Reduction Of Fe3 Research Articles

Green synthesis of magnetite nanoparticles (Fe3O4 NPs) using Acacia concinna fruit extract and their antibacterial activity

AbstractThis paper describes green, simple, and efficient method for the synthesis of magnetite nanoparticles (Fe3O4 NPs) using Acacia concinna fruit extract for the first time. A. concinna fruit extract is used as reducing and stabilizing agent. Reduction of Fe3+ ions by A. concinna fruit extract is examined by UV‐visible absorption spectra (UV‐Vis‐NIR). To recognize the functional group responsible for Fe3O4, the NPs are characterized by Fourier transform infra‐red spectroscopy (FTIR). The structural analysis of Fe3O4 NPs is done by X‐ray diffraction (XRD) which confirms cubic spinel structure and the average crystallite size of obtained NPs is found to be 28 nm. The morphological studies of Fe3O4 NPs are done by scanning electron microscope (SEM) which depicts the quasi‐spherical morphology. The green synthesized Fe3O4 NPs shows distinctive antibacterial activities against gram‐negative E. coli and Pseudomonas aeruginosa microorganism which confirms its potential in biomedical applications.

Synthetically Produced Isocubanite as an Anode Material for Sodium-Ion Batteries: Understanding the Reaction Mechanism During Sodium Uptake and Release.

Bulk isocubanite (CuFe2S3) was synthesized via a multistep high-temperature synthesis and was investigated as an anode material for sodium-ion batteries. CuFe2S3 exhibits an excellent electrochemical performance with a capacity retention of 422 mA h g-1 for more than 1000 cycles at a current rate of 0.5 A g-1 (0.85 C). The complex reaction mechanism of the first cycle was investigated via PXRD and X-ray absorption spectroscopy. At the early stages of Na uptake, CuFe2S3 is converted to form crystalline CuFeS2 and nanocrystalline NaFe1.5S2 simultaneously. By increasing the Na content, Cu+ is reduced to nanocrystalline Cu, followed by the reduction of Fe2+ to amorphous Fe0 while reflections of nanocrystalline Na2S appear. During charging up to -5 Na/f.u., the intermediate NaFe1.5S2 appears again, which transforms in the last step of charging to a new unknown phase. This unknown phase together with NaFe1.5S2 plays a key role in the mechanism for the following cycles, evidenced by the PXRD investigation of the second cycle. Even after 400 cycles, the occurrence of nanocrystalline phases made it possible to gain insights into the alteration of the mechanism, which shows that CuxS phases play an important role in the region of constant specific capacity.

A Self-Driven Bioreactor Based on Bacterium-Metal-Organic Framework Biohybrids for Boosting Chemotherapy via Cyclic Lactate Catabolism.

The excessive lactate in the tumor microenvironment always leads to poor therapeutic outcomes of chemotherapy. In this study, a self-driven bioreactor (defined as SO@MDH, where SO is Shewanella oneidensis MR-1 and MDH is MIL-101 metal-organic framework nanoparticles/doxorubicin/hyaluronic acid) is rationally constructed via the integration of doxorubicin (DOX)-loaded metal-organic framework (MOF) MIL-101 nanoparticles with SO to sensitize chemotherapy. Owing to the intrinsic tumor tropism and electron-driven respiration of SO, the biohybrid SO@MDH could actively target and colonize hypoxic and eutrophic tumor regions and anaerobically metabolize lactate accompanied by the transfer of electrons to Fe3+, which is the key component of the MIL-101 nanoparticles. As a result, the intratumoral lactate would undergo continuous catabolism coupled with the reduction of Fe3+ to Fe2+ and the subsequent degradation of MIL-101 frameworks, leading to an expeditious drug release for effective chemotherapy. Meanwhile, the generated Fe2+ will be promptly oxidized by the abundant hydrogen peroxide in the tumor microenvironment to reproduce Fe3+, which is, in turn, beneficial to circularly catabolize lactate and boost chemotherapy. More importantly, the consumption of intratumoral lactic acid could significantly inhibit the expression of multidrug resistance-related ABCB1 protein (also named P-glycoprotein (P-gp)) for conquering drug-resistant tumors. SO@MDH demonstrated here holds high tumor specificity and promising chemotherapeutic efficacy for suppressing tumor growth and overcoming multidrug resistance, confirming its potential prospects in cancer therapy.

