Iron Atoms Research Articles

Dual-atoms iron sites boost the kinetics of reversible conversion of polysulfide for high-performance lithium-sulfur batteries

Atomically dispersed metal catalysts have offered significant potential for accelerating sluggish kinetics of lithium polysulfides conversion and inhibiting the shuttle effect, so as to achieve the long-life cycle and high-rate performance of lithium sulfur batteries. However, the end-on adsorption structure between single metal site and polysulfide limits the adsorption capacity and catalytic activity of single atom catalysts. Here, we construct dual-atoms iron sites on nitrogen doped graphene to serve as highly efficient catalyst for lithium sulfur batteries. As expected, the dual-atoms sites can firmly bind polysulfides by forming double Fe-S bonds between polysulfides and the two adjacent iron atoms. Such double-bond adsorption structure is also favorable for electron transfer and polysulfides activation, resulting in reducing the energy barrier and accelerating the reaction kinetics. As a result, the as-obtained dual-atoms iron catalyst can effectively alleviate the shuttle effect and improve the utilization of active sulfur, thus the batteries present high initial capacity of 1615 mAh g−1 at 0.05 C and long-cycle life with a decay rate per cycle as low as 0.015% at 2C over 1000 cycles.

Complex TiC-Ni-based composites joined to steel support by thermal explosion under load: synthesis, microstructure and tribological behavior

ABSTRACT The combustion in thermal explosion mode of reactive mixtures of Ti–Ni–graphite(carbides, borides, oxides), under load, was used to produce complex composite materials, densified and joined to a C55 carbon steel support. The ignition of the exothermic reaction, carried out thanks to the rapid high-frequency heating of a green compact up to 1573 K, was followed by an isothermal holding at 1373 K for 360 s. This procedure ensured a perfect mechanical assembly between the composite material and the steel substrate. SEM analysis and concentration profiles carried out at the interface testified to the interdiffusion of iron and titanium atoms between the two materials. The maximum combustion temperature (Tmax.) exceeding 2200 K induced the appearance of a liquid phase that assisted densification and joining, and in which a part of the additions was dissolved before cooling. The starting chemical composition of reactive mixtures largely determined the microstructure, hardness and tribological behavior of the composites after the process. Thereby, the maximum hardness (1235 HV0.15) and the lowest wear rate (1.824 × 10−6 mm3.N−1.m−1) were obtained in the sample containing TiC, Al2O3 and TiB2 hard phases. The manufactured samples exhibit no deterioration of the composite by spalling, regardless of the starting composition.

Paramagnetic {[Fe(CO)2]2-μ2-η2:η2-η2:η2-(C60)2}2- Dimer Bridged by Iron Atoms and C-C Bonds: Effect of Starting Iron Carbonyls on Structures and Properties of Negatively Charged Iron-Bridged Fullerene Dimers.

The reaction between an excess of Fe(CO)5 with {Cryptand(K+)}(C60•-) produced the salt {Cryptand(K+)}2{[Fe(CO)2]2-μ2-η2:η2-η2:η2-(C60)2}2-·4C6H4Cl2 (1) containing negatively charged iron-bridged fullerene dimers. In these dimers, the C60 cages are linked via two Fe(CO)2 fragments, forming short Fe-C(C60) bonds with a length of 2.070(3) Å and via two intercage C-C bonds with a length of 1.566(3) Å. Interfullerene center-to-center distance is short, being 9.02 Å. Thus, the coordination-induced dimerization of fullerenes is observed in 1. The dimer is negatively charged, with additional negative electron density mainly localized on iron atoms and, to a lesser extent, on the C60 cages, as revealed by optical and electron paramagnetic resonance spectra. These dimers have a diamagnetic singlet ground state with a small singlet-triplet gap of 25 K; consequently, they transfer to a paramagnetic state with two S = 1/2 spins per dimer above 50 K. Previously, different dimers with isomeric structures were obtained starting from {Cryptand(K+)}(C60•-) and Fe3(CO)12. However, these dimers exhibit diamagnetic properties, owing to the formation of a Fe-Fe bond. In contrast, in dimer 1, the Fe atoms are positioned too far apart to form such a bond, preserving the spin on Fe. We assume that both dimers are formed through the same [Fe(CO)3](C60•-) intermediate, but the subsequent interaction of this intermediate with Fe3(CO)12 or its dimerization yields different dimers. Therefore, the starting carbonyls can control the structures and properties of the resulting dimers.

