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Spray pyrolysis at various temperatures was employed to produce non-crystalline and crystalline iron oxide (α-Fe 2 O 3) thin films on glass. The amorphous and crystalline characteristics of α-Fe 2 O 3 thin films were affirmed via X-ray diffraction analysis. With low deposition times (5 min) and at various substrate temperatures, iron oxide seems almost in a non-crystalline structure. As for the increase in deposition time (40 min), the crystallinity's degree was enhanced. According to Tauc's law, the direct gap energy E d for both the amorphous and the crystalline phases, were found to be 1.95 and 2.125 eV, respectively. Moreover, the indirect gap energy, E in = 1.65 and 1.71 eV were obtained for the amorphous phases and the crystalline phases, respectively. The linear and non-linear optical features of amorphous and crystalline structure were meticulously and adaptably detailed. It is observed that the behavior of the refractive index n (λ) and extinction coefficient k (λ) of the crystalline state was lower than that of the amorphous state. The real and imaginary linear dielectric constant and also the thin film quality factor were estimated for both the amorphous and crystalline states as well as the volume and surface energy loss functions for the crystalline and amorphous states. In conclusion, amorphous and crystalline α-Fe 2 O 3 nanocrystalline films improved their optical properties, making them potential candidates for multifunctional applications such as optoelectronics and spintronics electronics devices. [ABSTRACT FROM AUTHOR]

• Experiments are performed in both CSS and MSS at different water depths in coated and uncoated absorber. • Increase in water depth decreases the fresh water generation from both cases. • The fresh water produced from CSS and MSS are 3.85 and 6.03 kg/m2 respectively. • The thermal and exergy efficiencies are found as 47.67 and 4.53 % respectively using the MSS. • CPL of fresh water produced is lowered by 29.96 % than the SS using uncoated absorber. The quantity of drinkable water that is easily accessible is dwindling at an extremely quick pace. An extra degree of complication has been added to the problem as a consequence of the depletion of freshwater resources brought on by human activities. The primary objective of the present study is to enhance the rate of fresh water generation through the low-cost solar desalination unit using iron oxide as coating material using different thickness of water placed in the absorber plate. The experimental results revealed that the influence of metal oxide nanoparticle as absorber coating material improved the rate of fresh water generation by 36.08 % than the conventional solar still at a minimum thickness of water as 1 cm in the absorber. The palatable fresh water generated from the SS without any absorber coating for the thickness of water as 10, 20 and 30 mm is found to be 3.85, 3.09 and 2.90 kg/m2 respectively. However, with effective coating of the absorber plate using Fe 2 O 3 nanoparticle, the cumulative daily palatable water generated from the solar still for different thickness of water as 10, 20 and 30 mm is enhanced to about 6.03, 5.36 and 4.72 kg/m2 respectively. There is a significant enhancement of about 38.47 to 60.15 % and 1.96 to 4.53 % in the daily energy, and exergy efficiencies of the solar still using coated absorber plate in the SS respectively while compared to the SS using uncoated absorber at the lowest thickness of water in the absorber of basin. Similarly, the CPL of fresh water produced from the SS using coated absorber is lowered by 29.96 % than the SS using uncoated absorber. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, eco-friendly and magnetic sucrose-derived Fe-containing mesoporous carbon (Fe-MC) composites have been prepared by carbothermal reduction. The Fe-MC3-1000 prepared from sucrose and FeSO 4 with a mass ratio of 1:1 at 1000 °C has a uniform mesoporous structure with a BET surface area of 184 m2/g. The carbothermal reduction of Fe 2 O 3 had dual effects of the pore-forming and the loading. Batch adsorption experiments and electrochemical measurements show that the Fe-MC3-1000 has the optimum performance in both adsorption and supercapacitor applications. For adsorption, the maximum adsorption capacity for Congo red (CR) arrived at 972.1 mg g−1 with a removal percentage of 97.2 %. The adsorption process has good agreement with Langmuir isotherm and Elovich kinetic models. Besides, the Fe-MC3-1000 exhibits good recyclability after five adsorption-desorption cycles. For supercapacitor, the Fe-MC3-1000 electrode has a capacitance value of 179.23 F g−1 and a capacitance retention of 92.8 % at 10 A g−1 after 2000 cycles. The outstanding adsorption and electrochemical performances suggest that the Fe-MC3-1000 is a competitive bi-functional material for adsorption and supercapacitor. [Display omitted] • Magnetic Fe-containing mesoporous carbon was prepared via carbothermal reaction. • Low cost and eco-friendly raw materials promote its economy and sustainablity. • The carbothermal reduction of Fe 2 O 3 had dual effects of pore-forming and loading. • Both high adsorption capacities and removal percentages for CR were achieved. • The Fe-MC3-1000 had good electrochemical performance at a high current density. [ABSTRACT FROM AUTHOR]

Drinking of water polluted with heavy metals is a means by which heavy metals bio accumulate in the human body. The rise in galamsey (illegal mining) activities in Ghana has resulted in heavy metal pollution in most water bodies in the country. Above the permissible limits, these metals cause health issues such as cancer, brain damage, kidney damage and other respiratory diseases. Hence, a smart solution to this menace is urgently needed. In this study, iron oxides were recovered from cupola furnace slag by magnetic separation and froth flotation. The recovered iron oxide was modified using electrospinning with the aid of polyvinyl alcohol after which it was calcined and used as adsorbent to detoxify lead and arsenic from two galamsey polluted water bodies in Obuasi, Ghana. Samples of the adsorbent were characterized using X-ray Fluorescence (XRF), X-ray Diffractometry (XRD), Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscopy (SEM) and Brunauer-Emmer-Teller (BET) method. The highest recovery for iron oxide using magnetic separation was 99.42% and that of froth flotation was 90.64%. The recovered iron oxide used as adsorbent was composed 53.04% iron oxide, with major phases like magnetite, hematite, goethite and quartz. Moreover, the surface functional group were determined to be Fe–O and OH. Also, the calcined nano fibres which were spherical in shape with rough surfaces had a specific surface area of 1.1331 m2/g. The contaminated and detoxified water were also analyzed using Atomic absorption Spectroscopy (AAS). Both adsorbent (beneficiated iron oxide and calcined nano fibre) performed well in the adsorption process, with the recovered iron oxide having 97.33% maximum lead removal efficiency while an 81.00% maximum removal efficiency for arsenic. The calcined nano fibre had a maximum of 99.99% removal efficiency for lead and 88.40% maximum efficiency for arsenic. Additionally, the adsorption fits the Langmuirian isotherm model better than the Freundlich model, indicating mono layer coverage. • Cupola furnace slags are rich in iron oxides and can be recovered for various application. • Magnetic separation and froth flotation were used to recover the iron oxides from the cupola furnace slag. • The recovered iron oxides (Fe 3 O 4 , α -Fe 2 O 3 , FeO 2 H and γ -Fe 2 O 3) were used for lead and arsenic adsorption. • The iron oxides achieved high removal efficiency for the heavy metals (Pb and As). [ABSTRACT FROM AUTHOR]