Complementary operando insights into the activation of multicomponent selective propylene oxidation catalysts

Two Bi–Mo–Co–Fe–O catalysts were synthesized by flame spray pyrolysis and tested for their catalytic performance in selective oxidation of propylene to acrolein. Pronounced structural changes during temperature–programmed oxidation and reaction were observed by operando X–ray absorption spectroscopy, X–ray diffraction, Raman spectroscopy, and thermogravimetric analysis. During oxidative treatment, mainly binary oxide phases (α–Bi2Mo3O12, β–CoMoO4, Fe2(MoO4)3) were observed, but single (MoO3) or ternary (Bi3(FeO4)(MoO4)2) oxides also formed depending on the relative elemental catalyst composition. During propylene oxidation, the reduction of Fe3+ to Fe2+ led to a strong rise in activity and induced further phase transformations. MoO3 was found to be unselective towards acrolein but was essential in binding other single oxides. The formation of β–Co0.7Fe0.3MoO4 and Bi3(FeO4)(MoO4)2 as well as their synergistic interplay with α–Bi2Mo3O12 are key factors for high performance. The combination of complementary operando methods was crucial to reveal new structure–activity/selectivity correlations, therefore bridging the knowledge gap between simplified model systems and complex applied catalysts.

A DFT investigation into the effects of As-doping on the electronic structure and electrochemical activity of pyrite (FeS2)

Pyrite (FeS2) is a semiconductor mineral with electronic structural properties that are heavily influenced by trace elements in its composition. It has been demonstrated experimentally that the reduction of Fe3+ ions is significantly enhanced in the presence of trace arsenic (As) atoms in FeS2. Using density functional theory calculations, we compare the geometric and electronic structural properties of pure and As-doped (110) pyrite surfaces. The interaction of the Fe3+ ion, a common oxidant of sulfides in acidic solution and acid mine drainage, with the aforementioned surfaces is thoroughly investigated. The findings reveal that the addition of an As atom alters the electronic structure of pyrite and decreases its band gap. The adsorption energy of the Fe3+ ion on As-doped pyrite is greater than that on pure pyrite. The calculated Gibbs free energy changes show that the reduction of Fe3+ to Fe2+ ion on the As-modified surface is thermodynamically more favorable than on pure pyrite.

A Z-scheme system constructed from WO3 modified TiO2 doped with Cr and Sb for visible light-driven overall water splitting

An artificial Z-scheme system using powder photocatalysts and a reversible redox mediator for the overall water splitting has been attracting attention for producing renewable H2 using solar energy. For the efficient use of this system, the development of efficient photocatalysts utilizing longer wavelength light is essential. TiO2 doped with Cr and Sb (TiO2:Cr/Sb) is one of the visible-light-active photocatalysts which has a bandgap of ca. 2.2 eV and absorbs light up to near 600 nm. However, TiO2:Cr/Sb powder in the Fe3+/Fe2+ reversible redox mediator showed negligible activity under visible light irradiation (λ > 460 nm). In this work, it was found that the photocatalytic performance for O2 evolution over TiO2:Cr/Sb modified with WO3 (WO3-TiO2:Cr/Sb) using the Fe3+/Fe2+ mediator was more than 15 times higher than that without modification. The apparent quantum efficiency of WO3-TiO2:Cr/Sb was estimated to be ca. 0.8% at 510 nm. The overall water splitting activity of Z-scheme water splitting (H2/O2 = 2), in combination with Ru/SrTiO3:Rh, was 9 times improved by the WO3 modification compared to that without modification. From the results of photoelectrochemical measurements, it was surmised that the loaded WO3 on the surface of TiO2:Cr/Sb may promote both reduction of Fe3+ to Fe2+ and oxidation of H2O to O2.

Chemical looping co-conversion of CH4 and CO2 using Fe2O3/Al2O3 pellets as both oxygen carrier and catalyst in a fluidized bed reactor