Genetic variations of CYP3A4 on the metabolism of itraconazole in vitro

Itraconazole is a triazole anti-infective drug that has been proven to prevent and treat a variety of fungal and viral infections and has been considered to be a potential therapeutic remedy for COVID-19 treatment. In this study, we aimed to completely evaluate the impacts of Cytochrome P450 3A4 (CYP3A4) variant proteins and drug interactions on the metabolism of itraconazole in recombinant insect microsomes, and to characterize the potential mechanism of substrate selectivity. Incubations with itraconazole (0.2–15 μM) in the presence/absence of lopinavir or darunavir were assessed by CYP3A4 variants, and the metabolite hydroxyitraconazole concentrations were measured by UPLC-MS/MS. Our data showed that when compared with CYP3A4.1, 4 variants (CYP3A4.9, .10, .28 and .34) displayed no significant differences, and 3 variants (CYP3A4.14, .15 and .19) exhibited increased intrinsic clearance (CLint), whereas the remaining 17 variant proteins showed decreased enzyme activities for the catalysis of itraconazole. Moreover, the inhibitory effects of lopinavir and darunavir on itraconazole metabolism varied in different degrees. Furthermore, different changed trend of the kinetic parameters in ten variants (CYP3A4.5, .9, .10, .16, .19, .24, .28, .29, .31, and .33) were observed, especially CYP3A4.5 and CYP3A4.16, and this may be related to the metabolic site-heme iron atom distance. In the present study, we functionally analyzed the effects of 25 CYP3A4 protein variants on itraconazole metabolism for the first time, and provided comprehensive data on itraconazole metabolism in vitro. This may help to better assess the metabolism and elimination of itraconazole in clinic to improve the safety and efficacy of its clinical treatment and also provide new possibilities for the treatment of COVID-19.

Metal-doped fullerenes as promising drug carriers of hydroxycarbamide anticancer: Insights from density functional theory

Assessing an idea of metal-doped fullerenes (MF) as promising drug carriers of hydroxycarbamide; also known as hydroxyurea, (Hyd) anticancer was done in this work by performing density functional theory (DFT) calculations. A model of carbon fullerene was doped by each of iron (Fe), nickel (Ni), and zinc (Zn) transition metal atoms to provide enhanced FeF, NiF, and ZnF doped fullerenes for working towards the Hyd anticancer regarding the drug delivery issues. The model were optimized and their evaluated features indicated a possibility of occurrence of MF → Hyd@MF mechanism through the involving O…M and H…C interactions from the Hyd side to the MF side. The longest recovery time duration was supposed to be found for the Hyd@ZnF complex because of the largest strength and the highest conductance rate variation was supposed to be found for the Hyd@NiF complex because of the smallest energy gap. However, all the complex models were in a reasonable level of formations and electronic variations to be monitored for approaching a sensing or detecting function. In this regard, the enhanced models of FeF, NiF, and ZnF doped fullerenes were found suitable to work as promising carriers of Hyd anticancer regarding the drug delivery issues by the formation of interacting Hyd@FeF, Hyd@NiF, and Hyd@ZnF complexes in meaningful levels of structural and electronic features.

Exploring the potential of isonicotinohydrazide derivatives in N80 steel corrosion control: An integrated approach through synthesis, modeling, and experimentation in acidic environments