[Display omitted] • Pigment adsorption onto iron oxides is mainly due to electrostatic attraction. • The pigment-binding capacity is in the order of ferrihydrite > goethite > hematite. • The affinity of iron oxide towards pigment is in the sequence of AR > TA > BB. • Different mechanisms involved in pigment adsorption vary with pH values. • Pigments and Cu2+ have a mutual promotion effect on their adsorption. The knowledge about the adsorption properties of pigments onto different iron oxide minerals is still limited. The adsorption behaviors of three typical pigments, including amaranth (AR), tartrazine (TA), and brilliant blue (BB), onto three iron oxides (ferrihydrite, goethite, and hematite) were investigated. The primary mechanism of their interactions was the electrostatic attraction. The affinities of iron oxides toward any pigment were generally in the sequence of ferrihydrite > goethite > hematite (e.g., the maximum adsorption amounts (q max) of AR onto the three iron oxides were 35.5 mg/g, 11.6 mg/g, and 4.2 mg/g, respectively), which was related to the differences in physicochemical properties of minerals (e.g., specific surface area, surface hydroxyl density, and crystal structure). Interestingly, for a given iron oxide, the pigment-binding capacity of the mineral was in the order of AR > TA > BB. This effect was attributed to variations in pigment molecular sizes and electrostatic interactions between pigments and minerals. The pigment-binding capabilities of iron oxides changed as the solution pH varied. Hydrogen-bonding and electrostatic interactions were the main mechanisms below and above pH > pH PZC (pH value at zero point charge), respectively. Furthermore, adding Cu2+ facilitated pigment adsorption, mainly stemming from the surface-bridging effect. Pigments also enhanced Cu2+ adsorption onto iron oxides due to the decreasing electrostatic repulsion between Cu2+ and particles as well as the complexion between Cu2+ with pigment molecules adsorbed on mineral surfaces. The insightful information demonstrates that ubiquitous iron oxide minerals can affect the fate of pigments in natural environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • T. indica fruit extract-based Fe 2 O 3 NPs (T. indica -Fe 2 O 3 NPs) were synthesized and characterized. • T. indica -Fe 2 O 3 NPs have shown significant antibacterial effects. • T. indica -Fe 2 O 3 NPs have shown significant antibiofilm effects. • T. indica -Fe 2 O 3 NPs have shown DPPH radical scavenging activity. In this investigation, T. indica fruit extract was used to phyto-synthesize T. indica -Fe 2 O 3 NPs and then they were characterized by bio-physical techniques. The formation of T. indica -Fe 2 O 3 NPs was checked by the development of black colour precipitate. A sharp peak was noticed at 400 nm for T. indica -Fe 2 O 3 NPs by UV–Vis spectroscopy. The different XRD peaks denotes the hexagonal shape of T. indica -Fe 2 O 3 NPs and the size of crystallite was 19.8 nm. The role of phytochemicals in the plant extract during NPs synthesis was confirmed by FTIR spectra. The existence of polyhedral shaped NPs measuring 28 nm was noticed through SEM analysis. EDX spectra recorded the weight (%) of elemental iron was 77.91%. The agar well diffusion assay revealed that the prepared T. indica -Fe 2 O 3 NPs showed greater inhibition of E. faecalis and S. aureus (Gram-positive) than K. pneumoniae and E. coli (Gram-negative) at 25 to 100 µg mL−1. Biofilm inhibition of test bacteria and fungi was noted. DPPH scavenging was increased to 71.1% at 100 μg mL−1. This investigation arrives the fact that T. indica -Fe 2 O 3 NPs has the potential to treat bacterial infections and could be employed as a substitute to conventional therapeutic agent in biomedical sector in the future. [ABSTRACT FROM AUTHOR]

Liquid lead–bismuth eutectic (LBE) is a heavy metal alloy with great potential as a coolant and spallation target material for Generation IV nuclear reactors. For LBE technology to be widely accepted as reliable, a comprehensive understanding of LBE coolant chemistry is crucial. Specifically, precise determination of chemical interactions between corrosion products and dissolved oxygen in LBE is essential. For that purpose, the thermal cycling method is used in the present research, in which a well-controlled batch of LBE is repeatedly cooled while a potentiometric oxygen sensor monitors the dissolved oxygen concentration. According to the literature, magnetite ( Fe 3 O 4 ) is confirmed to be an important oxide to describe oxygen–iron interaction in LBE. However, thermal cycling experiments indicate the presence of another oxide, besides Fe 3 O 4 , participating in LBE bulk chemistry under conditions relevant for LBE-cooled reactors (200 °C–400 °C, 1 0 − 8 wt.%– 1 0 − 5 wt.% dissolved oxygen concentration). By varying iron impurity content, nickel impurity content and cooling rate in the experiments, the oxide has been identified as hematite ( Fe 2 O 3 ). Thermodynamic equilibrium calculations show that Fe 2 O 3 formation through the reaction of Fe 3 O 4 with dissolved oxygen can explain the observed oxygen trends. As Fe 2 O 3 could form during LBE cooling, an oxygen control strategy should take into account additional oxygen consumption in the reactor cold leg. [Display omitted] • As-received liquid lead–bismuth eutectic is studied by cycling temperature. • Electrochemical oxygen sensor measures the dissolved oxygen concentration in-situ. • A new oxide is found in the bulk near the oxygen saturation limit at 200 – 400 ° C. • Addition of nickel and iron reveals the oxide is hematite forming from magnetite. • A correlation is derived to calculate the oxide's equilibrium from JANAF database. [ABSTRACT FROM AUTHOR]

Atomic-scale wear, behaving distinctly from macroscale wear, has been gaining significant scientific interest. We previously proposed a semi-empirical wear model for covalent bonding materials, which primarily describes an interfacial-bond-dominant atomic-scale wear process. To assess the model's broader applicability on other material types, herein we selected the iron oxide (Fe 2 O 3) as a representative ionic bonding material and conducted the large-scale atomistic simulations. The simulations unveiled two main atomic-scale wear mechanisms of Fe 2 O 3 : plastic deformation/cracking of nano-asperities induced by the asperity collision, and atom-by-atom attrition caused by the interfacial O–Fe bond formation. Crucially, our simulations proved effective in capturing the atom-by-atom attrition wear, thus confirming its validity for ionic materials and expanding its potential usefulness to a broader range of materials. [ABSTRACT FROM AUTHOR]

Phosphorus (P) removal from freshwater bodies to ultra-low concentrations is fundamental to prevent eutrophication, while its recovery is necessary to close the P usage cycle. Iron oxide-based adsorbents seem promising candidates, being abundant, cheap, and easy to synthesize compounds, with good affinity for P. Affinity is the key parameter when targeting ultra-low concentrations. Also, adsorbent regeneration and re-use is fundamental for the economic viability, hence the adsorbent stability is important. Goethite, (α-FeOOH), is one of the most stable iron (Fe3+) (hydr)oxide species, with higher affinity, but lower adsorption capacity (per kg) compared to other species. Doping could change goethite surface properties, to boost the adsorption capacity, while preserving the high stability and affinity for P. In this work, pure goethite was compared to goethite doped (5%at.) with different elements of different preferential oxidation states: Zn2+, Mn3+, and Zr4+. Doping was successfully achieved for all elements, albeit Zr showed a lower Fe substitution than targeted. Zn doping increased the goethite point of zero charge and adsorption capacity (per mass and per surface area), preserving the high affinity, while Mn- and Zr- doping displayed a decrease in all the parameters. These could be explained with surface protonation as a charge compensation mechanism in Zn2+-for-Fe3+ substitution. The regeneration test showed improved P recovery for Zr- and Zn-doped goethite. All samples remained stable throughout the whole process. This work provides promising insights on doping as a strategy to manipulate iron oxides surface properties and for developing a highly performing and long-lasting goethite-based adsorbent. [Display omitted] • Three different elements with different oxidation states were used as dopants for goethite: Zn2+, Mn3+, Zr4+. • Zn-doped goethite showed the highest point of zero charge and P adsorption. • Zr doping of goethite, which has never been attempted before, was successful. • Mn- and Zr-doped goethite displayed a decrease in P adsorption performances. • Charge compensation mechanism during doping interesting for adsorbent development. [ABSTRACT FROM AUTHOR]

In this paper, Cu and Fe dispersion states over Ce0.1Al were modified by different doping methods such as impregnation and co-precipitation. Cu and Fe were dispersed on the surface of Ce0.1Al carriers in Cu/Fe/Ce0.1Al sample, while for Cu/FeCe0.1Al catalyst, Fe was doped in the carriers and Cu was uniformly dispersed on the surface. The effects of dispersion states on the catalytic behaviors of NO reduction by CO were investigated. The resistance to O 2 and SO 2 was also verified. Cu/FeCe0.1Al catalyst owned superior denitrification activity and O 2 /SO 2 -tolerance performance than Cu/Fe/Ce0.1Al. For the front one, Fe was introduced by co-precipitation scheme. Small particle size and higher specific surface area was achieved. Thus its redox and adsorption performance were ameliorated. For the latter, more active species were enriched on the surface, which was conductive to the defects formation and the reduction of surface adsorbed oxygen. In combination with microstructure characterizations, the intrinsic mechanism was proposed. In essences, the interaction among Cu, Fe and Ce was modified owing to their different dispersion state of Cu and Fe. As a result, NO+CO reaction followed different mechanism over two catalysts. NO reduction by CO on Cu/Fe/Ce0.1Al catalyst followed E-R mechanism, while L-H mechanism was dominant over Cu/FeCe0.1Al catalyst. • Cu and Fe dispersion states over Ce0.1Al were modified by impregnation and co-precipitation. • Cu/FeCe0.1Al catalyst exhibited the optimal performance in 250–650 °C, and superior resistance to O 2 and SO 2. • The effects of different modification methods on the structure, physical-chemical properties of catalysts were analyzed and compared by various characterizations. • The CO+NO reaction mechanism over catalysts with different preparation methods were investigated. • Moderate defects were conducive to improve catalytic activity, while excessive defects might inhibit NO catalytic reduction by CO. [ABSTRACT FROM AUTHOR]