Chemical looping reforming of CH4 (CH4-CLR) is a safe and efficient CH4 upgrading technology for syngas production. The Fe2O3-based oxygen carriers (OCs) possess a higher potential for CH4-CLR among so many transition metal oxides as high syngas selectivity can be obtained from partial CH4 oxidation by OCs with the step-by-step reduction of Fe3+/Fe2+ to Fe0. However, the impurity CO2 in CH4-source feed gas, when using Fe2O3-based OCs, often causes the inhibition of reaction between CH4 and OCs resulting in no partial CH4 oxidation to syngas. The present work has employed the Fe2O3/Al2O3 pellets as OCs with introducing the fully reduced same pellets as a catalyst in a bubbling fluidized-bed reactor to eliminate the inhibition effect of CO2 during CH4-CLR. It has been demonstrated that the Fe species with low valent, e.g., Fe0, in the catalyst can effectively catalyze the dry CH4 reforming. Thus, the CO2 has been consumed before contacting with Fe2O3-based OCs and the inhibition effect of CO2 has been eliminated. Meanwhile, both CO2 and CH4 can be converted to syngas in the reducer leading to an opportunity for CO2 utilization. With the help of the catalyst of reduced OCs, not only the CO2 in the feed gas but also that formed from full CH4 oxidation by Fe2O3/Al2O3 at the early CH4 reforming stage is converted into syngas of CO and H2. Semi-continuous cyclic CH4-CLR test has demonstrated the good stability of both Fe2O3/Al2O3 OC and counterpart catalyst, which suggests the potential of such OC/catalyst pair in practical applications.

The Electrochemical Reduction Mechanism of ZnFe2O4 in NaCl-CaCl2 Melts

The electrochemical reduction process of ZnFe2O4 in NaCl-CaCl2 melts was studied. Thermodynamic analysis shows that the reduction process of ZnFe2O4 is carried out in multiple steps, and it is difficult to reduce Fe3+ to Fe in one step. Electrochemical tests revealed that the reduction process of ZnFe2O4 includes three steps: First, Fe3+ is reduced to Fe in two steps, then Zn2+ is reduced to Zn in one step. The reduction of Fe3+ on the Mo electrode is a reversible process controlled by diffusion, while the reduction of Zn2+ is an irreversible process controlled by diffusion. The influence of electrolysis voltage and temperature on the process of electric deoxidation has also been studied. It is indicated that properly increasing the temperature is conducive to the diffusion of oxygen ions, thereby increasing the deoxidation rate. With the gradual increase of voltage, the reduction process of ZnFe2O4 is ZnFe2O4 → FeO + ZnO → Fe + ZnO → Fe + Zn.

ZIF-L Derived Bimetallic N-Doped Porous Carbon-Prussian Blue Composite as Efficient Catechol Electrochemical Sensor

The development of effective and accurate catechol (CC) electrochemical sensors is critical for environment and life health perspectives. A facile pyrolysis of 2D bimetallic (Zn/Co) zeolitic imidazolate framework (Zn/Co-ZIF-L) was employed to prepare Zn and Co nanoparticles encapsulated in N-doped porous carbon (Zn/Co@NPC). Prussian blue (PB) was synthesized in situ via the co-precipitation of ferricyanide ([Fe(CN)6]3−) and iron (II) ion originated from the reduction of Fe3+ by Zn/Co@NPC and then served as the main active substance of CC detection. The morphology and composition of the final composite Zn/Co@NPC-PB were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The Zn/Co@NPC-PB modified glass carbon electrode (GCE) exhibits two concentration linear ranges of 4.13 μM − 1.08 mM (R2 = 0.999) and 1.08 mM−11.82 mM (R2 = 0.999) for CC electrochemical detection with a limit of detection 1.05 μM (S/N = 3). At the same time, the Zn/Co@NPC-PB/GCE shows great selectivity to electrochemical oxidation behavior of CC in presence of 20 folds dihydroxybenzene interferents such as hydroquinone and resorcinol. Furthermore, it showed a long-term stability and near 100% recovery for the detection of a real sample in Yellow River water.

The role of humic acid in Fenton reaction for the removal of aliphatic fraction of total petroleum hydrocarbons (diesel range) in soil

This study investigated the role of humic acid in Fenton reaction for the total petroleum hydrocarbons (TPH) (diesel) in soil. Batch reactions were conducted at varying humic acid dosages and pH. For the lowest molecular weight diesel contaminants, a humic acid dosage of 10 mg/l produced the favourable effect of reducing Fe3+ to Fe2+ which continued for higher humic acid dosages of 50, 100 and 150 mg/l. Conversely, for higher molecular weight diesel contaminants, the negative effect of hydroxyl radicals consumption by the humic acid was more significant than its reduction of Fe3+ to Fe2+. The positive role of humic acid on Fenton reaction increased with increasing humic acid dosage for the overall TPH, with an optimum dosage of 150 mg/l. At higher pH, the removal efficiencies increased or reduced depending on the molecular weight of TPH. The power law and pseudo-first-order kinetic models fitted the experimental kinetic data well.