N80 carbon steel (N80CS) is recognized for its superior mechanical properties and cost-effectiveness. However, its susceptibility to corrosion, particularly in hydrochloric acid (HCl) environments, necessitates the exploration of corrosion inhibitors. This research centers on the evaluation of N′-[(Z)-(4-bromophenyl)methylidene]pyridine-4-carbohydrazide (BBI) and N′-[(1Z)− 1-(4-chlorophenyl)ethylidene]pyridine-4-carbohydrazide (CEI), green organic compounds from the isonicotinohydrazide family, as potential eco-friendly and non-toxic inhibitors for N80CS in a 15 wt% HCl solution. An array of investigative methods, including weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP), were employed to examine the corrosion inhibition performance of these compounds for the N80CS surface in a strong HCl medium. Our experimental findings demonstrated that the inhibitors' efficiency was concentration-dependent, enhancing as concentrations ranged from 10−4 mol/L to 5 × 10−3 mol/L. Notably, BBI's inhibitory efficiency varied between 97.6% and 99.28%, while CEI's ranged from 94.31% to 98.44%. PDP curves elucidated the capability of BBI and CEI to control both anodic and cathodic reactions, thereby classifying them as mixed-type corrosion inhibitors. The improved inhibition efficiency was evidenced by the decrease in double-layer capacitance, supporting the formation of a protective layer that delays the corrosion process. Consistent with the Langmuir adsorption isotherm model, our results suggested these inhibitors involved in both physical and chemical interactions with the iron atoms on the steel surface. This protective formation was further corroborated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses, which highlighted a significant reduction in the surface roughness of N80CS. Supplementing our experimental data, theoretical investigations using Density Functional Theory (DFT) and semi-empirical Density functional tight binding (DFTB) simulations were conducted. They confirmed the advantageous reactivity of BBI and CEI, attributable to their molecular structures, which promote facile adsorption onto the Fe(110) surface through covalent bonding. This research provides valuable insights into developing non-toxic and environmentally benign corrosion inhibitors for N80CS in acidic conditions.

Effect of magnetic field modification on oxidative stability of myoglobin in sarcoplasm systems

This study aimed to investigate the effect of magnetic fields (0, 3, 6, 12 mT) on the oxidation characteristics of myoglobin (Mb) in the sarcoplasmic protein (SP) system and to understander the underlying mechanism. The metmyoglobin content, Soret band of heme iron porphyrin, protein conformation and molecular weight distribution were measured in different Mb and SP samples. The results showed that the primary oxidation site of hydroxyl radical on Mb was likely to be the porphyrin ring structure and the side chain group of protein rather than the central iron atoms, what’s more, 12 mT magnetic field treatment had an inhibitory effect on the oxidative damage induced by hydroxyl radical.

Structural, electronic and magnetic properties of Fe-doped strontium ruthenates

By employing a combined approach of density-functional theory (DFT) and dynamical mean-field theory (DMFT) calculations, we examine the structural, electronic, and magnetic characteristics of two distinct strontium ruthenates: Sr2RuO4, an unconventional superconductor, and the correlated metal SrRuO3, both at 50% Fe-doping level. In both Sr2Fe0.5Ru0.5O4 and SrFe0.5Ru0.5O3, the original ruthenium (Ru) and the dopant iron (Fe) atoms adopt 3-dimensional and 2-dimensional G-type structures, respectively. The hybridization between Fe-3d and Ru-4d is comparatively weaker than in other double perovskite systems. The interplay between strong correlations and reduced itinerancy results in significant spin splitting at Fe and Ru sites. Consequently, a charge transfer process, along with the super-exchange effect, leads to antiferromagnetically coupled Fe3+ and Ru5+ ions and establishes a semiconducting ferrimagnetic order. Subsequent DMFT calculations demonstrate the persistence of the ferrimagnetic order even at room temperature (300 K). These findings align with prior reports on SrFe0.5Ru0.5O3, thus reinforcing the notion that 3d–4d transition metal oxides hold considerable promise as candidates for high-performance spintronic devices, such as spin-valve sensors and spintronic giant magnetoresistance devices.

Oxohydroxo‐Tellurates(VI) K2[TeO2(OH)4] and K2[Fe2TeO6(OH)2] ⋅ 2H2O from Alkaline Hydroflux

AbstractThe ultra‐alkaline conditions of a hydroflux offer the possibility of redox chemistry far from the electrochemical standard potentials. We explored the possibilities of synthesizing tellurium(VI) compounds, using both tellurium(VI) and tellurium(IV) as starting materials. Colorless, block‐shaped crystals of the oxohydroxotellurate(VI) K2[TeO2(OH)4] were synthesized from (NH4)2TeO4 in a KOH hydroflux at 200 °C. In the triclinic crystal structure, [TeO2(OH)4]2− octahedra are connected via hydrogen bonds to form layers, which are separated from each other by potassium cations. Yellow‐colored platelets of the ferrate(III) tellurate(VI) K2[Fe2TeO6(OH)2] ⋅ 2H2O were obtained by oxidation of TeO2 with H2O2 followed by reaction with Fe(NO3)3 ⋅ 9H2O in a KOH hydroflux. In the monoclinic crystal structure, strongly corrugated anionic layers Fe2TeO6(OH)2]2− are covered with water molecules and separated from each other by potassium cations. The octahedrally coordinated iron(III) atoms form a distorted honeycomb network, in which they are antiferromagnetically coupled at room temperature and in external fields up to at least 7 T.