[Display omitted] Spray solution combustion synthesis is proposed as a onestep method for preparation of nanostructured iron oxide–silver patchy particles for polyfunctional applications. [ABSTRACT FROM AUTHOR]

Li-rich layered cathode materials have received wide attention due to their superior Li-storage capability. However, their applications are still limited by capacity degradation and voltage decay, which is caused by the phase transition and metal dissolution during repeated cycling. In this work, iron oxide (FeO x) atomic layer deposition (ALD) was performed on Li-rich layered cathode powders in a fluidized bed reactor, followed by an annealing process to further improve their electrochemical performance. After 100 cycles of charge-discharge at 55 °C and 1C (1C = 250 mA g−1), the cathode made from particles with 40 cycles of FeO x ALD and annealing showed a 73% retention of the initial capacity (221 mAh g−1), while the electrode made from the pristine powders showed only 26% retention of the initial capacity (197 mAh g−1) at the same conditions. The enhancement of Li+ transport and cyclic stability stemmed from a stable Fe-doped spinel phase on the surface of cathode particles after ALD coating followed by annealing. A detailed post-test analysis demonstrated that the modification limited impedance growth and suppressed electrolyte degradation and metal dissolution. Image 1 • Combining ALD and annealing resulted in Fe subsurface-doping in LRNMC particles. • The Fe-doped spinel phase improved surface stability and suppressed side reactions. • The Li+ transport was improved by surface modification, resulting in a higher capacity. [ABSTRACT FROM AUTHOR]

• Iron oxide with variable quantities of Feδ+ and SO 4 2− mediated by temperatures of SO 2 mixed with O 2. • Iron oxide with surface Feδ+ (δ ≤ 2) functioning as H 2 O 2 activators to form aqueous OH. • Iron oxide with SO 4 2− functionalities converted to surface SO 4 •- via radical transfer from aqueous OH. • Iron oxide with SO 4 − species used to degrade aqueous pollutants via heterogeneous catalysis. • Iron oxide with SO 4 − species acting as recyclable crackers of aqueous contaminants. OH or SO 4 − are powerful oxidants that efficiently degrade recalcitrant contaminants. The productions of OH and SO 4 − via activation of their precursors (H 2 O 2 and Na 2 S 2 O 8), however, can be sustainable only after continuously feeding such precursors into the activators. Motivated by the advantages of SO 4 − over OH as an environmental cracker, this study highlighted a simple and proficient way to persist solid-supported SO 4 − species used to accelerate the decomposition of recalcitrants in the presence of an electric potential. While using ubiquiotous iron oxide as a platform to accomodate SO 4 −, we functionalized iron oxide surface with SO 4 2- species, which could be transformed into surface SO 4 − species via radical transfer from aqueous OH species. Specifically, a series of SO 4 2--modified iron oxide catalysts were synthesized using SO 2 and O 2 at 300–600 °C in order to vary their surface properties such as the contents of surface Fe δ+ species acting as H 2 O 2 activators to form OH, the contents of surface SO 4 2- species functioning as surface SO 4 − precursor, and the character of S O bonds innate to SO 4 2- functionalities linked to their long-term stability. In addition to the comparison of energetics between SO 4 2- functionalities and their SO 4 - analogues via computation, a kinetic assessment of reaction runs were conducted under controlled environments to gather convincing evidence that the formation of surface SO 4 − via its radical interconversion with aqueous OH was highly plausible and that surface SO 4 − would be the major decomposer of phenol (model compound of recalcitrants). In addition, 500 °C was found to be the optimized temperature to greatly populate Fe δ+ and SO 4 2- species rigidly immobilized on iron oxide surface among all temperatures studied, thereby providing the greatest activity and recyclability to degrade phenol. [ABSTRACT FROM AUTHOR]

Disk-like α -Fe 2 O 3 hierarchical nanoparticles with diameters of 150–200 nm and a [1 1 0] preferred orientation have been prepared by a novel one-step method. The viscosity of the Shengli extra heavy oil reduced substantially through the combination of the α -Fe 2 O 3 nanoparticles and a hydrogen donor, which can be attributed to the changes in the oils' compositions after the catalytically pyrolytic reactions. • Disk-like α -Fe 2 O 3 nanoparticles with ca. 200 nm were prepared via a facile method. • The nanoparticles have a hematite structure with [1 1 0] preferred orientation. • The α -Fe 2 O 3 particles were used as the catalyst for the upgrading of heavy crude oil. • Combination of the nanoparticles and tetralin cause substantial viscosity reduction. • The changes in the oils' compositions account for the variations of the viscosities. In this paper, disk-like α -Fe 2 O 3 nanoparticles were synthesized by one-step via an n-octyl alcohol-mediated self-assembly process and were subsequently used as the catalyst for the updating of heavy crude oil. The characterization results show that the diameter of the as-prepared α -Fe 2 O 3 disks is in the range of 150–200 nm and the nanoparticles have a hematite structure with [1 1 0] preferred orientation. The catalyst strongly acts on the asphaltene and causes its lower S content and N content, lower aromaticity and aromatic condensation, and higher branchiness index. Adding tetralin causes the increment of aromatics content, the decrease of resin, and more molecules containing aromatic moieties bearing 2 and 3 rings. The viscosity of the Shengli extra heavy oil reduced substantially from 161180 mPa∙s to 45882 mPa∙s (50 °C) through the combination of the α -Fe 2 O 3 nanoparticles and tetralin (a hydrogen donor). [ABSTRACT FROM AUTHOR]

• Fe(OH) 3 and α-FeOOH show highest efficiency for H 2 S/O 2 removal among the 35 samples. • BET surface area and Bronsted acid sites drive adsorption of H 2 S and O 2. • Performance of α-FeOOH was substantiated in a pilot plant with raw biogas. This study deals with the development of iron oxide/hydroxide adsorbents for the alternating removal of H 2 S and O 2 from natural gas and biogas. The considered procedure initially implies the chemisorption of H 2 S. In the second step, O 2 is removed by reaction with the H 2 S-treated substrate accompanied by regeneration of the adsorbent. 35 different iron-based samples were physical-chemically characterized and tested towards H 2 S/O 2 break through behavior and adsorption capacity to evaluate structure-performance correlations. It was derived that high BET surface area, high proportion of meso and micro pores, small average pore diameter, low crystallinity and high number of Bronsted acid sites are crucial properties of the adsorbents. As a consequence, Fe(OH) 3 and α-FeOOH revealed highest efficiency for the successive adsorption of H 2 S and O 2 , while α-Fe 2 O 3 provided rather low performance. Mechanistic investigations were carried out with α -FeOOH and α -Fe 2 O 3 indicating rapid dissociation of H 2 S on α -FeOOH, while slow molecular adsorption prevailed on α -Fe 2 O 3. With proceeding H 2 S exposure, the adsorbents were partially transformed into sulfide and sulfate species with some formation of elemental sulfur. In subsequent reaction with O 2 , the H 2 S-exposed samples were re-oxidized under partial restructuring, whereas elemental sulfur and sulfate entities were additionally produced. Finally, the concept of the alternating adsorption of H 2 S and O 2 on best α -FeOOH substrate was technically evaluated in a biogas pilot plant. The investigations showed efficient conversion of H 2 S for 40–100 h, while subsequent O 2 conversion was achieved for ca. 5.5 h. [ABSTRACT FROM AUTHOR]

