Iron Nanoclusters Research Articles

Non-Enzymatic Detection of Cardiac Troponin-I with Graphene Oxide Quenched Fluorescent Iron Nanoclusters (FeNCs).

Cardiac troponin I (cTnI) is the most resorted biomarker for the detection of cardiovascular disease (CVD). The means of rapid quantification of cTnI levels in the blood can substantially minimize the risk of acute myocardial infarction and heart failure. A sensor for the non-enzymatic evaluation of cardiac troponin-I has been developed using fluorescent iron nanoclusters via a one-pot synthesis employing (BSA) as the template and reducing agent, and hydrogen peroxide as the additive. The fluorescence of Iron Nanocluster is quenched with graphene oxide (GO) via fluorescence resonance energy transfer (FRET) between conjugate iron nanoclusters and graphene oxide. The sensor shows a low detection limit of 0.011 ng/mL. The benefits of utilizing a non-enzymatic probe for detecting cardiac troponin I is that it avoids the need for enzymes and hence is economical, stable, and less impacted by environmental conditions such as temperature and pH. Non-enzymatic probes are more useful for clinical use since they are more stable and have a longer shelf life. The developed non-enzymatic probes are also highly selective and sensitive to the target analyte, making them suitable for the direct detection of cardiac troponin I in actual biological samples.

Tailoring the Heterointerfaces of Earth-Abundant Transition-Metal Nanoclusters on Nickel Oxide Nanosheets for Enhanced Overall Water Splitting through Electronic Structure Optimization.

Evolving highly competent and economical electrocatalysts for alkaline water electrolysis is crucial in renewable hydrogen energy technologies. The slow hydrogen evolution reaction (HER)/oxygen evolution reaction (OER) kinetics under alkaline electrolytes, still, has troubled developments in high-performance green hydrogen production systems. Herein, we demonstrate the tailoring of the interface of earth-abundant transition-metal nanoclusters (MNCs), including iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu) nanoclusters on nickel oxide nanosheets (M NCs|NiO NS) through metal-support interaction for enriched overall water splitting under an alkaline electrolyte. The strong metal-metal oxide interaction allows alteration of the binding capabilities of hydrogen ions (*H) and hydroxyl ions (*OH) on Ni electrodes. Specifically, the robust interaction between Fe and NiO reveals optimized binding of H* and OH* energies, facilitating the water-splitting reaction under an alkaline electrolyte. In addition, the improved HER/OER catalytic activity is attained with the Fe NCs|NiO NS with small overpotentials of ∼62.0 and ∼380.0 mV for the HER and OER, respectively, a high mass activity of ∼90.0 A g-1, a turnover frequency of ∼5.94 s-1, and long-lasting stability via offering abundant electrochemical active sites, three-dimensional (3D) morphologies, and high dispersion of nanoclusters that provide effective charge and mass transport processes. This study provides a promising strategy for the effective design of efficient bifunctional electrocatalysts based on earth-abundant materials for alkaline water electrolyzers.

Reaction Dynamics of CO2 Hydrogenation on Iron Catalysts Using ReaxFF Molecular Dynamics Simulation.

The conversion of CO2 to hydrocarbons using catalysts is a promising route to utilize CO2 and produce more valuable chemicals in a sustainable manner. Recent studies have shown that iron-based catalysts perform well for the hydrogenation of CO2. While the hydrogenation reaction mechanism in the gas phase is straightforward, when catalyzed by iron it has been demonstrated to involve various chemical transformations, and the selectivity and conversion are strongly dependent on the particle size. To further investigate the dependence of the reactivity of iron catalysts on cluster size, we performed reactive molecular dynamics simulations using the ReaxFF force field (ReaxFF-MD) for iron nanoclusters of various sizes in a CO2 and H2-rich environment. We demonstrated that the homogeneous hydrogenation of CO2 was correctly described by this ReaxFF model. The dissociation mechanism of CO2 on the Fe4, Fe16 clusters, and the bcc(100) Fe slab agrees with previous DFT results. The ReaxFF-MD simulations suggest a strong dependence of reactivity on the cluster size, with the Fe4 cluster having the highest reactivity. We show that ReaxFF-MD provides a route to understand reaction mechanisms in these nonequilibrium reactive processes where fast processes and local minima are important.

The Fluorescent Detection of Glucose and Lactic Acid Based on Fluorescent Iron Nanoclusters.

