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Magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods were successfully prepared via calcination reduction process using glucose as reductant, and they were characterized by SEM, TEM, XRD and VSM techniques. The influences of additive concentration, solution volume, reaction temperature and reaction time on morphology and the properties of Fe3O4/α-Fe2O3 heterogeneous nanorods were investigated. Firstly, α-Fe2O3 nanorods were prepared by the hydrothermal approach, and the FeCl3 concentration of 20 mM, the NH4H2PO4 concentration of 0.96 mM, the hydrothermal volume of 60 mL, the hydrothermal temperature of 180 °C, and hydrothermal time of 12 h were selected as the optimum conditions. Secondly, magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods calcined at 600 °C for 3 h with the mass ratio of 1:20 for α-Fe2O3 nanorods and glucose were constructed with largest saturation magnetization of 78.2 emu/g, their average length and average diameter were about 215.0 nm and 79.2 nm, respectively. An optimization process for the fabrication of magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods was introduced in this paper. Thereinto, α-Fe2O3 nanorods as a precursor were fabricated by hydrothermal method, and using glucose as a reduction agent to prepare the results products by high-temperature calcination. The influences of FeCl3 concentrations, NH4H2PO4 concentration, solution volume, hydrothermal temperature, hydrothermal time and the ratio of the precursors and glucose on the morphologies and magnetic properties of α-Fe2O3 and magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods were investigated, and their influence rules were revealed. [ABSTRACT FROM AUTHOR]

New and efficient sensors of nerve agents are urgently demanded to prevent them from causing mass casualties in war or terrorist attacks. So, in this work, a novel hierarchical nanoheterostructure was synthesized via the direct growth of α-Fe2O3 nanorods onto multiwall carbon nanotube (MWCNT) backbones. Then, the composites were functionalized with hexafluoroisopropanol (HFIP) and successfully applied to detect dimethyl methylphosphonate (DMMP)-sarin simulant gas. The observations show that the HFIP-α-Fe2O3@MWCNT hybrids exhibit outstanding DMMP-sensing performance, including low operating temperature (220 °C), high response (6.0 to 0.1 ppm DMMP), short response/recovery time (8.7 s/11.9 s), as well as low detection limit (63.92 ppb). The analysis of the sensing mechanism demonstrates that the perfect sensing performance is mainly due to the synergistic effect of the chemical interaction of DMMP with the heterostructure and the physical adsorption of DMMP by hydrogen bonds with HFIP that are grafted on the α-Fe2O3@MWCNTs composite. The huge specific surface area of HFIP-α-Fe2O3@MWCNTs composite is also one of the reasons for this enhanced performance. This work not only offers a promising and effective method for synthesizing sensitive materials for high-performance gas sensors but also provides insight into the sensing mechanism of DMMP. [ABSTRACT FROM AUTHOR]

The ultrasmall Ag species decorated on α‐Fe2O3 nanorods photocatalysts are prepared through a facile in situ photodeposition process. The obtained Ag/α‐Fe2O3 composite samples display more outstanding photocatalytic activity than original α‐Fe2O3 in the degradation of tetracycline hydrochloride (TC‐HCl) in water. The degradation rate constant of TC‐HCl over the Ag/α‐Fe2O3‐5 sample reaches up to 0.0118 min−1, which is about 6.21 times than that over original α‐Fe2O3 sample (0.0019 min−1). The structure characterizations, physicochemical properties, and photoelectrochemical measurements reveal that the visible light absorption ability and charge separation efficiency are improved dramatically owing to the decoration effect of ultrasmall Ag species on the surface of α‐Fe2O3 nanorods. The photocatalytic reaction mechanism investigations demonstrate that holes, ˙O2−, and ˙OH all are main active species and play important roles in the degradation process of TC‐HCl. [ABSTRACT FROM AUTHOR]

