into value-added products.

Graphene oxide incorporated amino‐functionalized iron terephthalate composite as a heterogeneous Fenton‐like catalyst

AbstractAmino‐functionalized iron terephthalate metal–organic framework (NH2‐MIL‐88B) has been studied for its adsorption and catalytic properties due to its high surface area and unique topological architecture. Functionality of the material can be improved through surface modification to increase active sites for the targeted applications. In this study, graphene oxide (GO) was incorporated to the NH2‐MIL‐88B material to obtain composite with improved adsorption and catalytic properties. The results showed that GO/NH2‐MIL‐88B in dark (as GO/NH2‐MIL‐88B/Dark system) was capable to adsorb 28.1% of methylene blue (MB) in water, which is about twice the adsorption of MB by the NH2‐MIL‐88B material in dark (as NH2‐MIL‐88B/Dark system). Furthermore, with the presence of hydrogen peroxide (H2O2), the GO/NH2‐MIL‐88B composite in dark condition (as GO/NH2‐MIL‐88B/H2O2/Dark) and the GO/NH2‐MIL‐88B composite under ultraviolet‐A (UV‐A) irradiation (as GO/NH2‐MIL‐88B/H2O2/UV‐A) have shown promising Fenton‐like behavior, which have removed 72.2% and 92.3% of MB in water, respectively. The removal of MB was well fitted to the Langmuir–Hinshelwood pseudo‐first order kinetics model with the reaction rate constant, k1 = 0.0221 min−1 and k1 = 0.0426 min−1 for GO/NH2‐MIL‐88B/H2O2/Dark and GO/NH2‐MIL‐88B/H2O2/UV‐A system, respectively. This study implies that the GO/NH2‐MIL‐88B composite can be a good catalyst for the heterogeneous Fenton‐like degradation of cationic pollutants in water.

Enhanced Photocatalytic Degradation of MB Under Visible Light Using the Modified MIL-53(Fe)

In this report, we focus on the modification of iron terephthalate metal–organic framework (MIL-53(Fe)) by soaking in H2O2 solution and its mechanism. The structure of MIL-53(Fe) before and after the modification were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and N2 adsorption–desorption isotherms. The XRD results showed that the material structure changed to amorphous phases and the photocatalytic efficiency was improved after modified by H2O2. The MIL-53 (Fe, H2O2) nanoparticles about 100–300 nm in size was successfully prepared and confirmed by SEM images. In term of UV–Vis DRS results, the absorption spectrum of modified MIL-53(Fe) shifted to higher wavelength and its band gap energy is estimated about 2.2 eV, which is significantly lower than the bandgap value of the conventional material. The impact of the modification on the photocatalytic efficiency was investigated by methylene blue (MB) degradation experiments and photoluminescence (PL) spectroscopy. MB was completely decomposed within 30 min by modified MIL-53(Fe) under optimal conditions. The reaction parameters that affect MB degradation by the as-prepared catalyst were also investigated, including the pH solution, catalyst and H2O2 dosage.

Iron terephthalate metal–organic framework (MOF-235) as an efficient adsorbent for removal of toluidine blue dye from aqueous solution using Box–Behnken design as multivariate optimization approach

In this work, iron terephthalate metal–organic framework (MOF-235) as an efficient adsorbent has been synthesized and employed for toluidine blue (TB) removal in a batch system. The adsorbent was characterized by Fourier-transform infrared, scanning electron microscopy, and powder X-ray diffraction. The effects of operational parameters including pH, initial dye concentration (Cd), and the adsorbent dosage (m) on the TB adsorption were studied. A Box–Behnken design (BBD) was applied to identify the effective factors on the removal efficiency (R%) of toluidine blue. The optimal conditions were as follows: m = 0.02 g, Cd = 100 mg L−1, and pH = 4.5. The equilibrium adsorption isotherms and kinetic models were also studied. Since the results of the Langmuir model fitted well to all the experimental data (R2 = 0.9972), the maximum monolayer adsorption of TB was 180.4 mg g−1. Furthermore, the pseudo-second-order model describes well the process. Iron terephthalate metal–organic framework (MOF-235) shows a great potential to remove TB from aqueous solution.