Analysis of spectrum-activity relationship among antioxidant parts of Lycii Fructus using three different chemometrics methods

The chemical components of Lycii Fructus were analyzed by liquid chromatography( LC) and mass spectrometry( MS for the establishment of spectrum-activity relationship,on the basis of which its antioxidant active ingredients were determined. In this experiment,Lycii Fructus was extracted with different solvents and then separated into 80 samples by macroporous adsorption resin and reversed-phase chromatography,respectively. The antioxidant components were enriched into 11 samples and their scavenging abilities against DPPH free radical and ferric ion reducing antioxidant power( FRAP) were significantly stronger than those before the treatment( P<0. 05). The spectrum-activity relationship regarding the antioxidant activity in vitro of Lycii Fructus was established by Pearson correlation analysis,orthogonal partial least squares( OPLS) and elastic net regression. Six chromatographic peaks greatly contributing to the antioxidant activity in vitro of Lycii Fructus were identified as rutin( P6),quercetin( P35),scopoletin( P14),N-cis-feruloyl-4-O-β-D-glucopyranosyl-tyramine or N-( 4-O-β-D-glucopyranosyl-trans-feruloyl)-tyramine( P8), ferulic acid( P13) and1,3,5-dihydroxy-2-isoprenyl-3-xanthone( P23). The active components associated with free radical scavenging were rutin and quercetin both belonging to flavonoids. The reduction of Fe3+was based on phenylpropanoids such as ferulic acid,scopoletin,xanthone and phenolic amides. These results indicated that the antioxidant activity of Lycii Fructus was ascribed to the synergistic action of different products through different ways. Besides,the data analysis model should be chosen carefully for the establishment of spectrum-activity relationship,thus ensuring the reliability of results.

Photometric Screening of Tetrabromobisphenol A in Resin Using Iron(III) Nitrate/Hexacyanoferrate(III) Mixture as a Colorimetric Reagent.

This study aims to provide a simple way to identify the possibility of tetrabromobisphenol A (TBBPA) present in polymers without the need for complicated separation with expensive equipment. Since the presence of phenolic hydroxyl groups is known to be identifiable by the reduction of Fe3+ to Fe2+ in a ferric coloring reagent, the possibility of TBBPA being present in a polymer can be screened by a photometric measurement. A mixed solution of iron(III) nitrate and potassium hexacyanide(III) acid was used as a ferric coloring reagent. With this method, the concentration of TBBPA can be estimated from the photometric absorbance corresponding to the depth of the blue color produced by reduction of the ferric reagent in the presence of Fe(NO3)3. The limit of detection (LOD) was determined to be approximately 2 mg/kg using the Student's t-test (99% confidence), and a reproducibility of approximately 3% was determined by the relative standard deviation (RSD) from measurements of calibration samples (n = 7). Furthermore, TBBPA in actual polymer samples was screened without the need for any complex processing steps. Because this colorimetric method measures TBBPA by detecting phenolic groups, it may overestimate the TBBPA concentration in the presence of other similar phenolic substances. Nonetheless, this simple colorimetric method should help to quickly identify the presence of TBBPA in various polymers.

Assessment of chemically and enzymatically modified chitosan with eugenol as a coating for viscose functionalization for potential medical use

The present work deals with the preparation of chemically and enzymatically eugenol-modified chitosan and its application as a green coating on viscose for the potential production of medical textiles. The elemental composition of chemically and enzymatically eugenol-modified chitosan was determined by attenuated total reflection Fourier transform infrared (ATR FT-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. Moreover, potentiometric titration was used to estimate the number of accessible amino groups. The chitosan–eugenol formulation possesses a high antioxidant capacity level, as shown by the high content of phenolic compounds analyzed by the following methods: (a) Folin–Ciocalteu; (b) reduction of Fe3+ ions; and (c) α, α-diphenyl-β-picrylhydrazyl (DPPH•). Viscose coated with chitosan–eugenol formulations was evaluated by ATR FT-IR spectroscopy and Acid Orange VII spectrophotometric methods, the results of which demonstrated the successful deposition of these formulations on the fibers. Scanning electron microscopy showed the presence of the functional coating on the viscose. Finally, antimicrobial testing was performed to determine inhibition of selected pathogenic micro-organisms using the ASTM E 2149-01 standard. The antioxidant activity of the functionalized viscose was investigated spectrophotometrically by the DPPH• method. It was found that the coatings of eugenol-modified chitosan impart antimicrobial activity to the viscose against Gram-positive and Gram-negative bacteria as well as fungi, and cause inhibition of free radicals by introducing an antioxidant character. The chemical and enzymatic modification of chitosan offers many opportunities for the incorporation of many natural active ingredients into the chitosan system, which provides a good basis for further work related to the functionalization of chitosan for sanitary and medical use.