• Superstructured α-Fe 2 O 3 nanorods grown on the CNTF as binder-free negative electrode. • Array of 3D nanoplates architectures formed the superstructured α-Fe 2 O 3 nanorods. • Superstructures with empty place and channels reduced ion transport distance. • The FESD exhibits outstanding electrochemical performance and excellent weavability. Fiber-shaped energy storage devices are indispensable parts of wearable and portable electronics. Aqueous rechargeable Ni/Fe battery is a very appropriate energy storage device due to their good safety without organic electrolytes, high ionic conductivity, and low cost. Unfortunately, the low energy density, poor power density and cycling performance hinder its further practical applications. In this study, in order to obtain high performance negative iron-based material, we first synthesized α-iron oxide (α-Fe 2 O 3) nanorods (NRs) with superstructures on the surface of highly conductive carbon nanotube fibers (CNTFs), then electrically conductive polypyrrole (PPy) was coated to enhance the electron, ion diffusion and cycle stability. The as-prepared α-Fe 2 O 3 @PPy NRs/CNTF electrode shows a high specific capacity of 0.62 Ah cm−3 at the current density of 1 A cm−3. Furthermore, the Ni/Fe battery that was assembled by the above negative electrode shows a maximum volumetric energy density of 15.47 mWh cm−3 with 228.2 mW cm−3 at a current density of 1 A cm−3. The cycling durability and mechanical flexibility of the Ni/Fe battery were tested, which show good prospect for practical application. In summary, these merits make it possible for our Ni/Fe battery to have practical applications in next generation flexible energy storage devices. [ABSTRACT FROM AUTHOR]

Wearable biosensors are potential game changers in the field of non-invasive diagnosis of fatal diseases. They require advancements in designing flexible and textile-based sensor platforms. Herein, a stable, and selective electrochemical sensing platform based on conductive carbon cloth yarn (CCY) supported α-Fe 2 O 3 nanorods for interleukin-6 (IL-6) detection was developed successfully. Well-defined vertical growth of α-Fe 2 O 3 nanorods on CCY was achieved via a facile hydrothermal approach. The α-Fe 2 O 3 /CCY platform was adapted as a label-free immunosensor electrode by conjugating anti-IL-6 antibodies. Upon exposure to different concentrations of IL-6 (1 pg/ml to 100 ng/ml), the sensor showed a linear current variation response and a low detection limit of 0.26 pg/ml. The improved electronic conductivity and active surface area due to the integration of α-Fe 2 O 3 onto CCY has resulted in better performance of the immunosensor electrode, as revealed by the electrochemical characterization. The immunosensor showed a selective response towards IL-6, even in the presence of interfering compounds, and showed exceptional operational stability along with shelf-life stability. The immunosensor exhibited reproducible results, which makes it a suitable candidate for developing fabric-based wearable sensors. [Display omitted] • A novel flexible sensing platform for label-free electrochemical IL-6 detection. • The constructed immunosensor showed high sensitivity and selectivity towards IL-6. • A low detection limit of 0.26 pg/ml with good linearity. [ABSTRACT FROM AUTHOR]

Indium Tin Oxide (ITO) conductive glass was modified by layer-by-layer modification of chitosan (CS) and α-Fe2O3 nanoparticles. Lactic acid bacteria were the source of electrons in the studied microbial fuel cells (MFCs) system. When ITO/(CS/α-Fe2O3)4/CS was the anode, external resistance was 626.6 Ω, while maximum current and maximum power density were 1.16 mA and 0.122 W/m2, respectively. These values were far higher than already reported results. Atomic force microscope image proved that ITO/(CS/α-Fe2O3)4/CS surface was rougher than blank ITO and ITO/(CS/α-Fe2O3)8/CS surfaces, which enable it to have a higher specific surface area for the microbes to grow. For ITO/(CS/α-Fe2O3)4/CS, physical properties played a leading role, while the chemical properties mainly determined the surface morphology of ITO/(CS/α-Fe2O3)8/CS. Lactic acid bacteria in fermentation waste could improve the current of MFCs. Layer-by-layer assembly of CS/α-Fe2O3 could significantly improve the performance of MFCs. [ABSTRACT FROM AUTHOR]