Heterogeneous UV/Fenton-Like Degradation of Methyl Orange Using Iron Terephthalate MIL-53 Catalyst

The synthesis and degradation of methyl orange (MO) in an ultraviolet-assisted heterogeneous Fenton-like process via the iron terephthalate (MIL-53) catalyst are demonstrated. MIL-53 material was characterized by means of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectra (DR-UV-Vis), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen adsorption/desorption isotherms. It was found that the obtained material shares an identical pattern of the MIL-53 structure with high crystallinity and also demonstrates the mesoporous phase with a pore diameter of around 4.2 nm and specific surface area, SBET, of 88.2 m2·g−1. MIL-53 with UV irradiation exhibits high catalytic activity for MO degradation by hydrogen peroxide. The factors affecting the efficiency of MO decomposition including pH of the solution, H2O2 concentration, catalyst dosage, initial MO concentration, and reaction temperature were addressed. The present catalyst is stable after four recycles with slight catalytic activity loss which makes it a potential candidate for environmental restoration.

Hydrothermal Synthesis of MIL-53 Catalyst for Liquid Phase Oxidation of Phenol Fenolün Sıvı Faz Oksidasyonu için Mil-53 Katalizörünün Hidrotermal Sentezi

For the removal of toxic organic phenol pollutants, to find a new alternative oxidation catalyst has been an important
 topic for a long time. Iron terephthalate (MIL-53) is an efficient catalyst for oxidation processes with high porosity and
 high surface area. In this study, MIL-53 was used for the oxidation of phenol. The catalyst was synthesized by hydrothermal
 method at 150°C for 2 h. It was structurally characterized by FT-IR and p-XRD. Thermal properties were also examined. The
 surface area was found as 152 m2
 /g with micropore areas. The liquid phase oxidation of phenol by hydrogen peroxide was
 performed on MIL-53. The reaction time, reaction temperature, catalyst amount and oxidant amount were also investigated.
 The phenol was removed with 91% conversion for 3 hours at 80°C. MIL-53 was enhanced as an alternative catalyst for liquid
 phase oxidation of phenol with high efficiency, selectivity, and conversion.

Electrostatic Purification of Mixed-Phase Metal–Organic Framework Nanoparticles

Although macroscopic metal–organic framework (MOF) single crystals have been routinely synthesized, undesired impurity phases are sometimes obtained in MOF nanoparticle (NP) syntheses, where purification remains challenging. Herein we report an electrostatic adsorption strategy to separate mixed phases of MOF NPs on the basis of their metal cluster-dependent surface charge differences. As a proof of concept, two groups of mixed-phase MOF NPs were synthesized and subsequently separated on the basis of their different Coulombic attraction to negatively charged magnetic beads (MBs). Different frameworks form on the basis of the conditions used. In the first group, a combination of three possible iron–terephthalate frameworks were evaluated: MIL-53, MIL-88B, and MIL-101 (MIL = Material Institute Lavoisier). In the second group, two zirconium–terephthalate frameworks were separated: MIL-140A and UiO-66 (UiO = University of Oslo). MIL-53 and MIL-140A are not positively charged and do not adsorb onto the MBs. Th...

Iron-Terephthalate Coordination Network Thin Films Through In-Situ Atomic/Molecular Layer Deposition

Iron terephthalate coordination network thin films can be fabricated using the state-of-the-art gas-phase atomic/molecular layer deposition (ALD/MLD) technique in a highly controlled manner. Iron is an Earth-abundant and nonhazardous transition metal, and with its rich variety of potential applications an interesting metal constituent for the inorganic-organic coordination network films. Our work underlines the role of the metal precursor used when aiming at in-situ ALD/MLD growth of crystalline inorganic-organic thin films. We obtain crystalline iron terephthalate films when FeCl3 is employed as the iron source whereas depositions based on the bulkier Fe(acac)3 precursor yield amorphous films. The chemical composition and structure of the films are investigated with GIXRD, XRR, FTIR and XPS.

A simple modified electrode based on MIL-53(Fe) for the highly sensitive detection of hydrogen peroxide and nitrite

A modified matrix of an iron terephthalate metal–organic framework (MIL-53(Fe)), as a simple and efficient electroactive material for use as an electrochemical biosensor, was investigated.

