Nano-sized Fe2O3 Research Articles

Synthesis of uniform Fe2O3@Y2O3 yolk−shell nanoreactors as chemical looping oxygen carriers

Iron-based materials are extensively employed as oxygen carriers in chemical looping processes, but their long-term performance is often inhibited by sintering and agglomeration. Here, we developed a yolk–shell structured Fe2O3@Y2O3 oxygen carrier, with each unit consisting of a Y2O3 shell encapsulating a nano-sized Fe2O3 core. The Y2O3 shell could protect the redox-active cores from sintering, and the void between the yolk and the shell is capable of tolerating cyclic volume and phase changes. During the simulated chemical looping cycles at 600 °C, the Fe2O3@Y2O3 oxygen carriers exhibit a consistent oxygen carrying capacity of 3 wt% over 50 cycles, without any distinguishable structural deterioration. With rational structure optimization, the Fe2O3@Y2O3 oxygen carriers with porous shell could enhance the mass transfer across the shell and enable higher reaction rates. The satisfactory sintering resistance of the Fe2O3@Y2O3 nanostructure demonstrates the feasibility of employing well defined yolk–shell structured oxygen carriers for chemical looping applications.

Long-lifespan sodium ion capacitors enabled by in-situ electrochemically induced graphitization and rearrangement of carbon layers in Fe2O3@C modified vertical-aligned carbon nanotubes

Developing high-capacity anodes with fast kinetics and stable structure is critical for the effective implementation of sodium ion capacitors (SICs). In this study, Fe2O3@C nanoparticles modified vertically aligned carbon nanotubes (VACNTs) composites are designed and employed as SIC anodes through a two-step chemical vapor deposition (CVD) process with the aid of a refined Fe3O4/AlOx dispersion catalyst. With nano-sized Fe2O3 coated with defected carbon layers sufficiently loading onto the VACNTs substrates, the resulting composites demonstrate remarkable sodium storage properties, with a high areal specific capacity (1.26 mAh cm−2 at 0.2 mA cm−2) and rate performance (0.19 mAh cm−2 at 5.0 mA cm−2). Moreover, continuous capacity promotion is observed over 1000 cycles, leading to superior cycling performance (0.444 mAh cm−2 at 1 mA cm−2), with 178% retention after 1000 cycles. This improved cycling performance is attributed to the defective structure and high specific surface area of the VACNTs, which accommodates the volume change of the Fe2O3 particles. In addition, the induced locally graphitization and rearrangement of the carbon layers are demonstrated, which results in better kinetics for Na+ transfer, further enhancing capacity retention over long cycles.

Urchin-like band-matched Fe2O3@In2S3 hybrid as an efficient photocatalyst for CO2 reduction

Herein, an urchin-like Fe2O3@In2S3 hybrid composite is designed and synthesized using a facile process. The composite efficiently harvests light in both the ultraviolet and visible regions, and the unique hierarchical structure provides several advantages for photocatalytic applications: (i) a suitable band-matching structure and broadband-light absorbing capacity enable the reduction of CO2 into hydrocarbon, (ii) the extensive network of interfacial contact between nano-sized Fe2O3 and In2S3 significantly increases the separation of charge carriers and enhances the utilization of photogenerated electron-hole pairs, and (iii) an abundance of surface oxygen vacancies provide numerous active sites for CO2 molecule adsorption. The optimized Fe2O3@In2S3 composite generated CO from the photocatalytic reduction of CO2 at a rate of 42.83 μmol·g−1·h−1, and no signs of deactivation were observed during continued testing for 32 h under 300 W Xe lamp irradiation.

Iron dust explosion characteristics with small amount of nano-sized Fe2O3 and Fe3O4 particles