The development of simple and reproducible synthesis techniques for obtaining one-dimensional semiconducting nanostructures is essential for the advancement of gas sensor devices. We report a facile and versatile approach for the in-situ growth of vertically oriented hematite nanorods to be applied as a resistive ozone gas sensor. The α-Fe 2 O 3 nanorods were grown via a hydrothermal treatment directly onto an Al 2 O 3 substrate with interdigitated Pt electrodes, thus facilitating the integration of nanorods into the sensing platform. At 150 °C, the gas-sensing experiments revealed a good sensitivity of these nanorods to different ozone concentrations (10–570 ppb), besides a fast response time and repeatable response–recovery cycles. The present study offers a promising way for designing high-performance gas sensors based on hematite nanorods. [Display omitted] • Ozone gas sensor based on hematite obtained via a facile approach. • Hematite nanorods grown via a hydrothermal route directly onto the sensing platform. • Nanorods exhibited a good sensitivity and fast response to sub-ppm O 3 level. [ABSTRACT FROM AUTHOR]

Abstract: A novel Fe2O3/carbon composite is prepared using a facile one-step hydrothermal method. Its structure, morphology and performance as anode of lithium ion battery are investigated with X-ray diffraction, scanning electron microscopy, thermogravimetry, cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. It is found that the as-prepared composite is composed of α-Fe2O3 nanorods of about 75 nm in diameter and 1 μm in length, which are enwrapped with soft and curly carbon nanofibers, and exhibits superior charge/discharge performance compared to bare α-Fe2O3 nanorods, especially at high current rate. The discharge capacity is 1069 mAh g−1 at the first cycle and remains 560 mAh g−1 after 30 cycles at 0.2C for the bare nanorods, but improved to 1278 mAh g−1 and 960 mAh g−1 for the composite. At 12C, the discharge capacity is only 798 mAh g−1 initially and becomes 98 mAh g−1 after 30 cycles for the bare nanorods, while 844 mAh g−1 and 292 mAh g−1 for the composite. The improved performance of the composite is attributed to the bondage from carbon nanofibers, which contributes to the improvement in electronic conductivity and structure stability of α-Fe2O3 nanorods. [Copyright &y& Elsevier]

Abstract: The catalytic properties of cubiform Co3O4 nanoparticles, α-Fe2O3 nanorods, and NiO nanoparticles were studied using both microarray method and FI-CL method. These nanoarticles exhibit high specific catalytic effects on the chemiluminescence (CL) reaction of the luminol–H2O2 system in alkaline solution compared with other common catalysts. A reaction mechanism is described. It provides new insights into the application of nanoparticle materials. The CL method based on the use of the Co3O4 nanoparticles is ultrasensitive and particularly selective. Therefore, it was applied to the analysis of H2O2 which can be determined in the concentration range from 1.0nM to 1000nM, with a detection limit of 0.3nM. The relative standard deviation is 2.1% at 0.1μM of H2O2 (for n =11). The method was successfully applied to the determination of trace quantities of H2O2 in exhaled breath condensate (EBC) where it is a mediator of oxidative stress and a promising biomarker for diagnosing. The assay requires a small sample and no incubation time, and has an analytical runtime of <1min. It is timesaving and suitable for larger studies. The levels of H2O2 in EBC are found to be elevated in healthy subjects (average=0.54nM), rheum subjects (average=0.24nM), and feverish subjects (average=0.16nM). Our data suggested that the average H2O2 concentration of EBC from feverish subjects was significantly higher than healthy subjects and rheumatic subjects. [Copyright &y& Elsevier]