From metal–organic frameworks to magnetic nanostructured porous carbon composites: towards highly efficient dye removal and degradation

A magnetic nanostructured porous carbon material (γ-Fe2O3/C) was easily synthesized using a microwave-enhanced high-temperature ionothermal method with an iron terephthalate metal–organic framework-MIL-53(Fe), as a template.

Graphene Hybridized Photoactive Iron Terephthalate with Enhanced Photocatalytic Activity for the Degradation of Rhodamine B under Visible Light

In this study, we report the design and fabrication of a series of visible-light-responsive photocatalysts based on one-dimensional iron terephthalate (MIL-53(Fe)) microrods hybridized with graphene (GR) and experimentally demonstrate their remarkably improved visible-light-induced photocatalytic activity. During the solvothermal process, the reduction of graphene oxide (GO) is accompanied by the MIL-53(Fe) crystallization, which endows them with effective interfacial contact, thus facilitating the transfer of photogenerated charge to lower the recombination rate of excited carriers. The GR/MIL-53(Fe)-H2O2 systems exhibit significantly higher photocatalytic activity toward degrading Rhodamine B (RhB) than that of bare MIL-53(Fe)-H2O2 under visible light irradiation. The introduced H2O2 induces photosynergistic generation of more amounts of hydroxyl radicals to contribute to the improved photocatalytic activity. This work could open a new way for the exploration and utilization of metal–organic framework (MOF)-based crystalline materials for light harvesting.

A simple solvothermal process for fabrication of a metal-organic framework with an iron oxide enclosure for the determination of organophosphorus pesticides in biological samples

An active magnetic metal-organic framework (MOF) hybrid material was prepared using a novel in situ solvothermal method in the presence of magnetite (Fe3O4) particles, that holds much promise for large-scale synthesis. MIL-101(Fe), an iron terephthalate with pore structure and high resistance to water and common solvents, was functionalized as a model with superparamagnetic qualities, using Fe3O4. The electrostatic interaction between Fe3O4 and metal ions was thereby used to chemically stabilize magnetic nanoparticles, and thus MOF crystals were uniformly enclosed by Fe3O4 to form a homogeneous magnetic product identified as a Fe3O4/MIL-101 composite. This hybrid material with magnetic susceptibility but with the lowest possible loading amount of Fe3O4 was examined, and its potential application for magnetic solid-phase extraction of six organophosphorus pesticides (OPPs) from human hair and urine samples, followed by gas chromatography analysis, was assessed. The main effect parameters including solution ionic strength, desorption solvent, extraction time and desorption time were investigated in sequence. Under optimized conditions, this method showed low detection limits (0.21–2.28ng/mL), wide linearity, and good precision (1.8–8.7% for intra-day, 2.9–9.4% for inter-day). The matrix interference produced by hair or urine could be effectively eliminated using this method, and satisfactory recoveries of the spiked samples were 76.8–94.5% and 74.9–92.1%, respectively, indicating that the Fe3O4/MIL-101 sorbents are feasible for the analysis of trace analytes from biological samples.

Iron terephthalate metal–organic framework: Revealing the effective activation of hydrogen peroxide for the degradation of organic dye under visible light irradiation

Metal–organic frameworks (MOFs), a new class of porous crystalline materials, have attracted great interest as a promising candidate for sustainable energy and environmental remediation. In this study, we demonstrate that an iron terephthalate metal–organic framework MIL-53(Fe) synthesized by a facile solvothermal reaction was capable of activating hydrogen peroxide (H2O2) to achieve high efficiency in photocatalytic process. It could completely decompose the 10mgL−1 Rhodamine B (RhB) in the presence of a certain amount of H2O2 under visible light irradiation within 50min. The catalytic activities were found to be strongly affected by the various operating parameters, such as solution pH, initial dye concentration, and H2O2 dosage. The activation effects of MIL-53(Fe) were investigated through the detection of hydroxyl radicals (OH) and transient photocurrent responses, which revealed that the H2O2 behaved in two ways during the catalytic process: (i) it could be catalytically decomposed by MIL(Fe)-53 to produce OH radicals through the Fenton-like reaction; (ii) it could capture the photogenerated electrons in the conduction band of excited MIL-53(Fe) to form OH radicals under visible light irradiation. The ability of such iron-based MOFs to activate H2O2 may enable rational design of advanced MOF-based catalysts for environmental remediation.