Iron powder, as one of the most abundant metal fuels that can be used as recyclable carriers of clean energy, is a promising alternative to fossil fuels in a future low-carbon economy. It may pose a potential explosion hazard during the process of processing, storage, transport, and reduction/oxidation (redox). The explosion characteristics of iron dust in air were undertaken via a 20 L spherical explosion chamber with an emphasis on minimum explosion concentration (MEC) of iron dust. The alternative method of combustion duration time (tc) was used to determine MEC and compared with the standardized over pressure method. Two kinds of nano-sized iron oxides (Fe2O3 and Fe3O4) were used as inertants to determine the inhibition effect of different oxidation products. The iron dust explosion products with various shapes and sizes were found to be able to grow up 4–6 times of the iron dust for the first time. Adding small amount of Fe2O3 or Fe3O4 could reduce the explosion severity and sensitivity of iron dust. The MEC data determined by both methods were comparable. The addition of 5 % oxide has obvious inhibition effect under 1500 g/m3 concentration. With the increase of oxide concentration to 10 %, the inerting effect increases, and the MEC of iron dust increases more than 3 times. The increase of dust concentration will weaken the inerting effect. When the concentration increases from 500 g/m3 to 3000 g/m3, the weakening effect of 10 % Fe2O3 on the explosion pressure decreases from 38.45 % to 2.24 %, and 10 % Fe3O4 decreases from 46.21 % to 10.63 %. Unlike coal, biomass or aluminum dusts, the iron dust explosion was found to have a unique secondary acceleration of pressure rise rate for the first time. These results provide a fundamental basis to mitigate the iron dust explosion via solid inerting method without adding extra elements.

Screening of biohydrogen production based on dark fermentation in the presence of nano-sized Fe2O3 doped metal oxide additives

Increasing the biohydrogen production efficiency through the dark fermentation process has become the biggest challenge in recent years. We aim to enhance biohydrogen production yield by adding nano-sized iron oxide doped metal oxides prepared by the wet impregnation method. Biohydrogen production in the presence of additives was evaluated by the screening of (i) type (Fe 2 O 3 @Al 2 O 3 , Fe 2 O 3 @ZrO 2 , and Fe 2 O 3 @TiO 2 ) and (ii) concentration (0–200 mg/L) of additives. During the screening of additive type, approximately 14 wt% nano-sized (6 nm) hematite (Fe 2 O 3 ) doped Al 2 O 3 showed the highest improvement for biohydrogen production yield among all additives. Batch experiments conducted through dark fermentation demonstrated that 50 mg/L Fe 2 O 3 @Al 2 O 3 addition caused an acceleration in biohydrogen production by 34% and an increment in yield by 15%, despite even low concentrations Al 2 O 3 addition inhibited the process. • Hematite doped metal oxides synthesized using hydrothermal methods. • Biohydrogen production activity of Fe 2 O 3 @Al 2 O 3 , Fe 2 O 3 @ZrO 2 , Fe 2 O 3 @TiO 2 were tested. • Buffer solution and concentration selection carried out. • Fe 2 O 3 @Al 2 O 3 showed best enhancement with 15% increment in yield. • 50 mg/L Fe 2 O 3 @Al 2 O 3 accelerated biohydrogen production 34%.

Synthesis of Some Novel Nanosized Chelates of Anchoring Bisazo Dye 5-[5-(4,6-Dioxo-2-thioxo-hexahydro-pyrimidin-5-ylazo)-naphthalen-1-ylazo]-2-mercapto-1H-pyrimidine-4,6-dione and Their Applications as Antioxidant and Antitumor Agents.

A novel bisazo 5-[5-(4,6-dioxo-2-thioxo-hexahydro-pyrimidin-5-ylazo)-naphthalen-1-ylazo]-2-mercapto-1H-pyrimidine-4,6-dione (H4L) ligand has been synthesized from diazotization coupling between naphthalene-1,5-diamine and 2-thiobarbituric acid. Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Fe(III) chelates were prepared. All prepared compounds were characterized by different techniques. The azo groups did not participate in chelation according to the infrared spectra, whereas the thioamide group did participate. The azo dye ligand coordinated with all metallic ions in a neutral–keto–thiol structure and behaved as a bi- and tridentate moiety. Zinc, manganese, and iron chelates had an octahedral structure, while nickel and cobalt chelates had a tetrahedral structure, but the copper chelate had a square pyramidal geometry. The thermal behavior of all prepared compounds was investigated and thermokinetic parameters were also discussed. X-ray diffraction (XRD) data reflected that Fe(III) and Zn(II) complexes were crystalline while the Cu(II) complex was amorphous. Calcination of the Fe(III) complex at 600 °C yielded a nanosized Fe2O3 crystalline phase, elucidated by XRD and transmission electron microscope. The novel azo dye and some of its chelates were tested against HepG-2. The Fe2O3 nanooxide showed remarkable activity against the HepG-2 cell line rather than its precursor Fe(III) complex. Co(II) had a higher antioxidant activity than the other investigated complexes. In both activities, the Cu(II) complex did not show any activity. Molecular modeling and some theoretical studies were validated, and the experimental results were interpreted.