In this paper, a novel fluorescent detection method for glucose and lactic acid was developed based on fluorescent iron nanoclusters (Fe NCs). The Fe NCs prepared using hemin as the main raw material exhibited excellent water solubility, bright red fluorescence, and super sensitive response to hydrogen peroxide (H2O2). This paper demonstrates that Fe NCs exhibit excellent peroxide-like activity, catalyzing H2O2 to produce hydroxyl radicals (•OH) that can quench the red fluorescence of Fe NCs. In this paper, a new type of glucose sensor was established by combining Fe NCs with glucose oxidase (GluOx). With the increase in glucose content, the fluorescence of Fe NCs decreases correspondingly, and the glucose content can be detected in the scope of 0-200 μmol·L-1 (μM). Similarly, the lactic acid sensor can also be established by combining Fe NCs with lactate oxidase (LacOx). With the increase in lactic acid concentration, the fluorescence of Fe NCs decreases correspondingly, and the lactic acid content can be detected in the range of 0-100 μM. Furthermore, Fe NCs were used in the preparation of gel test strip, which can be used to detect H2O2, glucose and lactic acid successfully by the changes of fluorescent intensity.

Boosting Oxygen Reduction Reaction with Fe-Based Single-Atom Catalysts: The Role of Cluster Interactions

Fuel cells (FCs) have emerged as a promising alternative for efficient electricity production in the future [1]. However, their widespread commercialization is hindered by their prohibitive cost due to the large amount of platinum used in these electrochemical systems [2]. Platinum is used to accelerate the unfavorable kinetics of the cathodic oxygen reduction reaction (ORR) [3]. To achieve large-scale and cost-effective development of FCs, it is essential to find high-performance platinum-free catalysts. Two solutions are mainly reported in the literature: the development of non-precious metal-based carbon catalysts and metal-free carbon catalysts. However, the work reported on these two types of carbon catalysts is sometimes contradictory regarding the actual nature of the active sites and the mechanisms of reduction of oxygen molecules on the catalyst [4].Pyrolyzed metal-nitrogen-carbon (M-N-C) catalysts for the ORR, especially single-atom catalysts (SACs), have been widely studied because they exhibit excellent electrocatalytic performance, thanks to the high content of metal atoms anchored on a carbon support [5]. Recent research has indicated that the combination of single-atom active sites with metal nanoclusters can further improve the catalytic activity, but the underlying mechanism remains unclear [6]. Therefore, it is necessary to develop model catalysts based on both single-atoms and nanoclusters to better understand their catalytic activity.In this work, we prepared nitrogen-doped and iron-doped carbon catalysts (called Fe-NC below) with precise control of the type of iron in the material. First, the functionalization of an activated carbon was performed by carbonizing it under air in the presence of urea. Then, the sample was placed in an autoclave for hydrothermal treatment in the presence of FeCl3.6H2O to allow the incorporation of iron, and thermal post-treatment was applied to synthesize model catalysts (Fig. 1a). The precursor ratio and final pyrolysis temperature were adjusted and optimized to produce either iron-based single atoms (SA) (here referred to as FeSA-NC) or atomic clusters (AC) associated with single atoms (here referred to as FeSA+AC-NC). The results show that the iron-based catalysts exhibit outstanding catalytic activity (Fig. 1b) and durability (Fig. 1c) in alkaline medium for the ORR, even better than commercial Pt (20 wt.%)/C in the case of FeSA+AC-NC. The analysis provided insight into the development of highly efficient multifunctional electrocatalysts, where the presence of iron nanoclusters was found to be a crucial determinant of the catalytic activity for the ORR.[1] M.K. Debe, Electrocatalyst approaches and challenges for automotive fuel cells, Nature. 486 (2012) 43–51. https://doi.org/10.1038/nature11115.[2] C. Sealy, The problem with platinum, Mater. Today. 11 (2008) 65–68. https://doi.org/10.1016/S1369-7021(08)70254-2.[3] M. Borghei, J. Lehtonen, L. Liu, O.J. Rojas, Advanced Biomass-Derived Electrocatalysts for the Oxygen Reduction Reaction, Adv. Mater. 30 (2018) 1703691. https://doi.org/10.1002/adma.201703691.[4] A. Dessalle, J. Quílez-Bermejo, V. Fierro, F. Xu, A. Celzard, Recent progress in the development of efficient biomass-based ORR electrocatalysts, Carbon. 203 (2023) 237–260. https://doi.org/10.1016/j.carbon.2022.11.073.[5] K. Liu, J. Fu, Y. Lin, T. Luo, G. Ni, H. Li, et al., Insights into the activity of single-atom Fe-N-C catalysts for oxygen reduction reaction, Nat. Commun. 13 (2022) 2075. https://doi.org/10.1038/s41467-022-29797-1.[6] X. Wan, Q. Liu, J. Liu, S. Liu, X. Liu, L. Zheng, et al., Iron atom–cluster interactions increase activity and improve durability in Fe–N–C fuel cells, Nat. Commun. 13 (2022) 2963. https://doi.org/10.1038/s41467-022-30702-z. Figure 1