• Modification of the TiO 2 -hematite composites by ambient plasma. • Bandgap decreased from 3.2 to 2.8 eV by the ambient plasma. • Electron-transfer resistance decreased from 16 to 11 Ω by the ambient plasma. • Photocurrent response of the composites increased by 5.6 times compared to TiO 2. • The composite degraded methylene blue in 80 min compared to 180 min of TiO 2. Titanium dioxide (TiO 2)-hematite composites are synthesized by the hydrothermal method and modified further by using air plasma for photocatalytic applications. High photocurrent response of the composite, 5.6 times better than TiO 2 , is observed, and high efficient degradation of methyl blue (MB) within 80 min is shown when TiO 2 degraded MB in 180 min. It is found that the plasma treatment introduces electrochemical active surface area with formation of Ti3+ and oxygen vacancies and effectively reduces energy bandgap from 3.15 to 2.8 eV, electron-transfer resistance from 16 to 11 Ω, and particle size from 25 to 20 nm, compared to TiO 2. [ABSTRACT FROM AUTHOR]

• The solid-state chemistry in the oxygen carrier was investigated in real-time. • The Fe/MgAlFeOx oxygen carrier displays sequential reactions from Fe2O3 to Fe/Fe3C. • Fe-cations incorporate in the support at tetragonal position when FeII is formed. • Fe-cations release from the support when FeII is oxidized/reduced to FeIII/Fe0. In this work, a spray-dried Fe-based oxygen carrier with an in situ generated Mg 1-x Al 2-y Fe x+y O 4 -support was investigated during packed-bed chemical looping operation with methane at 900 °C. The evolution of the solid-state chemistry taking place in the oxygen carrier material was investigated in real-time with synchrotron X-ray diffraction while the spatial distribution of the phases was investigated using X-ray diffraction computed tomography (XRD-CT). These measurements revealed that some Fe-cations were systematically taken up and released from the spinel support. This take-up and release was shown to be strongly related with the oxidation state of the active phase. Although this take-up and release of Fe-cations decreased the amount of Fe-oxides active in the chemical looping process, the oxygen transfer capacity was still sufficiently high. The microstructure of the oxygen carriers along the length of the packed reactor bed was also investigated with scanning electron microscopy (SEM). The experiments indicate that the MgFeAlO x support with an extra Fe-based active phase is a promising material for oxygen carriers, as it forms a sustainable non-toxic, stable and green alternative to the typical Ni-based oxygen carriers, for hydrogen generation by chemical looping. [ABSTRACT FROM AUTHOR]

• AFMAlg composite hybrid beads were prepared for NO 3 − and PO 4 3− adsorption. • Hydro assisted AFMAlg composite beads demonstrate enhanced NO 3 − and PO 4 3− removal. • Complexation and electrostatic attraction support the NO 3 − and PO 4 3− adsorption. • The water quality parameters such as pH, TDS, Cl− and hardness were controlled at field conditions. The magnetic iron oxide (Fe 3 O 4)/alginate (Alg) (MAlg) composite beads were synthesized and utilized for the nitrate (NO 3 −) and phosphate (PO 4 3−) retention. To enhance the functional behaviour and sorption capacity of MAlg composite beads, the amine groups were grafted to get the amine functionalized MAlg (AFMAlg) composite beads via, in situ precipitation (In situ) and hydrothermal (Hydro) techniques. The hydro assisted AFMAlg composite beads hold the unique advantages like high porous nature and large surface area than the other adsorbents prepared by in situ method for NO 3 − and PO 4 3- removal. Several characterization studies such as XRD, FTIR, SEM, VSM, BET and EDAX analysis were explored. The parameters responsible for sorption process like contact time, solution pH, co-anions, adsorbent dosage, initial adsorbate concentration and temperature were optimized in batch scale. The nature of NO 3 − and PO 4 3− sorption was verified by fitting the experimental data with various isotherms, kinetics and thermodynamic parameters. The field applicability and regeneration studies of the AFMAlg composite beads were also performed. [ABSTRACT FROM AUTHOR]

Different α-Fe 2 O 3 porous architectures were obtained by electrospinning (nanotubes) or without electrospinning (flakes), and heating treatments using Fe(NO 3) 2 /PVP (Polyvinylpyrrolidone) as a precursor. The particles constituting the nanotubes and flakes samples exhibited similar wall porosity and crystal size, while the existence of the micropore area was also a characteristic. The chemical identity was confirmed as hematite by XRD, Raman and XPS studies. The prepared samples were studied as photocatalytic materials in the removal of NO X gases from air, their De-NO X ability being superior to that previously reported for hematite photocatalysts. These porous hematite samples exhibited a high NO conversion efficiency and similar to that of TiO 2 P25, this being the first report for α-Fe 2 O 3 oxide. Additionally, the calculated De-NO X selectivity values were higher than that of TiO 2 P25. The adsorption of NO 2 molecules is facilitated on these porous architectures, assisting in the enhancement of the of the photochemical process selectivity. Image 1 • Porous architectures act as new enhanced Fe 2 O 3 photocatalysts in De-NO X processes. • A high NO conversion efficiency similar to that of TiO 2 P25 is obtained. • The adsorption of NO 2 molecules is facilitated by the large micropore area. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles based on Fe 3 O 4 and their modifications of surface with therapeutic substances are of great interest, especially drug delivery for cancer therapy includes boron-neutron capture therapy. The results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane iron oxide nanoparticles are presented. Energy-dispersive X-ray analysis and Fourier transform infrared spectroscopy with attenuated total reflection (ATR) accessory confirmed change of nanoparticles elemental content after modification and formation of new bond between Fe 3 O 4 and attached molecules. Scanning and transmission electron microscopy showed that Fe 3 O 4 nanoparticles average size is 18.9 nm. Phase parameters were investigated by powder X-ray diffraction, Fe 3 O 4 nanoparticles magnetic behavior was evaluated by Mössbauer spectroscopy. Chemical and colloidal stability was studied using simulated body fluid (phosphate buffer – PBS). Modified nanoparticles have excellent stability in PBS (pH = 7.4), characterized by X-ray diffraction, Mössbauer spectroscopy and dynamic light scattering. Fe 3 O 4 biocompatibility was elucidated in-vitro using cultured mouse embryonic fibroblasts. The obtained results show the increasing of IC 50 from 0.110 mg/ml for Fe 3 O 4 to 0.405 mg/ml for Fe 3 O 4 -Carborane nanoparticles. Obtained data confirm biocompatibility and stability of synthesized nanoparticles and potential to use them in boron-neutron capture therapy. • Fe 3 O 4 nanoparticles (NPs) with 18.9 nm average size were synthesized and modified with APTMS. • NPs were characterized using FTIR, SEM, TEM, XRD, DLS, Mössbauer spectroscopy and VSM methods. • Modified NPs have excellent stability in simulated body fluid. • Carborane borate with 21 boron atoms was immobilized on NPs through the ionic interaction. • Synthesized modifed NPs are excellent candidates for using in boron-neutron capture therapy. [ABSTRACT FROM AUTHOR]

• Iron oxide doped carbon nitride was synthesized. • Doped photocatalyst was proven better than pure carbon nitride. • Photon concentrator was fabricated by 3D printing. • Dicamba was degraded by photocatalyst/H2O2 exposure under visible light. We have synthesized iron oxide doped carbon nitride with 0.5 to 2 wt.% iron oxide and characterized by XPS, TGA, FTIR, SEM, photoluminescence spectroscopy and photoelectrochemical measurements. A herbicide, dicamba was employed as model organic pollutant for degradation in presence with the catalyst and hydrogen peroxide. A 3D printed photon concentrator with two chips on board (COB) LEDs with visible light spectra and two complex parabolic mirror surfaces was used as photo-reactor. The findings revealed that both photocurrent and degradation of dicamba were functions of light intensity and concentrator geometry. The rapid degradation of dicamba can be attributed to the holistic and individual actions of structural components of the photocatalyst. Four distinct phenomena, including photocatalytic activity of carbon nitride, quenching of electron/hole pairs and generation of additional reactive hydroxyl radicals by hydrogen peroxide, Fenton and photo-Fenton activity of iron oxide component of carbon nitride in presence of hydrogen peroxide and photocatalytic activity of iron oxide alone in conjuncture with carbon nitride can contribute to the overall photocatalytic activity of the system. Liquid Chromatography-Mass spectrometry (LCMS) analysis of the degradation products showed loss of chlorine from the aromatic ring and evidence of free radical addition reactions in the course of photocatalysis. [ABSTRACT FROM AUTHOR]