Effects of oxidizer structure on thermal and combustion behavior of Fe2O3/Zr thermite

Performance of MOF-derived micrometer porous Fe2O3 as the oxidizer in Zr-fuelled thermite is compared with commercial nano-sized Fe2O3 by characterizing thermal and combustion behavior of Fe2O3/Zr mixture via differential scanning calorimetry, optical emission measurement as well as composition and morphology analysis on condensed combustion products. Results show that thermal behaviors of Fe2O3/Zr with a slow heating rate have little difference regardless of the kind of Fe2O3. However, MOF-derived micrometer porous Fe2O3 show an obvious superiority in enhancing combustion of Fe2O3/Zr heated by a high rate. Combustion reactions of Fe2O3/Zr under high heating rates are probably rate-controlled by condensed reaction. The better performance of MOF-derived Fe2O3 is attributed to its larger contact area with Zr particle in that micrometer porous Fe2O3 particles are easily broken into primitive nano-sized particles, which effectively avoid the agglomeration of oxidizer. The MOF-derived Fe2O3 particles obtained at calcination temperature of 550 °C enable the best combustion performance of Fe2O3/Zr thermite. This should be because the crystallinity and porous structure of 550 °C-Fe2O3 are more favorable for the mass transfer process during high-rate combustion.

Rational designed structured superhydrophobic iron oxide surface towards sustainable anti-corrosion and self-cleaning

Abstract A hierarchical micro-/nanostructure, consisting of nano-sized Fe2O3 needles vertically grown on the {1 1 1} facets of micro-octahedral Fe3O4 particles, has been successfully prepared on the surface of N80 steel using hydrothermal treatment followed by annealing. The nanoneedles were transformed from nanoparticles on the micro-octahedral facets under the influence of mixed acetone and acetic acid gas atmosphere, and the length of nanoneedles can be controlled by the annealing time. The superhydrophobic Fe2O3/Fe3O4 composite surface with water contact angle (WCA) of 157.3° and sliding angle (SA) of 8.1° was obtained after decorated with stearic acid. The influence of the annealing time on the surface morphology and hydrophobicity was explored and optimized. The superhydrophobic surface displays great self-cleaning and anti-corrosion performances with good mechanical robustness. This method opens a new venue towards preparing micro-nanostructures on the surface of metallic materials for enhanced anti-corrosion and self-cleaning applications.

Nano-sized Fe2O3/Fe3O4 facilitate anaerobic transformation of hexavalent chromium in soil–water systems

The purpose of this study is to investigate the effects of nano-sized or submicro Fe2O3/Fe3O4 on the bioreduction of hexavalent chromium (Cr(VI)) and to evaluate the effects of nano-sized Fe2O3/Fe3O4 on the microbial communities from the anaerobic flooding soil. The results indicated that the net decreases upon Cr(VI) concentration from biotic soil samples amended with nano-sized Fe2O3 (317.1±2.1mg/L) and Fe3O4 (324.0±22.2mg/L) within 21days, which were approximately 2-fold of Cr(VI) concentration released from blank control assays (117.1±5.6mg/L). Furthermore, the results of denaturing gradient gel electrophoresis (DGGE) and high-throughput sequencing indicated a greater variety of microbes within the microbial community in amendments with nano-sized Fe2O3/Fe3O4 than the control assays. Especially, Proteobacteria occupied a predominant status on the phylum level within the indigenous microbial communities from chromium-contaminated soils. Besides, some partial decrease of soluble Cr(VI) in abiotic nano-sized Fe2O3/Fe3O4 amendments was responsible for the adsorption of nano-sized Fe2O3/Fe3O4 to soluble Cr(VI). Hence, the presence of nano-sized Fe2O3/Fe3O4 could largely facilitate the mobilization and biotransformation of Cr(VI) from flooding soils by adsorption and bio-mediated processes.

A comparative study on the electrical and gas sensing properties of thick films prepared with synthesized nano-sized and commercial micro-sized Fe2O3 powders

In this work, Fe2O3 nanoparticles (NPs) were successfully synthesized by Pechini sol-gel method. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction characterizations were used to study the morphology and crystal structure of the synthesized products. The electrical and gas sensing behaviour of the synthesized and commercial Fe2O3 samples, prepared in the form of thick films, were studied. Though the commercial Fe2O3 powders had lower resistance but it was found that the synthesized Fe2O3 NPs had better gas sensing properties. The underlying mechanisms are discussed in details. The present findings show advantages of Fe2O3 NPs over micro-size particles for gas sensing applications.