A novel fluorescent method for the detection of Cu2+ and Zn2+ ions based on zero-valent iron nanoclusters

Zero-valent iron nanoclusters (Fe NCs), as an emerging iron-based nanomaterial, were widely utilized in water treatment and antibiosis due to its amazing catalytic activity, superior adsorption ability, and abundant iron reserves. In this work, we developed a novel method for the fluorescent detection of Cu2+ and Zn2+ ions based on the zero-valent iron nanoclusters that exhibited bright red fluorescence and excellent stability in aqueous solution. The Fe NCs were successfully used for the detection of Cu2+ ions based on the fluorescence quenching at 616 nm in the range of 0–10 μmol·L−1 with 0.037 μmol·L−1 of detection limit. In addition, Fe NCs were used for detection of Zn2+ ions based on the emerging fluorescence at 580 nm in the range of 0–20 μmol·L−1 with 0.016 μmol·L−1 of detection limit.

Ligand effects on thiols protected iron nanoclusters towards photoluminescence and antibacterial studies

Over the past few decade, thiolate-protected metal nanoclusters have gained great attention due to their high surface-to-volume ratio and greater surface area which finds applications in electronic, optical, magnetic, and biomedical fields. Herein, we report the tailoring of surface ligands protected over the ultra-small iron nanoclusters using three different thiols namely glutathione (GSH), 3-mercaptopropionic acid (MPA) and 3-mercaptopropane sulfonate (MPS). To understand the role of surface ligands on as prepared FeNCs (namely FeGSH, FeMPA and FeMPS NCs) was characterized by photophysical and bioimaging studies. The HRTEM and AFM results confirmed that these FeGSH, FeMPA and FeMPS NCs were in the average size range of 1–6 nm. The varying functionality and robustness of GSH, MPA and MPS protected over these individual FeNCs resulted in tunable quantum yields of 5.6 %, 5.8 % and 2.1 % for FeGSH, FeMPA and FeMPS NCs respectively. Further, these three FeNCs were investigated for cell viability and fluorescent microscopic analysis with the MCF-7 breast cancer cell line. The cell viability of FeGSH, FeMPA and FeMPS NCs with cancer cell line were found to be 96.62 %, 98.31 % and 93.29 % respectively for a fixed concentration range of 0 to 100 nM. The Phase contrast and fluorescent microscopy results confirm FeNCs induction which demonstrates that the cells were noncytotoxic and biocompatible for various applications, and this was further validated by the MTT test. The in vitro results imply that the ligand shell thickness and functionality here resulted in varying bioimaging results and antibacterial properties.

Mechanical insight into direct singlet oxygen generation pathway: Pivotal role of FeN4 sites and selective organic contaminants removal

Herein, the systematic and novel formation pathway of singlet oxygen (1O2) on single iron atom during advanced oxidation process was investigated and revealed. Graphitic carbon matrix supported single iron atom and iron nanoclusters configurations as model catalysts were synthesized via calcinating Prussian blue, which showed admirable catalytic efficiency towards bisphenol A (BPA) oxidation even under high salinity conditions. 1O2 directly generated on Fe-pyridinic N moiety bonded with terminal O of PMS (HSO5-) was proposed as predominant reactive species. Experimental results and theoretical analysis further detailly demonstrated the evolutionary pathway of 1O2 formation, which occurred through the interaction of two O atoms from adsorbed PMS, accompanying two HSO4- molecules generation with the lowest energy barrier. This study proposed novel insights into direct 1O2-modulated mechanism via Fe-N4 configuration, providing essential atomic-scale understanding of FeNx/PMS based Fenton-like system, as well as a new strategy for the practical environmental remediation with high salinity.