Structural and electronic characterization of Pb adsorption on clean and Cr or Ni doped Fe(1 0 0) surface: An ab-initio study

Using ab-initio calculations, the interaction of lead adatom on both the clean and doped iron (100) surfaces has been investigated. The adsorption energies show that the hollow site provides a more stable configuration with respect to the top and bridge sites, and, in this position, the lead adatom is more energetically favourable than the iron adatom. On the other hand, lead adsorbed in the hollow site of the iron (100) surface doped with chromium, provides more stable system than the nickel doped surfaces with an iron atom adsorbed in the same position. Detailed investigations of inter-layer distances, bonding mechanisms in terms of the projected density of states, magnetic behaviours, and charge density differences are also presented. Our results give insights in the role of the doping the interaction between lead adatom and iron surface, and then, this study may be exploited in the analysis of the corrosion process due to liquid lead.

Valence Delocalization and Metal-Metal Bonding in Carbon-Bridged Mixed-Valence Iron Complexes.

The carbide ligand in the iron-molybdenum cofactor (FeMoco) in nitrogenase bridges iron atoms in different oxidation states, yet it is difficult to discern its ability to mediate magnetic exchange interactions due to the structural complexity of the cofactor. Here, we describe two mixed-valent diiron complexes with C-based ketenylidene bridging ligands, and compare the carbon bridges with the more familiar sulfur bridges. The ground state of the [Fe2 (μ-CCO)2 ]+ complex with two carbon bridges (4) is S= , and it is valence delocalized on the Mössbauer timescale with a small thermal barrier for electron hopping that stems from the low Fe-C force constant. In contrast, one-electron reduction of the [Fe2 (μ-CCO)] complex with one carbon bridge (2) affords a mixed-valence species with a high-spin ground state (S= ), and the Fe-Fe distance contracts by 1 Å. Spectroscopic, magnetic, and computational studies of the latter reveal an Fe-Fe bonding interaction that leads to complete valence delocalization. Analysis of near-IR intervalence charge transfer transitions in 5 indicates a very large double exchange constant (B) in the range of 780-965 cm-1 . These results show that carbon bridges are extremely effective at stabilizing valence delocalized ground states in mixed-valent iron dimers.

Molecular-orientation-dependent magnetic properties of iron phthalocyanine (FePc) thin films and microwires

The development of molecular magnets plays a major role in emerging organic spintronics applications, as it exhibits both semiconducting and magnetic properties. Herein, we report on the molecular-orientation-dependent magnetic properties of iron phthalocyanine (FePc) thin films and microwires. FePc thin films grown on SiO2 and flexible kapton substrates clearly reveal that the morphology is strongly influenced by the substrates and film thickness. Meanwhile, the molecular stacking orientation of FePc thin films can be tuned by 3, 4, 9, 10-perylenetetracarboxylic dianhydride (PTCDA) templating layer and film thickness. Magnetic hysteresis loops show that the iron atoms are strongly magnetically coupled into ferromagnetic chains at low temperature with high coercivity at 1000 Oe. The magnetization and susceptibility of FePc thin films are dependent on the molecular orientation, and the Curie–Weiss constant is modulated from 24 ± 2 K K to 35 ± 2 K through the templating effect, in which the molecular stacking orientation changes from standing-up to lying-down arrangement. Furthermore, strong orientation dependent ferromagnetism is also observed in low-dimensional η-FePc microwires, in which the Curie–Weiss constants change from 20 ± 2 K to 35 ± 2 K when magnetic field rotated from short wire axis to long wire axis. The ability to fabricate FePc thin films on flexible substrate with controllable molecular orientation and ferromagnetism makes them promising candidates for flexible spintronic devices.