Heterogeneous photo-Fenton degradation of methyl orange by Fe2O3/TiO2 nanoparticles under visible light

A novel heterogeneous photo-Fenton catalyst Fe2O3/TiO2 nanoparticle was successfully prepared by sol-gel method and characterized by X-ray diffraction (XRD), UV–vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), Photoluminescence spectra (PL) and porosimetry analysis. The characterization results showed that the nano-sized Fe2O3 particles appeared on the TiO2 support and the Fe2O3/TiO2 nanoparticle exhibited enhanced absorption in the broad visible-light region together with an apparent red shift in the optical absorption edge. The XPS results revealed that the presence of Ti4+ and Fe3+ in Fe2O3/TiO2 materials. The activity of heterogeneous photo-Fenton catalyst Fe2O3/TiO2 combined with the photocatalytic and photo-Fenton was assayed in the degradation of methyl orange (MO) in the presence of visible light and H2O2. The results showed that the heterogeneous photo-Fenton was much faster and higher removal of methyl orange than the photocatalytic degradation alone. The mineralization of the organic pollutant was investigated by total organic carbon (TOC) measurements. The Fe2O3/TiO2+H2O2 showed the highest TOC mineralization of MO. All these results indicate the possibility of the practical application of this photocatalyst for water treatment.

Removal of Cu (II) and Pb (II) from aqueous solution using engineered iron oxide nanoparticles

Nano-sized Fe3O4 and Fe2O3 were synthesized using a precipitation method. The nanomaterials were tested as adsorbents for the removal of both Cu2+ and Pb2+ ions. The nanomaterials were characterized using X-ray powder diffraction to determine both the phase and the average grain size of the synthesized nanomaterials. Batch pH studies were performed to determine the optimum binding pH for both the Cu2+ and Pb2+ to the synthesized nanomaterials. The optimum binding was observed to occur at pH4 and above. Time dependency studies for Cu2+ and Pb2+ showed the binding occurred within the first 5min of contact and remained constant up to 2h of contact. Isotherm studies were utilized to determine the binding capacity of each of the nanomaterials for Cu2+ and Pb2+. The binding capacity of Fe3O4 with Cu2+ and Pb2+ was 37.04mg/g and 166.67mg/g, respectively. The binding capacities of the Fe2O3 nanomaterials with Cu2+ and Pb2+ were determined to be 19.61mg/g and 47.62mg/g, respectively. In addition, interference studies showed no significant reduction in the binding of either Cu2+ or Pb2+ to the Fe3O4 or Fe2O3 nanomaterials in the presence of solutions containing the individual ions Na+, K+, Mg2+ and Ca2+ or a solution consisting of a combination of all the aforementioned cations in one solution.

Effect of nanoparticles on froth stability and bubble size distribution in flotation

In order to investigate the usability of nanomaterials as a froth stabiliser in mineral flotation, an experimental study was performed using a froth column and a modified flotation cell. Four different nanomaterials, namely SiO2, TiO2, Fe2O3 and Al2O3, were used in the experiments. The froth column tests were carried out to measure the Sauter-mean bubble size and dynamic froth stability under different operating conditions. Single mineral flotation tests with or without the nanomaterials were performed using a pure barite sample. Results of the froth column tests show that despite of the increasing froth height, the bubble coalescence in the froth or bursting on the surface can be decreased considerably by using the nanomaterials. The effect of the increase in froth height on the Sauter-mean bubble size and the bubble coalescence was found to be negligible by using the nanomaterials in all pH values used. These effects of the nanomaterials could not be attributed to both signs and magnitudes of their surface charges.It was determined that the nanomaterials used in this study did not contribute to the flotation efficiency at shallow froth. Contrary to this, the nanomaterials, in particular nano-sized Fe2O3 and Al2O3, provide a significant increase in barite recovery (7–11%) at deep froth, which means that selection of the type of the nanomaterials to be used in flotation is also important. As a result of the use of the nanomaterial, the decrease in the flotation performance at deep froths was found to be negligible.