An ultra-small fluorescence zero-valent iron nanoclusters selectively kill gram-positive bacteria by promoting reactive oxygen species generation

A list of the most dangerous bacteria that are multiple-drug resistance has been published by WHO, among which are various Gram-positive bacteria related with serious healthcare and community-associated infection. An effort is called for developing new strategies to combat the resistance, and nanomaterial-based approaches provide an ideal potential to mitigate the antimicrobial resistance as an alternative to antibiotics. Nanoscale zero-valent iron particles exhibited a good antimicrobial activity by triggering Fenton reaction, however, no zero-valent iron nanoclusters are developed as antimicrobial medical materials. In this work, a novel ultra-small zero-valent iron nanoclusters (usZVIN) was synthesized by one-step reduction in aqueous solutions, which exhibited bright red fluorescence at 616 nm. Interestingly, the usZVIN displayed an excellent selectively antibacterial activity against Gram-positive bacteria, and little effects on Gram-negative bacteria. The killing efficiency of usZVIN against S. aureus can reach 100 % with a concentration of 40 μg mL−1 after 1 h incubation, whereas there is no killing effect of usZVIN against E.coli even with a concentration of 900 μg mL−1 for 4 h. The antimicrobial mechanism of usZVIN was demonstrated to be the intracellular reactive oxygen species (ROS) production triggered by usZVIN due to its excellent peroxidase-like activity. Collectively, our findings suggested that usZVIN is a good medical-material candidate for fighting against Gram-positive bacterial infections, especially when we need leave beneficial Gram-negative bacteria intact.

The synthesis of tunable fluorescence iron nanoclusters and the detection of pH value and hydroxyl radical

In this work, we developed a novel route for the synthesis of fluorescent iron nanoclusters (Hb-Fe NCs) in aqueous solution with natural protein and amino acid as the original materials. Moreover, the fluorescence emission of Hb-Fe NCs were adjustable from red to blue fluorescence by regulating the dosage of sodium hydroxide in the synthesis process. We have examined the fluorescence response of Hb-Fe NCs in various temperature, metal ions or biomolecules environment, and exhibited excellent stability in the complex environment. Furthermore, the fluorescence of Hb-Fe NCs gradually enhanced as the pH value of environment increased from 5.0 to 9.0. More importantly, the fluorescence of Hb-Fe NCs can be inhibited significantly by hydroxyl radical (OH·).

Supramolecular complex derived carbon nanotubes decorated with iron single atoms and nanoclusters as efficient bifunctional oxygen electrocatalysts for rechargeable Zn-air batteries

The great attention of rechargeable Zn-air battery has motivated extensive research on the development of inexpensive, highly efficient, and robust noble-metal-free bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, a supramolecular complex derived strategy was used to prepare bamboo-like carbon nanotubes with abundant Fe single atoms and sub-nanometer clusters anchored on tube walls. When served as a bifunctional ORR/OER electrocatalyst, this hybrid showed a small overpotential gap of 0.713 V and excellent stability. More importantly, a large power density of 213 mW cm−2 and stable long-time round-trip charge-discharge performance were achieved for the assembled rechargeable Zn-air batteries. Density functional theory calculations revealed that atomic Fe–N4 moiety in the catalyst could be the essence of high ORR activity, while atomic Fe–N4 moiety coupled sub-nanometer cluster significantly reduces the OER energy barrier. This work provides an effective strategy for the preparation of high-performance and robust oxygen electrode catalysts as well as a significant new insight on the catalytic mechanisms, helping to realize significant advances in energy devices.

In Ukrainian

Metal composites modified with various heteroatoms, such as N, B, Si, are used to obtain matrix composites with specified parameters with the strongest adhesive-cohesive bonds between metal atoms and a carbon nanoparticle. Such carbon nanoparticles functionalized with heteroatoms are promising for many metal composites. One of the interesting and promising metals as a matrix for such research work is iron. To predict the specifics of the interaction of iron with the surface of carbon nanomaterials supplemented with heteroatoms of different chemical structure, it is advisable to model such processes using quantum chemistry methods. The aim of the work was to find out the effect of temperature on the chemical interaction of iron clusters with native, boron-, silicon-, and nitrogen-containing graphene-like planes (GLP). The results of the calculations show that the highest value of the energy effect of the chemical interaction for the native graphene-like plane is +204.3 kJ/mol, in the case of calculations both by the B3LYP/6-31G(d,p) method and by the MP2/6-31G(d, p) (+370.7 kJ/mol). The lower value of the energy effect is found in the presence of nitrogen atoms in the composition of the graphene-like plane. This value is even lower for the interaction of iron dimers with a silicon-containing carbon nanocluster. The lowest values of the energy effect, calculated by both methods, are characteristic of the boron-containing graphene-like plane. In particular, for the B3LYP/6-31G(d,p) method, the value of the energy effect of the reaction is ‑210.5 kJ/mol, and for the MP2/6-31G(d,p) method this value is +16.6 kJ/mol. The presence of boron atoms in the composition of the nanocarbon matrix best contributes to the interaction with the iron nanocluster, regardless of the chosen research method. The dependence curves of the Gibbs free energy of the interaction of iron dimers with a graphene-like plane and its derivatives in all cases qualitatively correlate with similar energy effects. In addition, in all cases, the values of the Gibbs free energy increase with increasing temperature.