To develop an efficient and reusable heterogeneous Fenton-like catalyst is a great challenge for its application in practical water treatment. Effective oxygen vacancy (OVs)-promoted Fe 2 O 3 -CeO 2 catalyst was prepared by a sol-gel method, and applied in the heterogeneous Fenton-like reaction of the sulfamerazine (SMR) degradation. The Fe 2 O 3 -CeO 2 catalyst showed good activity and stability, and total SMR conversion was achieved in the Fenton-like reaction after 75 min at pH 3.0 and 45 °C under O 2 atmosphere. Moreover, the SMR removal was significantly enhanced under O 2 atmosphere. The surface-bounded OH radicals played a dominant role for the SMR degradation. The Fe 2 O 3 -CeO 2 catalyst remarkably promoted the generation of OH in the Fenton-like reaction under O 2 atmosphere, mostly because abundant OVs on the catalyst surface not only accelerated electron transfer to promote the H 2 O 2 decomposition, but also oxygen molecules, adsorbed on OVs, formed O 2 −/HO 2 and promoted the Fe2+/Fe3+ redox cycle. Image 1 • The Fe 2 O 3 -CeO 2 catalyst exhibited good activity and stability in the Fenton-like SMR degradation. • The activity of the Fe 2 O 3 -CeO 2 catalyst was enhanced under O 2 atmosphere. • OVs on the Fe 2 O 3 -CeO 2 catalyst improved the generation of OH radicals. • Surface-bounded OH played a critical role in the Fenton-like system. • The reaction mechanism over the OVs-promoted Fe 2 O 3 -CeO 2 catalyst was proposed. [ABSTRACT FROM AUTHOR]

In this study, Fe 3 O 4 /MnO 2 /FA nanocomposite was synthesized as a low cost adsorbent with high adsorption capacity, desorption efficiency and reusability for Sr(II) extraction from seawater. FT-IR, FESEM-EDS, XRD, VSM and BET experiments were used to characterize the composite. Sr(II) adsorption onto Fe 3 O 4 /MnO 2 /FA followed a pseudo-first-order kinetic model and was well fitted with the Langmuir isotherm model. Fe 3 O 4 /MnO 2 /FA has demonstrated an excellent adsorption capacity of 227.3 mg/g for Sr(II) ions at 25 °C and pH 8. The composite showed high selective uptake of Sr(II) in the presence of cations Na, Mg and Ca. However, Ca ions reduced the Sr(II) uptake from 49.1 to 41.0 mg/g at 600 mg/L Ca. Sr(II) desorption was performed using 0.1 M HCl which showed an excellent desorption efficiency. In natural seawater containing 9.4 mg/L Sr(II), without changing the physicochemical conditions, Fe 3 O 4 /MnO 2 /FA composite showed 6.4 mg/g of Sr(II) adsorption, which leads to save time and energy consumption. Unlabelled Image • Fe 3 O 4 /MnO 2 /FA composite was prepared to extract Sr(II) from seawater. • Fe 3 O 4 /MnO 2 /FA showed high selective uptake of Sr(II) in the presence of coexisting ions in seawater. • Fe 3 O 4 /MnO 2 /FA demonstrated an excellent Sr(II) adsorption capacity 227 mg/g. • Sr(II) desorption was easily performed by acid treatment and reused for repeated cycles. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • CLDH was derived by adding dry reforming into chemical looping hydrogen generation. • Syngas with an adjustable H 2 /CO ratio was produced through the CLDH process. • The reduced iron oxide shows a high selectivity on syngas generation. • Partial oxidation occurred with dry reforming promoted the H 2 /CO ratio and H 2 yield. Abstract A chemical looping dry reforming process for co-production of hydrogen and syngas was proposed. This process contains four different stages, i.e. reduction, dry reforming, steam oxidation and air oxidation. The partial oxidation of CH 4 with lattice oxygen occurred along with dry reforming reaction on the reduced iron oxide in the dry reforming stage, which helps to obtain the flexibility syngas ratio and increase hydrogen yield in the next steam oxidation stages. In this study, Fe 2 O 3 /Al 2 O 3 oxygen carrier was used to verify the feasibility of this process in a fluidized-bed reactor at 900 °C and 1.01 bar. Carbon deposition and physical properties of the carrier were studied by using O 2 -TPO, XRD and BET methods. It was found that the efficient conversion of CO 2 and CH 4 to syngas can be achieved on the reduced iron oxygen carrier. When the feed ratio of CH 4 /CO 2 was 1 and the reduction extent of iron was 33%, the CH 4 conversion and syngas yield (the output of syngas/the input of CH 4) reached 98.32% and 3.84 during the dry reforming stage, respectively. Moreover, increasing the feed ratio of CH 4 /CO 2 raised the H 2 /CO ratio of syngas, but the deposited carbon would form with the available lattice oxygen depleted. Finally, superior redox activity and stability were obtained during the 15 cycles, although slight sintering was observed on the reacted oxygen carrier. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Highly active and selective composite photocatalysts were developed for NO x abatement under visible-light illumination. • Structure of mesoporous graphitic (mpg) C 3 N 4 was synthetically fine-tuned for optimum photocatalytic performance. • Photocatalytic NO x abatement activity, selectivity and reusability of C 3 N 4 was further improved by Fe 3 O 4 -NP incorporation. • Fe2+/Fe3+ species increased oxygen reduction capacity of C 3 N 4 resulting in lower NO 2 production and higher selectivity. • Fe 3 O 4 /C 3 N 4 photocatalyst had a positive DeNOx index, making it a viable DeNOx photocatalyst under VIS light at RT. Abstract Several mesoporous graphitic carbon nitride (mpg -C 3 N 4) photocatalysts were synthesized by using a hard-templating method comprising thermal polycondensation of guanidine hydrochloride over silica spheres at three different temperatures (450, 500 and 550 ℃). After structural characterization of these mpg -C 3 N 4 photocatalysts, they were tested in NO(g) photo-oxidation under visible (VIS) light. The effects of polycondensation temperature on the structure and photocatalytic performance of mpg -C 3 N 4 in NO photo-oxidation were studied. The results revealed that polycondensation temperature has a dramatic effect on the photocatalytic activity of mpg -C 3 N 4 in NO photo-oxidation, where mpg -C 3 N 4 synthesized at 500 ℃ (mpg -CN500) showed the best performance in NO x abatement as well as a high selectivity towards solid state NO x storage under VIS light illumination. Photocatalytic performance of the mpg -CN500 was further enhanced by the anchoring of 8.0 ± 0.5 wt.% Fe 3 O 4 nanoparticles (NPs) on it. Fe 3 O 4 / mpg -CN500 photocatalyst showed both high activity and high selectivity along with extended reusability without a need for a regeneration step. Enhanced photocatalytic NO x oxidation and storage efficiency of Fe 3 O 4 / mpg -CN500 photocatalyst was attributed to their mesoporous structure, high surface area and slow electron-hole recombination kinetics, efficient electron-hole separation and facile electron transfer from mpg -CN500 to Fe 3 O 4 domains enhancing photocatalytic O 2 reduction, while simultaneously suppressing nitrate photo-reduction and decomposition to NO 2 (g). [ABSTRACT FROM AUTHOR]

Fe 2 O 3 nanoparticles (NPs) coated by the SiO 2 shell with a thickness up to ˜6.5 nm were synthesized by a fast and facile microwave irradiation approach. The thickness of the SiO 2 shell around Fe 2 O 3 NPs could be controlled by varying tetraethoxysilane (TEOS) concentration as well as avoiding individual SiO 2 particle formation. The synthesized Fe 2 O 3 @SiO 2 core-shell nanocomposites (NCs) were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The bigger particle size compared to the uncoated Fe 2 O 3 NPs and Si O Si asymmetric stretching vibrational band at 1101 cm−1 in the prepared NCs obtained by FE-SEM and FT-IR study, respectively anticipated the successful SiO 2 coating on Fe 2 O 3 NPs. The presence of homogeneous silica layer was authenticated by TEM observation. The change in binding energy of Fe 2p3 and Si 2p in the synthesized NCs compared to the uncoated Fe 2 O 3 and pure SiO 2 NPs corroborated the formation of Fe O Si bond at the interface of Fe 2 O 3 (core) and SiO 2 (shell). The existence of magnetic property in the prepared NCs, even above the Curie temperature of Fe 2 O 3 , was assured by vibrating sample magnetometer (VSM) study. This observation will undoubtedly inspire to design and fabricate novel heterostructures of iron oxide to retain its magnetization at high temperature. [ABSTRACT FROM AUTHOR]