Catalytic activity of Fe/ZrO2 nanoparticles for dimethyl sulfide oxidation

A low-temperature vapor phase catalytic oxidation of dimethyl sulfide (DMS) with ozone over nano-sized Fe2O3–ZrO2 catalyst is carried out at temperatures of 50–200°C. Nanostructured Fe2O3–ZrO2 catalyst (FZN) is prepared by modified sol–gel method using citric acid as a chelating agent and conventional FZ catalyst is prepared with co-precipitation method. The catalysts are characterized using N2-BET surface area and pore size distributions, X-ray diffraction, TPR, TPD of DMS and NH3, SEM and TEM. The effects of operating temperature, ozone/DMS concentration and gas hourly space velocity (GHSV) on DMS removal efficiencies via catalytic ozonation are investigated. Relatively higher amount of ozone decomposition is observed on nanocatalyst compared to the co-precipitate catalyst from 50°C to 150°C. In contrast, at 200°C irrespective of the particle size, both catalysts performed similar activity. It clearly demonstrates that under ozone assisted catalytic oxidation over nanocatalyst offers the 100% of DMS conversion at lower temperature. The synthesized nanocatalyst and ozone are observed highly efficient for low temperature catalytic oxidation of DMS. The stability test shows that the nanocatalyst have relatively high activity and stability under the reaction conditions. A plausible reaction mechanism has been proposed for the oxidation of DMS based on the possible reaction products.

Rod-shaped iron oxide nanoparticles are more toxic than sphere-shaped nanoparticles to murine macrophage cells.

Variable sizes of nanoparticles, ranging from nano to micro scale, are of toxicological interest. In the present study, the authors hypothesized that, in addition to the size, the shape of iron oxide (Fe2O3) nanoparticles is a major factor that contributes to particle cytotoxicity. Cytotoxicity to mouse macrophage cells (RAW 264.7) was investigated using 3 different particles: micro-sized Fe2 O3 (M-Fe2O3), nano-sized Fe2O3 (N-Fe2O3), and rod-shaped Fe2O3 (R-Fe2O3). Whereas M-Fe2O3 and N-Fe2O3 were located in the vacuole as aggregates, R-Fe2 O3 was often spread throughout the cytoplasm. The extent of cytotoxicity measured by the water soluble tetrazolium (WST-1) assay was in the order R-Fe2O3 ≈ N-Fe2O3 > M-Fe2O3, whereas the extent revealed by the lactate dehydrogenase assay was in the order R-Fe2O3 >> N-Fe2O3 ≈ M-Fe2 O3. In addition, the degree of tumor necrosis factor-α and reactive oxygen species (ROS) production was in the order of R-Fe2O3 > N-Fe2 O3 > M-Fe2O3. In addition, a much higher extent of necrosis was associated with the presence of R-Fe2O3. These results suggest that the higher degree of necrosis due to R-Fe2O3 is correlated with both the higher degree of membrane damage and ROS production by R-Fe2O3 compared with the results of the other Fe2O3 particles. These results also showed that the degree of cytotoxicity of nanoparticles should be evaluated based on shape as well as size, because changes in shape and size are accompanied by alterations in surface area, which relate closely to cytotoxicity.

Mechanism of combustion catalysis by ferrocene derivatives. 2. Combustion of ammonium perchlorate-Based propellants with ferrocene derivatives

Combustion of mixtures of a narrow fraction of ammonium perchlorate (AP) with hydrocarbon binders and combustion catalysts diethylferrocene and 1,1′-bis(dimethyloctyloxysilyl)ferrocene, as well as nano-sized Fe2O3 is studied. It is shown that the efficiency of ferrocene compounds from the viewpoint of increasing the burning rate depends on the oxidizer/fuel ratio in the propellant and on the place of the leading reaction of combustion. In composites with a high oxidizer/fuel ratio whose combustion follows the gas-phase model, the catalyst efficiency is rather low. In systems with a low oxidizer/fuel ratio where the contribution of condensed-phase reactions to the burning rate of the system is rather large, the catalyst efficiency is noticeably greater, and it is directly related to the possibility of formation of a soot skeleton during combustion. The close values of the catalytic activity of ferrocenes and Fe2O3 in the case of their small concentrations in such compositions testify that the main contribution to the increase in the propellant burning rate is made by Fe2O3 formed due to rapid oxidation of ferrocene on the AP surface and accumulated on the soot skeleton. Thermocouple measurements of propellants with a low oxidizer/fuel ratio are performed, and it is shown that the temperature of their surface is determined by plasticizer evaporation. A phenomenological model of combustion of the examined propellants is proposed.