High Figure of Merit Magneto‐Optical Ce‐ and Bi‐Substituted Terbium Iron Garnet Films Integrated on Si

AbstractFilms of polycrystalline terbium iron garnet (TbIG), cerium‐substituted TbIG (CeTbIG), and bismuth‐substituted TbIG (BiTbIG) are grown on Si substrates by pulsed laser deposition. The films grow under tensile strain due to thermal mismatch with the Si substrate, resulting in a dominant magnetoelastic anisotropy which, combined with shape anisotropy, leads to in‐plane magnetization. TbIG has a compensation temperature of 253 K which is reduced by substitution of Ce and Bi. The Faraday rotation at 1550 nm of the TbIG, Ce0.36TbIG, and Bi0.03TbIG films is 5400 ± 600° cm−1, 4500 ± 100° cm–1, and 6200 ± 300° cm−1, respectively, while Ce0.36TbIG and Bi0.03TbIG exhibit lower optical absorption than TbIG, attributed to a reduction in Fe2+ and Tb4+ absorption pathways. The high Faraday rotation of the films, and in particular the high magneto‐optical figure of merit of the Bi0.03TbIG of 720° dB−1 at 1550 nm, make these polycrystalline films valuable for applications in integrated photonics.

Visible-Light Enhanced Catalytic Wet Peroxide Oxidation of Natural Organic Matter in the Presence of Al/Fe-Pillared Clay

An Al/Fe-pillared clay catalyst (Al/Fe-PILC) prepared from low cost technical-grade reagents has been investigated in the photocatalytic Wet Peroxide Oxidation (photo-CWPO) of dissolved Natural Organic Matter (NOM) under circumneutral pH. The successful pillaring of the layered clay material was confirmed by X-ray diffraction (XRD), N2 adsorption at −196 °C, cation exchange capacity (CEC) and simultaneous thermal analysis (TGA/DSC). High levels of mineralization of the dissolved organic carbon and color removal of a synthetic NOM surrogate solution were achieved even under natural lab’s lighting and ambient temperature and pressure, whereas the absence of radiation (in dark) was found to strongly affect the performance of the degradation. The photo-CWPO of NOM activated by the Al/Fe-PILC clay catalyst under visible light irradiation (LED lamp, 450 and 550 nm peaks) displayed a DOC mineralization of 72% and color removal of 73% in just 210 min of irradiation at neutral pH, whereas both responses decayed under ultraviolet lightning (λ: 365 nm) to 41% and 58%, respectively. This behavior is ascribed to formation of triplet states of natural organic matter (3NOM*) by absorption of visible light, which seems to synergistically improve the rate-determining step of the heterogeneous Fenton process, namely reduction of Fe3+ into Fe2+ on the surface of the clay catalyst. Interestingly, experiments performed at neutral and pH 3.0 showed very similar efficiencies under visible light irradiation; these findings may really facilitate the application of the photo-CWPO process to assist conventional drinking water treatment plants in the removal of NOM before the typical disinfection by chlorine to produce safer drinking water.

Molecular Hydrogen: Redox Reactions and Possible Biological Interactions

Molecular hydrogen (H2), either as a gas or as hydrogen-rich water (HRW), is suggested to be a useful treatment for a range of human diseases and also to improve agricultural output. It is often posited that H2 accomplishes its biological action, in part, through its antioxidant effects, including reacting with hydroxyl radicals (OH˙) and peroxynitrite (ONOOˉ); however, this direct reaction has been questioned. The antioxidant effects of H2 are also often mediated by heme oxygenase-1 (HO-1), although the exact mechanism remains elusive. Alternatively, it has been proposed that H2 can propagate its effects through the reduction of Fe3+ in various redox-active proteins, which is the focus of this review. It is suggested that a systematic experimental analysis of proteins containing heme prosthetic groups would help elucidate the biological mechanisms of H2 and its development as a medical and restorative therapeutic. (First online: May 10, 2021)

The impact of cobalt insertion on the structural and magnetic properties of nonstoichiometric ZnCoxFe1.7O4 (x >0.3) nanoferrites

A single-phase nanoferrite ZnCoxFe1.7O4 (0.37≤ x ≤0.9) system has been prepared via the citrate autocombustion method. Nonstoichiometry has been progressively enhanced in the synthesized samples by increasing the cobalt content. Both XRD patterns and IR spectra have confirmed a pure cubic phase for all as-prepared samples and for that with × = 0.9 sintered at 700°C. Interestingly, the lattice parameter showed a general decreasing trend with increasing x. The determined crystallite size of as-prepared samples ranged from 17 to 30 nm in agreement with the HRTEM images. For as-prepared samples, the M−H loops exhibited nearly superparamagnetic behavior, while antiferromagnetic behavior was observed for the sintered sample. According to the suggested cation distribution, continuous insertion of Co2+ in the formula unit is compensated by both the reduction of Fe3+ cations to Fe2+ ones and the progressive occupation of Zn2+ in the 16c positions.