Abstract: The α-Fe2O3 nanorods were successfully synthesized without any templates by calcining the α-FeOOH precursor in air at 300°C for 2h and their LPG sensing characteristics were investigated. The α-FeOOH precursor was prepared through a simple and low cost wet chemical route at low temperature (40°C) using FeSO4·7H2O and CH3COONa as starting materials. The formation of α-FeOOH precursor and its topotactic transformation to α-Fe2O3 upon calcination was confirmed by X-ray diffraction measurement (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. The α-Fe2O3 nanorods exhibited outstanding gas sensing characteristics such as, higher gas response (∼1746–50ppm LPG at 300°C), extremely rapid response (∼3–4s), relatively slow recovery (∼8–9min), excellent repeatability, good selectivity and lower operating temperature (∼300°C). Furthermore, the α-Fe2O3 nanorods are able to detect up to 5ppm for LPG with reasonable response (∼15) at the operating temperature of 300°C and they can be reliably used to monitor the concentration of LPG over the range (5–60ppm). The experimental results clearly demonstrate the potential of using the α-Fe2O3 nanorods as sensing material in the fabrication of LPG sensors. Plausible LP G sensing mechanism of the α-Fe2O3 nanorods is also discussed. [Copyright &y& Elsevier]

Abstract: α-Fe2O3 nanorods were synthesized by a facile hydrothermal method. The as-prepared α-Fe2O3 nanorods have a high quality crystalline nanostructure with diameters in the range of 60–80nm and lengths extending from 300 to 500nm. The crystal structure of the α-Fe2O3 nanorods was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The α-Fe2O3 nanorod anodes exhibit a stable specific capacity of 800mAh/g. This indicates significantly improved electrochemical performance in lithium-ion cells, compared to that of commercial microcrystalline α-Fe2O3 powders. [Copyright &y& Elsevier]

Abstract: Alpha iron oxide (α-Fe2O3) films were grown on catalyst-free silicon substrate using a vertical type metal–organic chemical vapor deposition process. X-ray powder diffraction and field-emission transmission electron microscopy measurements showed that these α-Fe2O3 films consisted of bundles of one dimensional (1D) nanorods and the nanorods in these α-Fe2O3 films were single crystalline with a well-ordered rhombohedral structure. The nanorods showed a preferred growth orientation in the [104] direction. Magnetic force microscopy image suggests that spin domains were formed in the α-Fe2O3 nanorods. Photo-catalytic property of these nanorod films was confirmed through the photo-degradation of Rhodamine B by UV irradiation. These α-Fe2O3 film/nanorod materials could be used as building blocks for nanodevice applications. [Copyright &y& Elsevier]

Abstract: α-Fe2O3 nanorods were incorporated into poly(methyl methacrylate) (PMMA) by in situ radical polymerisation of methyl methacrylate initiated by 2,2′-azobisisobutyronitrile. The α-Fe2O3 nanorods were synthesized by forced hydrolysis of FeCl3 and structural characterization was performed by X-ray diffraction and transmission electron microscopy. The molar mass and the polydispersity index of synthesized PMMA samples were determined by gel permeation chromatography. The content of residual monomer was determined by 1H NMR spectroscopy. The influence of α-Fe2O3 nanorods on the thermal stability of the polymer was investigated using thermogravimetry and differential scanning calorimetry. The molar mass and polydispersity index of PMMA were dependent on the content of α-Fe2O3 nanorods. The values of the glass transition temperature of the nanocomposites were lower compared to pure PMMA. Also, the thermal stability of nanocomposites in nitrogen and air was different from that of pure PMMA. [Copyright &y& Elsevier]

α-Fe2O3 fusiform nanorods were prepared by a simple hydrothermal method employing the mixture of FeCl3·6H2O and urea as raw materials. The samples were examined by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV–vis diffuse reflectance spectra (UV–DRS). Its visible-light photocatalytic performances were evaluated by photocatalytic decolorization methylene blue (MB) in visible light irradiation. It was found that pure phase α-Fe2O3 nanorods with a length of about 125 nm and a diameter of 50 nm were successfully synthesized. The photocatalytic decolorization of MB results indicated that α-Fe2O3 nanorods showed higher photocatalytic activity than that of commercial Fe2O3 nanoparticles—these are attributed to its unique three-dimensional structure and lower electron-hole recombination rate. [ABSTRACT FROM AUTHOR]