In this work, we present the magnetic and structural properties of α-Fe 2 O 3 nanoparticles synthesized by the hydrothermal synthesis method. XRD, FTIR and Raman spectroscopy indicate that the samples consist of single-phase α-Fe 2 O 3 nanoparticles. A microstructural analysis by TEM and SEM shows: (i) irregular nanoparticles (∼50 nm), (ii) plate-like nanoparticles (with thickness t∼10 nm and diameter d∼50–80 nm) and (iii) microsized ellipsoid 3D superstructures (with length l∼3.5 and diameter d∼1.5 μm) composed of nanosized building blocks (∼50 nm). We used circularity, elongation and convexity measures to quantitatively analyze the shape of the particles. Irregular hematite nanoparticles were synthesized using a water solution of ferric precursor and sodium acetate during the hydrothermal reaction (reaction conditions: T = 180 °C, t = 12 h). The same hydrothermal reaction temperature, reaction duration and ferric precursor (without sodium acetate) were used for synthesizing hematite ellipsoid 3D superstructures. Addition of urea and glycine surfactants in hydrothermal reaction resulted in the formation of nanoplate hematite particles. The role of these surfactants on the structure and morphology of the particles was also investigated. Magnetic measurements at the room temperature displayed a wide range of coercivities, from H C = 73 Oe for irregular nanoparticles, H C = 689 Oe for nanoplates to H C = 2688 Oe for hematite ellipsoid 3D superstructures. The measured coercivity for the ellipsoid superstructure was about 35 times higher than in the case of irregular hematite nanoparticles and about 4 times than the coercivity of hematite nanoplates. Magnetic properties of synthesized samples were related to their structure and morphology. We conclude that shape anisotropy influenced enhancement of the coercivity in hematite nanoplates whereas hematite ellipsoid 3D superstructure (nanoparticle clusters) induced the formation of multidomain magnetic structure and highest coercivity revealing its superior structure for enhanced magnetic properties. The synthesized hematite nanoparticle structures exhibit low cytotoxicity levels on the human lung fibroblasts (MRC5) cell line demonstrating a safe use of these nanoparticles for practical applications. Image 1 • Uniform hematite nanostructures are synthesized by hydrothermal method. • H C depends on the particle structure and shape. • High coercivity is observed in hematite nanoparticle superstructure. • Low cytotoxicity and good cell internalization are observed. [ABSTRACT FROM AUTHOR]

Hormuz Island is a salt diapir in southern Iran, which also comprises transported blocks of rhyolitic and rhyodacitic rocks, which were brought to the surface during the island's diapiric emergence from the Persian Gulf. The rhyolites (558 ± 7 Ma) and rhyodacites, have both formed from the same peraluminous calc-alkaline I-type magma, in a volcanic arc settings at an active continental margin. The volcanic rocks contain significant quantities of accessory apatite. The majority of the small crystals of apatites (type-I) have crystallized during an early magmatic phase. Additionally, large single crystals of apatite (type-II) occur together with magnetite in veins within the rhyodacite rocks. The geochemical investigation of the two types of apatite revealed they both formed from the same magma source. Based on the microthermometric characteristics of primary fluid inclusions, two different events during the formation of apatite type-II crystals were distinguished. Our study revealed that in addition to the igneous fluids, a second set of fluid inclusions was trapped in the core of the crystals, indicating a post magmatic interaction with external basinal fluids during the growth of apatite type-II. On Hormuz Island, iron oxides occur as well in different styles from massive iron oxide bodies, magnetite-apatite veins, to red magnetic-hematitic soils. Based on the volcanic structures and textures of the massive iron oxide bodies as well as geochemical results from the magnetite, it is proposed that a source potential for both Fe and P could have been an immiscible iron-rich volatile phase which evolved from the parental felsic magma. Results from fieldwork, microscopy, and geochemistry revealed that mega-crystals of hematite and specularite in the magnetite-apatite veins were formed from magmatic-hydrothermal fluids released from the crystallizing magmas. The occurrence of exotic banded iron ores, red soils and alternating bands of hematite with evaporite minerals could be the result of seawater-rhyolite interactions by circulating exhalative hydrothermal fluids. • The Hormuz Island (Iran) apatites and iron oxides are described. • Apatite and iron oxides recorded the petrogenetic information of the parental magma. • The two types of apatite are formed from the same calc-alkaline and I-type magma source. • We provided a magmatic model involving immiscibility in silicate and iron oxide-rich melts. • Seawater-rhyolite interactions by circulating hydrothermal fluids made different iron oxide's styles. [ABSTRACT FROM AUTHOR]

A magnetic adsorbent namely magnetic iron oxide encrusted hydrocalumite-chitosan (Fe 3 O 4 @HCCS) composite was prepared by the fabrication of magnetic iron oxide (Fe 3 O 4) particles on hydrocalumite-chitosan (HCCS) composite for fluoride sorption studies in batch mode. The prepared magnetic Fe 3 O 4 @HCCS composite possesses an enhanced defluoridation capacity (DC) of 6.8 mg/g compared to hydrocalumite (HC) which possesses the DC of 2.4 mg/g. The various physico-chemical parameters such as contact time, pH, co-existing anions, initial fluoride concentration and temperature were optimized for the maximum fluoride removal. The structural changes of the sorbent, before and after fluoride sorption were studied using FTIR and SEM with EDAX techniques. The equilibrium data was well modeled by Freundlich and Langmuir isotherms. The thermodynamic parameters revealed the feasibility, spontaneity and endothermic nature of fluoride sorption. The field performance and efficiency of Fe 3 O 4 @HCCS composite was examined with the waste-water sample collected from a fluoride endemic area of Dindigul district, Tamilnadu, India using standard protocols. [ABSTRACT FROM AUTHOR]

Abstract Photocatalytic water purification has emerged as new effective ways for an environment preserve and purification in few decades. As a part of studies on photocatalytic water purification, constructing heterojunction structured compounds with different photocatalysts for efficient organic pollutant degradation is regarded as key-strategy. Herein, facile one-step carbonizing process was introduced for synthesizing Fe 2 O 3 /C-g-C 3 N 4 based Z-scheme heterojunction photocatalyst. The two times of photocatalytic organic pollutant degradation rate of Fe 2 O 3 /C-g-C 3 N 4 based Z-scheme heterojunction photocatalyst was enhanced comparing with pristine Fe 2 O 3 /g-C 3 N 4 heterojunction photocatalyst through rhodamine B (RhB) degradation under AM 1.5G (100 mWcm−2, 1 sun) illumination. The reasons for enhanced photocatalytic RhB degradation efficiency of Fe 2 O 3 /C-g-C 3 N 4 based Z-scheme heterojunction photocatalyst were revealed to efficient charge transfer during light induced RhB degradation reaction by constructing junction structures among Fe 2 O 3 , amorphous carbon layer and g-C 3 N 4 , which proved by fluorescence spectroscopy, XPS, SEM, TEM and UV–Vis analysis. Graphical abstract Image 1 Highlights • Fe 2 O 3 /g-C- 3 N 4 (Fg) and Fe 2 O 3 /C-g-C 3 N 4 (FCg) heterojunction photocatalysts synthesized via simple solid-state reaction. • Z-scheme heterojunction between Fe 2 O 3 and g-C 3 N 4 was constructed by insertion of amorphous carbon layer. • Photocatalytic activities of double charge transfer or Z-scheme heterojunction between Fe 2 O 3 and g-C 3 N 4 was studied. [ABSTRACT FROM AUTHOR]