Highly durable iron single-atom catalysts for low-temperature zinc-air batteries by electronic regulation of adjacent iron nanoclusters

Durability of carbon-supported Fe single-atom catalysts has remained a critical issue for metal-air batteries. Herein, Fe single atoms with adjacent Fe nanoclusters supported on nitrogen-doped carbon aerogels (NCA/FeSA+NC) are prepared via a facile two-step pyrolysis procedure using biomass hydrogels as the precursor and template. The Fe atomic centers are found to exhibit an increased 3d electron density and decreased magnetic moment by the nanoclusters. This markedly enhances the oxygen reduction reaction activity and anti-oxidation stability of the FeN4 sites, as compared to the nanocluster-free counterparts. With NCA/FeSA+NC as the cathode catalysts, a flexible zinc-air battery delivers a remarkable performance even at −40 °C, with an open circuit voltage as high as 1.47 V, power density 49 mW cm−2, and excellent durability after 2300 continuous recharging/charging cycles. The performance is even higher at ambient temperature. These results highlight the significance of electronic manipulation in enhancing the durability of single atom catalysts.

The morphology and magnetic properties of iron nanoclusters decorated multiwall carbon nanotubes

Vapor phase growth of magnetic nanoclusters on different substrates alters their physical, chemical, and magnetic properties. In this work, DC magnetron sputtering with inert gas condensation (IGC) technique was used to produce iron (Fe) based nanoclusters on multiwall carbon nanotubes (MWCNTs) and silicon (Si) substrates. For comparison, simple electron beam evaporation technique was used to deposit Fe on the same type of substrates. We observed that surface of the electron beam evaporation sample was oxidized from Fe to γ-Fe2O3 when exposed to air. IGC growth Fe/Si sample exhibited a magnetic negative exchange bias. Core level binding energy (BE) and the valance band maximum (VBM) shifts were affirmed the formation of a semi-metallic phase. There was substantial enhancement in the saturation magnetization in the IGC sample up to five times compared to the evaporated sample which can be applied to the magnetic applications.

Markedly boosted peroxymonosulfate- and periodate-based Fenton-like activities of iron clusters on sulfur/nitrogen codoped carbon: Key roles of a sulfur dopant and compared activation mechanisms

Highly dispersed iron nanoclusters on carbon (FeNC@C) hold great promise for wastewater purification in Fenton-like reactions. The microenvironment engineering of central Fe atom is promising to boost the activation capacity of FeNC@C, which is however remains a challenge. This study developed a self-sacrificed templating strategy to S, N-codoped carbon supported Fe nanoclusters (FeNC@SNC) activator and find the key role of sulfur heteroatoms in regulating the electron structure of Fe sites and final activation property. Investigations revealed that the FeNC@SNC composite exhibited unusual bifunctional activity in both peroxymonosulfate (PMS)- and periodate (PI)-based Fenton-like reactions. We also offered insights into the differences between the degradation of organics by the FeNC@SNC/PMS and FeNC@SNC/PI systems. Specifically, under identical conditions, the FeNC@SNC/PMS system delivered a higher oxidation capability and stronger resistance to nontarget matrix constituents, but showed more severe Fe leaching than the FeNC@SNC/PI system. Furthermore, while mediated electron-transfer process was identified as the major route for pollutant decomposition in both systems, the high-valent Fe-oxo species [Fe (IV)] was the auxiliary reactive species found only in the FeNC@SNC/PMS system. Based on these findings, our results provide profound insights into the design of active and durable Fe-based activators toward highly efficient Fenton-like reactions.