Pickering-Emulsion-Polymerized Polystyrene/Fe2O3 Composite Particles and Their Magnetoresponsive Characteristics

Core-shell-structured magnetic polystyrene (PS)/inorganic particles were fabricated by Pickering emulsion polymerization using nanosized Fe2O3 particles as a solid stabilizer. Scanning electron microscopy and transmission electron microscopy confirmed the synthesized PS/Fe2O3 particles to be comprised of a PS surface coated with Fe2O3 nanoparticles. The chemical structure of the composite nanospheres was characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The thermal properties of composite nanospheres and corresponding pure polymer were examined by thermogravimetric analysis. The rheological properties of the core-shell-structured magnetic PS/inorganic particles dispersed in silicone oil were investigated under an external magnetic field strength using a rotational rheometer. The particles with extremely lower density than common magnetic particles exhibited solid-like magnetorheological phase characteristics, and the flow curves were fitted to the Cho-Choi-Jhon model of the rheological equation of state.

A facile synthesis of Fe3O4/C composite with high cycle stability as anode material for lithium-ion batteries

Fe3O4/C composites are synthesized by ball milling nano-sized Fe2O3 powder with acetylene black (AB) in different ratios followed by a carbothermal reduction at 600 °C for 6 h. Structural evolution of the Fe2O3/AB mixtures during the carbothermal reduction and the electrochemical properties of the Fe3O4/C composites as anode materials for lithium-ion batteries are investigated. The results show that Fe2O3 has been fully reduced to Fe3O4 during the reduction. The Fe3O4 particles inherit the nano-size feature of Fe2O3 and are well dispersed in the composites. The composites with 60 and 70 wt.%AB additions possess a close capacity of ca. 430 mAh g−1 after 100 cycles, showing retentions of 85% and 95%, respectively. The Fe3O4/C composites converted from Fe2O3/AB mixtures show better electrochemical performance than the mixtures. The favorable electrochemical performance of the Fe3O4/C composites is mainly attributed to the homogeneous distribution of the Fe3O4 nanoparticles in the carbon matrix and the comparatively high electronic conductivity of Fe3O4. The synthesis method is suggested to be facile in large-scale production of superior anode materials for lithium-ion batteries.

FeO/C anode materials of high capacity and cycle stability for lithium-ion batteries synthesized by carbothermal reduction

FeO/C composites are synthesized by carbothermally reducing ball-milled mixtures of nano-sized Fe2O3 and acetylene black (AB) in different ratios. The structure evolution of the mixtures during carbothermal reduction and the electrochemical properties of the reduced products as anode materials for lithium-ion batteries have been investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electrochemical testing. The results show that Fe2O3 is reduced to FeO by AB at 800°C. The FeO particles inherit the nano-size feature of the Fe2O3 particles and well disperse in the composites. The FeO/C composites possess capacity retentions higher than 96% after 50 cycles when the AB additions reach 50wt.%. The FeO/C composite with 50wt.% AB addition shows a superior capacity of 510mAh/g after 50 cycles, which is much higher than that of the Fe2O3/50wt.% AB mixture, which is 400mAh/g. The flexible structure and high electronic conductivity of AB, the comparatively high electronic conductivity of FeO all play effective roles in improving the electrochemical properties of the FeO/C composites. 50wt.% is a recommended content for the addition of AB. Too high content of AB lowers the capacity of the FeO/C composites due to the low capacity nature of AB. The synthesis method is considerably facile for large-scale production.

Nanoparticle Fe2O3-Loaded Carbon Nanofibers as Iron-Air Battery Anodes

We prepared nanoparticle Fe2O3-loaded carbon nanofiber material by a chemical method. Fe(NO3)3 was impregnated on carbon in an aqueous solution, and the mixture was dried and then calcined for 1 h at 400°C in flowing Ar. The herringbone carbon nanofiber and mesoporous carbon nanofiber with large actual surface area were used to increase the dispersion of iron on the carbon surface. Transmission electron microscopy (TEM) coupled with X-ray diffraction measurements revealed that nano-sized Fe2O3 particles were distributed on the carbon surface and that many nano-sized Fe2O3 species were present inside the pores on the mesoporous carbon surface. Such dispersion of nano-sized Fe2O3 will support the redox reaction of iron and result in improved capacity of Fe2O3-loaded carbon electrodes.