The correlation between the content and morphology of Fe 2 O 3 and the yields of polychlorinated dibenzo- p -dioxins and polychlorinated dibenzofurans (PCDD/Fs) was studied in this work. Three fly ash surrogates containing 1%, 2.5%, and 4% of Fe 2 O 3 were prepared and their effects on PCDD/Fs formation were investigated and compared to our previously studied 5% iron oxide sample using 2-monochlorophenol precursor model. As the intermediate of PCDD/Fs, environmentally persistent free radical formation propensity was correlated with the PCDD/Fs formation yields for different iron oxide samples. PCDD/Fs yield increases exponentially with the increasing iron content under pyrolytic conditions. On the contrary, low iron oxide content promotes oxidation and lowers yields of PCDD/Fs. Changing iron oxide clusters' morphology (crystallinity and cluster size) affects the mechanism of PCDD/Fs formation – on larger crystallites, a bidentate chemisorption of precursor is preferred leading to lower chlorinated congeners, while smaller clusters promote formation of PCDFs through mixed monodentate-bidentate surface species, resulting in formation of congeners with 1 chlorine more. This study further confirms the propensity of iron oxide to predominantly form PCDFs. The iron content also defines PCDDs:PCDFs ratio. • The crystallinity and cluster size increases with increasing Fe 2 O 3 content in fly ash, which enhances total PCDD/Fs yield. • The PCDD/F yield is positively correlated with the concentration of EPFRs, which are intermediates in the formation of PCDD/Fs. • The content of iron oxide in fly ash determines PCDFs congener pattern and the ratio of PCDDs to PCDFs. [ABSTRACT FROM AUTHOR]

In this research, Fe 3 O 4 particles were magnetically manipulated to create porous scaffolds using a tri-axial nested Helmholtz coils-based freeze-casting setup. This novel setup allowed for a uniform magnetic field to be applied in any direction and for it to effectively change directions at any time. Applying a uniform low magnetic field of 7.8 mT in various directions was investigated to fabricate a variety of tailored microstructures and mechanical properties in the resultant scaffolds. It was observed that using the magnetic field aligned up to 81% of the lamellar walls and also altered the area and shape of the pores of the resultant scaffolds. This lamellar wall alignment occurred at every applied magnetic field direction due to the Fe 3 O 4 particles aligning during the freeze-casting process. As a result of this alignment, increases in the mechanical properties of up to 4.1× were observed. The results provide a novel experimental technique for the fabrication of user-defined microstructures in Fe 3 O 4 -based freeze-cast materials that provides significant advantages over previous experimental setups for magnetic freeze casting. Image 1 [ABSTRACT FROM AUTHOR]

Microbial fuel cell (MFC) technology has been widely experimented nowadays, as it is a promising clean energy technology, which can harvest bioelectricity while simultaneously treating wastewater. Platinum (Pt), a precious transition metal, has long been regarded as a superior catalyst material for oxygen reduction reaction (ORR) at the cathode of the MFCs, however the high cost associated with it clutch it back for field scale applications. In this study, Co 3 O 4 or Fe 3 O 4 was blended with synthetically prepared conductive ink to act as microporous layer to explore its efficacy as an ORR catalyst. Applicability of these catalysts on cathode was investigated in dual chambered aqueous cathode MFCs and the performance was compared with MFC without any cathode catalyst, MFC with only conductive ink and another MFC with Pt as benchmark ORR catalyst. X-Ray diffraction, Fourier transform infrared spectra, Raman and field emission scanning electron microscope analysis were done to characterize the prepared catalysts. Cathode containing Co 3 O 4 with conductive ink demonstrated higher reduction current (- 30 mA) than cathode having Pt and conductive ink with Fe 3 O 4 (- 9 mA each) during cyclic voltammetry analysis. MFCs having cathodes printed with conductive ink containing Co 3 O 4 and Fe 3 O 4 exhibited a maximum volumetric power density of 6.62 W m−3 and 5.06 W m−3, respectively, which were much higher than the one without any catalyst (2.95 W m−3). Similarly, coulombic efficiency (CE) of 22.3%, 17.1% and 11.2% was observed in MFCs having cathode with conductive ink containing Co 3 O 4 or Fe 3 O 4 and without any catalysts, respectively. Moreover, more than 90% chemical oxygen demand removal efficiency was observed for MFCs having cathode with conductive ink containing Co 3 O 4 or Fe 3 O 4. Importantly, the performance obtained from MFC with conductive ink blended Co 3 O 4 was found superior compared to MFC having Pt as cathode catalyst, where later produced power density of 6.13 W m−3 and CE of 21.1%. Hence, it can be concluded that Co 3 O 4 can be used as an alternative to expensive platinum for efficient ORR in MFCs to make this technology effective for field scale application. • Conductive ink printed Co 3 O 4 or Fe 3 O 4 cathode catalyst improve MFC performance. • MFC with conductive ink printed Co 3 O 4 cathode gave higher power density than Pt. • 22% Coulombs recovery observed with conductive ink printed Co 3 O 4 as cathode catalyst. • Electrochemical analysis showed higher redox activity of the fabricated materials. [ABSTRACT FROM AUTHOR]

The effect of alloying of sputter-deposited Fe with 9 at.% tungsten on the growth of nanoporous anodic oxide was studied in ethylene glycol electrolyte containing 0.1 mol dm−3 ammonium fluoride and 1.5 mol dm−3 water. The classic nanoporous anodic film (Al 2 O 3 -like) was developed on pure Fe while the transition of nanopores to nanotubes (TiO 2 -like) was observed for anodizing of Fe-W alloy. The pores/nanotubes having average diameter 50–110 nm and 30–60 nm on pure Fe and Fe-W alloy anodized at voltage 40–60 V, respectively. Both nanoporous/nanotubular anodic films grow in line with the field assisted flow model with a few fundamental details: i) transition of nanopores to nanotubes is observed upon anodizing of Fe-W alloy, ii) significant reduction of the cell size (nanotube diameter) is obtained on Fe-W alloy, iii) relatively thick layer is produced at Fe-W alloy/oxide interface. The primary reason of this transition to nanotubes as well as chemical changes is discussed in view of effective modification of the cell boundary region with tungsten species, probably WF 6 compound, upon growth of anodic film under influence of high electric field strength. The possible reason of developing the space in between nanotubes is faster kinetics of WF 6 reaction with water over the presence of low solubility FeF x species. Alloying of iron is one of the effective ways to modify the nanostructure of the anodic film on iron. Image 1 • Anodizing of Fe with addition of 9 at.% of W results in transition of nanoporous oxide into nanotubular structure. • Anodic nanotubes formed on Fe-W alloy composed of Fe x O y and WO 3 domains grow in line with the field assisted flow model. • Faster kinetics of WF 6 decomposition over the presence of low solubility FeF x is observed. [ABSTRACT FROM AUTHOR]

Iron oxide (Fe 2 O 3) thin films have been prepared starting from iron chloride (FeCl 3) precursor by spray pyrolytic decomposition of FeCl 3 on an ordinary glass substrate at 450 °C. The precursor concentration (C) has been varied from 0.06 to 0.3 mol l−1 keeping the other deposition parameters fixed. The (C) effect on the structural, optical and electrical properties has been studied. The XRD analysis shows that Fe 2 O 3 thin film has a rhomboedric structure with (104) plane as preferential orientation. A degradation of crystallinity followed by a change in plan orientation from (104) to (110) has been observed, when (C) has been raised to 0.2 mol.l−1.The optical transmittance spectrum shows that T(λ) decreases at higher precursor concentration. Optical band gaps w decreased from 2.21 to 2.08 eV for direct transition and from 2.03 to 1.99 eV for indirect transition when (C) increases from 0.06 to 0.3 mol l−1. The extinction coefficient (k) and refractive index (n) were also has been estimated and studied. The films deposited with C = 0.14 mol l−1 has shown the maximum mobility of 62 cm2 V−1.s−1 at room temperature. All physical properties of Fe 2 O 3 thin films investigated in this work were strongly dependent upon the precursor concentration. The obtained results provide valuable information about structural, optical, photoluminescence and electrical properties of sprayed Fe 2 O 3 , which is a very helpful issue for better understanding and perfection of the semiconductor quality for the optoelectronic application. • Iron oxide thin films were grown successfully on glass substrate by chemical spray pyrolysis technique. • Precursor concentration effects were investigated. • Structural, optical and electrical properties were studied. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fe 3 O 4 nanorods were produced from Fe(II) and Fe(III) ions using Salvia hispanica essential oil. • Advanced statistical methods were applied to find the optimal conditions for size-defined synthesis of Fe 3 O 4 nanorods. • The Fe 3 O 4 nanorods were characterized using TEM, EDX, SAED, XRD, SQUID, and ATR FT-IR. • Fe 3 O 4 nanorods displayed electromagnetic excitation, a feature useful for microwave-imaging of tissues. Abstract Salvia hispanica (chia) essential oil was applied for successful production of magnetic nanorods. The influence of several parameters, i.e. temperature of the reaction mixture, volume of the S. hispanica essential oil solution, stirring speed of the reaction mixture, and flow rate of the N 2 protective gas, on their axial length was studied. A design of experiments (DOE) approach followed by the response surface methodology (RSM) identified the optimal conditions for synthesis of ∼3 nm magnetic nanorods. The granulometric and magnetic properties of these magnetite nanorods were analyzed using transmission electron microscopy (TEM), energy dispersive X-ray scattering (EDX), selected area electron diffraction spectroscopy (SAED), X-ray diffraction (XRD), and superconducting quantum interference device (SQUID) magnetometer. These methods revealed that the produced magnetic nanorods had a crystalline cubic inverse spinel structure with an average axial length of 43.4 ± 20.5 nm, diameter of 3.6 ± 0.9 nm, and aspect ratio of 12.1 ± 5.2 nm, and they suggested the presence of spin glass-like (mictomagnetic) behavior with both ferro- and antiferromagnetic interactions. In addition, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR) was used to identify functional groups of the organic compounds present in S. hispanica essential oil that were possibly responsible for production and surface functionalization of the magnetite nanorods. The resultant magnetic nanofluid displayed electromagnetic excitation when exposed to microwave radiation, and therefore it could be useful in microwave-imaging of tissues. [ABSTRACT FROM AUTHOR]