Effect of Thermal Treatment at Inert Atmosphere on Structural and Magnetic Properties of Non-stoichiometric Zinc Ferrite Nanoparticles

Zinc ferrite nanoparticles were obtained by chemical methods (co-precipitation and thermal decomposition of metalorganic compounds) and systematically probed with volume (XRD, VSM), microscopic (TEM) and element sensitive probes (ICP-OES, Mössbauer Spectroscopy, XPS, XAFS). Magnetic studies proved the paramagnetic response of stoichiometric ZnFe2O4 (ZF) nanoparticles, while superparamagnetic behavior was observed in as-synthesized, non-stoichiometric ZnxFe3−xO (NZF) nanoparticles. Upon annealing up to 1400 °C in an inert atmosphere, a significant change in the saturation magnetization of NZF nanoparticles was observed, which rose from approximately 50 up to 140 emu/g. We attribute this effect to the redistribution of cations in the spinel lattice and reduction of Fe3+ to Fe2+ during high-temperature treatment. Iron reduction is observed in both ZF and NZF nanoparticles, and it is related to the decomposition of zinc ferrite and associated sublimation of zinc oxide.

One-step synthesis of mixed valence FeOX nanoparticles supported on biomass activated carbon for degradation of bisphenol A by activating peroxydisulfate

A novel FeOX nanoparticles supported biomass activated carbon (BAC/FeOX) composite was prepared through one-pot calcination method with FeCl3 and cherry stone powder as precursors. The carbonization of biomass, reduction of Fe3+, and FeOX anchored on carbon substrate could be achieved at the same time. Characterization with transmission electron microscope (TEM) and scanning electron microscope indicated that nanoscale FeOX distributed uniformly on carbon substrate, and X-ray photoelectron spectroscopy, X-ray diffraction, and high resolution TEM characterization proved that the loaded FeOX was high crystallinity of Fe3O4 and α-Fe0. Bisphenol A (BPA) was used to investigate the degradation performance of BAC/FeOX activating peroxydisulfate (PDS). The ratio of raw materials affected degradation efficiency of BPA intensively through the content, valence state, and dispersibility of FeOX nanoparticles, and the optimal material could degrade 20 mg/L BPA completely in 5 min at 0.1 g/L in the presence of 1 g/L PDS. Free radical determination and quenching experiments indicated that both SO4•− and •OH were involved in BPA degradation. The degradation pathway was proposed based on the identification of degradation intermediates. The facile synthesis method, high activation efficiency, and low-cost and environmental friendly raw materials made the BAC/FeOX-50 an alternative catalyst for organic pollution water treatment.

Logic operation for differentiation and speciation of Fe3+ and Fe2+ based on two‐dimensional metal–organic frameworks with tunable emissions

A facile sensor for selective differentiation and speciation of Fe2+ and Fe3+, which are closely associated with cellular homeostasis and metabolism, was developed based on newly designed two‐dimensional luminescent metal–organic frameworks (2D LMOFs). All the prepared LMOFs [Ln(TCPB)(DMF)3]n (Ln = Tm, LMOF 1; Yb, LMOF 2; and Lu, LMOF 3; H3TCPB = 1,3,5‐tris(1‐(2‐carboxyphenyl)‐1H‐pyrazol‐3‐yl)benzene) display strong tunable emissions by the adjustable metal–organic coordination interactions. The luminescence of LMOFs 1–3 can be quenched by Fe3+ or oxidation of Fe2+ through H2O2 and recovered via reduction of Fe3+ by ascorbic acid (AA). The mechanism for sensing Fe3+ further demonstrates LMOF 1 with the highest sensitivity and the excellent selectivity. Besides, multiple logic gates were also constructed. This work represents a fast, accurate, and sensitive sensor integrated with logic operation capable of detecting Fe3+ and intelligent discrimination and speciation of Fe2+ and Fe3+. The sensing system based on 2D LMOFs displays a convenient approach for developing sensing platforms with tunable luminescence.