Catalytic activity and anti-passivation of single iron atoms and atomic clusters co-stabilized on carbonized waste polystyrene plastic

Catalytic activity and anti-passivation of single iron atoms and atomic clusters co-stabilized on carbonized waste polystyrene plastic

Computer simulation of Fe epitaxial films on a Cu(100) substrate

The article addresses the problem of modeling thin epitaxial iron films on a Cu (100) substrate by calculating the surface potential. The purpose of the simulation is to determine the film structure. The model uses the paired Lennard-Jones potential to describe the interatomic interaction. We calculate the surface potential of the copper substrate using the first 10 surface atomic layers. The iron atoms in the first layer are placed in the minima of the surface potential. The surface potential of the monoatomic iron layer and the 9 copper layers underneath determine the position of the second iron layer. The position of atoms in the following layers is formed on the basis of similar calculations. Calculations show that the copper substrate stabilizes the fcc crystal lattice in the iron film at low temperatures. Bulk iron samples at low temperatures have a bcc crystal lattice. The period of the iron lattice along the substrate is equal to the period of the copper lattice. The crystal lattice period of iron perpendicular to the substrate has an intermediate value between the values for copper and for γ-ferrum. The interface effect causes additional vertical deformations in the first two layers of iron above the substrate.

Racemic cis-bis-[bis-(pyrimidin-2-yl)amine-κN]bis(dicyanamido-κN1)iron(II) dihydrate: synthesis, crystal structure and Hirshfeld surface analysis.

The title compound, [Fe(C2N3)2(C8H7N5)2]·2H2O, has been synthesized solvothermally and characterized by single-crystal X-ray diffraction. The octa-hedral iron coordination polyhedron contains two di(pyrimidin-2-yl)amine ligands coordinated in a bidentate fashion, and two monodentate dicyanimido ligands, each coordinated via a terminal N atom, with the latter in a cis orientation. The ligand configuration about the iron atom is chiral, although the compound crystallizes as a racemic mixture: the Fe-N distances (> 2.07 Å) are characteristic of high-spin iron(II). In the crystal, an extensive series of N-H⋯N, O-H⋯N and O-H⋯O hydrogen bonds links the independent mol-ecular components into a three-dimensional framework. The H atoms of both water mol-ecules are disordered. The structure also features some π-π and anion-π inter-actions. The inter-molecular inter-actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots. Comparisons are made with some related compounds.

Ternary sulfide nanoparticles anchored in carbon bubble structure for oxygen evolution reaction

The synergistic effect and unique interfacial structure of ternary transition metal (Co, Ni, Fe) sulfides are significant in improving the catalytic performance of oxygen evolution reaction (OER). Herein, the ultrathin Co0.3Ni0.3Fe0.2S ternary sulfide nanoparticles (Co0.3Ni0.3Fe0.2S NPs) anchored in carbon bubble structure with rich pore structures (Co0.3Ni0.3Fe0.2S NPs/C) were firstly constructed via a cost-effective and general solid-phase synthesis strategy. Co0.3Ni0.3Fe0.2S NPs/C has a crystalline structure of Co1−xS, accompanying the shift of diffraction peaks, which indicate the doping of nickel and iron atoms into Co1−xS lattice. Co0.3Ni0.3Fe0.2S NPs/C catalyst has good OER activity with a low overpotential of 322 mV at 100 mA cm−2 in 1.0 M KOH electrolyte, superior to single metal sulfide synthesized at the same conditions. More importantly, the Co0.3Ni0.3Fe0.2S NPs/C catalyst possesses excellent stability with a low current density decrease in the continuous 336 h I-t test. The good catalytic intrinsic activity may originate from the synergistic effect among the highly exposed Fe, Co, and Ni sulfide grown on the porous carbon bubbles and the unique reconstruction structure formed during the OER process. This work provides some reference significance for the systematic study of the synergistic effects between multicomponents and the relationship between interfacial modulation and OER.

Synthesis and Electrochemical Investigation of Phosphine Substituted Diiron Phosphadithiolate Complexes

AbstractThis work reports on ligand exchange reactions between a [FeFe] hydrogenase model containing the higher homologue (PhosDT) and phosphines selected to cover a variety of electronic properties and possible coordination modes. Additionally, the amount of the phosphines and the reaction temperature were varied to study the formation of complexes with multiple phosphines or altered binding modes. Due to steric effects caused by the position of the bridgehead, the phosphines bind preferentially at the more accessible iron centre on the phosphinate averted side. While all ligand exchanges resulted in a ligand‐specific main product at room temperature, reflux conditions induced decomposition in case of PhosDT‐(κ2‐dppe) and PhosDT‐(κ2‐dppv) and a change in the binding mode for the dppm containing complex. Moreover, we highlight two novel iron complexes obtained as side products of the reactions with dppe and dppv, while in case of dppm an additional model with two bridging phosphine ligands was generated. Finally, the six novel phosphine substituted PhosDT models were electrochemically investigated, revealing a cathodic shift compared to the starting material due to the increased electron density at the iron atoms. Moreover, the models with monodentate ligands exhibit a different CV pattern for the FeIFeI/FeIFe0 process than complexes with bidentate phosphines.