Influence of the size of iron nanoclusters on their magnetization

The size of iron nanocrystals significantly affects the value of their magnetization. However, an adequate model of the structure of nanocrystalline formations comprising different numbers of iron atoms still does not exist. In this work, spatial models of nanocrystalline iron clusters differing in configuration and the number of their constituent atoms are constructed. Tetrahedrally close-packed cluster assemblies of iron atoms are taken as the basis for the proposed structures of nanocrystals. The spectra of the density of electronic states for the proposed clusters are constructed using the theory of the electron density functional. The calculation was carried out by the method of scattered waves in accordance with the band theory of crystals. The appearance of magnetization in tetrahedral close-packed cluster formations is associated with excited electronic states of atoms located on the surface of the nanocluster. Excited atoms have an increased electron density, that is, electrons are able to transition to states with higher energy, approaching the Fermi energy. In this case, the Stoner criterion necessary for the occurrence of magnetization is fulfilled. The configurations of electrons with spin up and down differ, which is why uncompensated magnetic moments appear. It is shown that the proposed models of iron nanoclusters are in satisfactory agreement with the known experimental data.

Simultaneously Integrate Iron Single Atom and Nanocluster Triggered Tandem Effect for Boosting Oxygen Electroreduction.

Atomically nitrogen-coordinated iron atoms on carbon (FeNC) catalysts are emerging as attractive materials to substitute precious-metal-based catalysts for the oxygen reduction reaction (ORR). However, FeNC usually suffers from unsatisfactory performance due to the symmetrical charge distribution around the iron site. Elaborately regulating the microenvironment of the central Fe atom can substantially improve the catalytic activity of FeNC, which remains challenging. Herein, N/S co-doped porous carbons are rationally prepared and are verified with rich Fe-active sites, including atomically dispersed FeN4 and Fe nanoclusters (FeSA-FeNC@NSC), according to systematically synchrotron X-ray absorption spectroscopy analysis. Theoretical calculation verifies that the contiguous S atoms and Fe nanoclusters can break the symmetric electronic structure of FeN4 and synergistically optimize 3d orbitals of Fe centers, thus accelerating OO bond cleavage in OOH* for improving ORR activity. The FeSA-FeNC @NSC delivers an impressive ORR activity with half-wave-potential of 0.90 V, which exceeds that of state-of-the-art Pt/C (0.87 V). Furthermore, FeSA-FeNC @NSC-based Zn-air batteries deliver excellent power densities of 259.88 and 55.86 mW cm-2 in liquid and all-solid-state flexible configurations, respectively. This work presents an effective strategy to modulate the microenvironment of single atomic centers and boost the catalytic activity of single-atom catalysts by tandem effect.

Efficient conversion of Kraft lignin to guaiacol and 4-alkyl guaiacols over Fe-Fe3C/C based catalyst under supercritical ethanol

One-pot lignin catalytic depolymerization (LDP) under supercritical ethanol was an effective strategy for converting lignin into value-added aromatic monomers. However, complex substructure and linkages in lignin limited the development of gaining high selectivity aromatic monomers. In this study, carbon supported Fe-Fe3C/C based catalysts prepared using high temperature reducing method were employed as LDP catalysts. GC–MS and 1H−13C 2D HSQC NMR results of lignin oil display that the optimum Fe-C-700 catalyst can converted lignin into lignin oil consisting of guaiacol and 4-alkyl guaiacols with an 86 wt% of selectivity at a 48 wt% of conversion rate. The XRD, Raman, HRTEM, TEM-EDS mapping, and the XPS characterization results of Fe-Fe3C/C catalysts show that the graphitized and amorphous carbon encapsulates iron carbide nanocrystal and metal iron nanoclusters. The NH3-TPD and CO2– TPD profiles revealed a system of strong acid-base sites on Fe-Fe3C/C catalysts which means acid sites are responsible for C-O bonds breaking and base sites are responsible for cleavage of C–C bonds. Metal Fe (0) was considered to be a key factor to activate the hydrogen source in order to promote the hydrogenation process.

Supramolecular Complex Derived Carbon Nanotubes Decorated with Iron Single Atoms and Nanoclusters as Efficient Bifunctional Oxygen Electrocatalysts for Rechargeable Zn-Air Batteries

Supramolecular Complex Derived Carbon Nanotubes Decorated with Iron Single Atoms and Nanoclusters as Efficient Bifunctional Oxygen Electrocatalysts for Rechargeable Zn-Air Batteries

The Synthesis of Tunable Fluorescence Iron Nanoclusters and the Detection of Ph Value and Hydroxyl Radical

The Synthesis of Tunable Fluorescence Iron Nanoclusters and the Detection of Ph Value and Hydroxyl Radical