Pyrolysis Enzymolysis-Treated Pomelo Peel: Porous Carbon Materials with Fe-Nx Sites for High-Performance Supercapacitor and Efficient Oxygen Reduction Applications.

This paper proposes a different strategy for deriving carbon materials from biomass, abandoning traditional strong corrosive activators and using a top-down approach with a mild green enzyme targeted to degrade the pectin matrix in the inner layer of pomelo peel cotton wool, inducing a large number of nanopores on its surface. Meanwhile, the additional hydrophilic groups produced via an enzymatic treatment can be used to effectively anchor the metallic iron atoms and prepare porous carbon with uniformly dispersed Fe-Nx structures, in this case optimizing sample PPE-FeNPC-900's specific surface area by up to 1435 m2 g-1. PPE-FeNPC-900 is used as the electrode material in a 6 M KOH electrolyte; it manifests a decent specific capacitance of 400 F g-1. The assembled symmetrical supercapacitor exhibits a high energy density of 12.8 Wh kg-1 at a 300 W kg-1 power density and excellent cycle stability. As a catalyst, it also exhibits a half-wave potential of 0.850 V (vs. RHE) and a diffusion-limited current of 5.79 mA cm-2 at 0.3 V (vs. RHE). It has a higher electron transfer number and a lower hydrogen peroxide yield compared to commercial Pt/C catalysts. The green, simple, and efficient strategy designed in this study converts abundant, low-cost waste biomass into high-value multifunctional carbon materials, which are critical for achieving multifunctional applications.

Computational Study on the Water Corrosion Process at Schreibersite (Fe2NiP) Surfaces: from Phosphide to Phosphates.

Phosphorus (P) is a fundamental element for whatever form of life, in the same way as the other biogenic macroelements (SONCH). The prebiotic origin of P is still a matter of debate, as the phosphates present on earth are trapped in almost insoluble solid matrixes (apatites) and, therefore, hardly available for inclusion in living systems in the prebiotic era. The most accepted theories regard a possible exogenous origin during the Archean Era, through the meteoritic bombardment, when tons of reactive P in the form of phosphide ((Fe,Ni)3P, schreibersite mineral) reached the primordial earth, reacting with water and providing oxygenated phosphorus compounds (including phosphates). In the last 20 years, laboratory experiments demonstrated that the corrosion process of schreibersite by water indeed leads to reactive phosphates that, in turn, react with other biological building blocks (nucleosides and simple sugars) to form more complex molecules (nucleotides and complex sugars). In the present paper, we study the water corrosion of different crystalline surfaces of schreibersite by means of periodic DFT (density functional theory) simulations. Our results show that water adsorbs molecularly on the most stable (110) surface but dissociates on the less stable (001) one, giving rise to further reactivity. Indeed, subsequent water adsorptions, up to the water monolayer coverage, show that, on the (001) surface, iron and nickel atoms are the first species undergoing the corrosion process and, in a second stage, the phosphorus atoms also get involved. When adsorbing up to three and four water molecules per unit cell, the most stable structures found are the phosphite and phosphate forms of phosphorus, respectively. Simulation of the vibrational spectra of the considered reaction products revealed that the experimental band at 2423 cm-1 attributed to the P-H stretching frequency is indeed predicted for a phosphite moiety attached to the schreibersite (001) surface upon chemisorption of up to three water molecules.

Functionalization of bacterial microcompartment shell interior with cysteine containing peptides enhances the iron and cobalt loading capacity.

Bacterial microcompartments (BMCs) are prokaryotic organelles involved in several biochemical processes in bacterial cells. These cellular substructures consist of an icosahedral shell and an encapsulated enzymatic core. The outer shells of BMCs have been proposed as an attractive platform for the creation of novel nanomaterials, nanocages, and nanoreactors. In this study, we present a method for functionalizing recombinant GRM2-type BMC shell lumens with short cysteine-containing sequences and demonstrate that the iron and cobalt loading capacity of such modified shells is markedly increased. These results also imply that a passive flow of cobalt and iron atoms across the BMC shell could be possible.