Abstract Naphthols are industrial contaminants occurring widely in soils and waters. Remediation of organic pollutants can be done by chemical oxidation using persulfate. However, most research experiments testing degradation of organic pollutants have been done in ideal conditions, e.g. using a pure compound in pure water, and thus are weakly representative of real natural conditions where pollutants occur in complex mixtures of numerous organic compounds. Therefore we tested here the effect of the presence of small organic acids, as typical compounds occurring in natural media, on the degradation of 1-napthol with persulfate and iron oxides. Results show that organic acids decreased naphthol transformation by 3.7% for malic acid, 53.2% for tartaric acid, 72.3% for citric acid and 77% for oxalic acids, in a magnetite/persulfate system during 10 h. Meanwhile, the dissolved Fe species increased gradually with the reaction time; the highest concentration of Fe ions reached to ∼18 μM L−1 in aqueous phase. Electron paramagnetic resonance technique was applied to determine reactive oxygen species (ROS). The spin density of ·OH, detected as the main ROS, decreased initially, followed by gradually increase, suggesting that organic acids might inhibit the degradation of 1-naphthol by competing with ·OH. These findings disclose the high inhibition of the transformation by organic acids, and thus, more generally, imply that studies using only pure contaminants are weakly representative for remediation of real, natural samples. Graphical abstract Image 1 Highlights • LMWOAs exhibit inhibitory effect on 1-naphthol degradation in iron oxide/PS systems • Both of LMWOA molecular structure and iron oxide type affect 1-naphthol degradation • LMWOAs inhibit the heterogeneous activation via competition sorption on Fe surface • LMWOAs can dissolve iron oxides ions and improve the homogeneous activation of PS [ABSTRACT FROM AUTHOR]

Design of a multifunctional magnetic bionanosystem has become increasingly important towards advancing the future of clinical medicine. While hollow iron oxide nanoparticles with enhanced surface areas allow for more drug molecules to be attached to the particles, their relatively low saturation magnetization (M S) hinders their practicality in medicinal applications such as drug delivery and hyperthermia therapy. We demonstrate that this limitation can be overcome by utilizing 1D magnetic nanotubes that possess both enhanced surface areas and high M S. In this study, highly crystalline, tunable aspect ratio Fe 3 O 4 nanotubes have been successfully synthesized using a hydrothermal method. Magnetic measurements showed a clear Verwey transition (∼120 K) and high M S (∼75 emu/g) at 300 K, confirming the high quality of the synthesized Fe 3 O 4 nanotubes. Calorimetric experiments on randomly dispersed Fe 3 O 4 nanotubes in water with concentration of 1 mg/mL showed a large Specific Absorption Rate (SAR) value of 400 W/g for an AC magnetic field of 800 Oe, which increased to 500 W/g when the nanotubes were aligned parallel to the DC magnetic field and suspended in a 2% agar solution. Our study shows the possibility of using the Fe 3 O 4 nanotubes as a highly effective multifunctional nanoscale tool for targeted hyperthermia and on-demand drug delivery. • Hydrothermal synthesis of highly crystalline, tunable aspect ratio Fe 3 O 4 nanotubes. • Systematic study of the growth mechanism of the nanotubes. • The presence of Verwey transition and high M S (75 emu/g) at 300 K. • Nanotubes exhibited large SAR value compared to their hollow counterparts. • Dual-purpose applications in hyperthermia and on-demand drug delivery. [ABSTRACT FROM AUTHOR]

Abstract This article describes the synthesis, characterization and in vivo cytotoxic evaluation of thiol-functionalized superparamagnetic iron oxide magnetic nanoparticles (SPIONs). They have been employed as potential vehicles for a large number of biomedical applications, such as drug delivery. Fe 3 O 4 nanoparticles were synthesized by coprecipitation of iron salts and coated with L-cysteine. The physicochemical, morphological, and magnetic properties of Cys-Fe 3 O 4 nanoparticles were characterized by different experimental techniques. To evaluate their applicability in nanomedicine we evaluated their cytotoxicity using Balb/C mice. The results show that Cys-SPIONs are good candidates as nanocarriers in biomedical applications. Graphical abstract Unlabelled Image Highlights • Cys-Fe3O4 shows superparamagnetic behavior at room temperature. • Cys-Fe3O4 NPs show good colloidal stability. • Successful application of Cys-Fe3O4 as a biocompatible carrier in in vivo assays • The NPs do not interfere in ferric homeostasis. [ABSTRACT FROM AUTHOR]

Iron oxide has been widely studied in chemical looping hydrogen generation (CLHG) process as an oxygen carrier, but fast decline of its activity in redox cycles due to sintering and agglomeration is one of the main drawbacks. In this work, the colloidal crystal templated (CCT) method was applied to synthesize Fe 2 O 3 /CeO 2 oxygen carrier and the mole ratio of Fe/Ce was 8:2, aiming to inhibit adjacent grains from agglomerating and improve the contact between the fuel gas and the oxygen carrier. The redox performances were evaluated with CO as fuel in a batch fixed bed reactor for 20 redox cycles, with oxygen carriers prepared by co-precipitation (CP) and sol-gel (SG) methods as references. X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and H 2 -temperature programmed reduction (H 2 -TPR) were used for characterization. The results showed that the calcination temperature lower than 750 °C was suitable for the CCT. The redox experiments showed that the H 2 yield and the redox stability for the oxygen carrier prepared by CCT were higher than those by co-precipitation and sol-gel methods. The H 2 yield of CCT oxygen carrier kept stable from the 3rd cycle and was 8.5 mmol/gOC in the 20th cycle. The pore structures resulting from CCT were different from another two oxygen carriers before and after the cycles, but maintained well through SEM images, leading to high activity and stability during redox cycles. The crystallite sizes of Fe 2 O 3 and CeO 2 before and after redox cycles were the smallest for the CCT oxygen carrier from XRD patterns. In addition, H 2 -TPR demonstrated that CCT oxygen carrier exhibited the highest reactivity. • Colloidal crystal templated (CCT) is desirable for Fe 2 O 3 /CeO 2 preparation in CLHG. • The calcination temperature lower than 750 °C was suitable for the CCT. • The superior performance of CCT oxygen carrier can be ascribed to its pore structure. • The H 2 yield of the CCT oxygen carrier was 8.5 mmol/gOC after 20 cycles. [ABSTRACT FROM AUTHOR]

Highlights • Cobalt-doped α-Fe 2 O 3 particles exhibits unique hard magnetism. • Without calcination, its coercivity is found to increase as raising temperature. • After calcination, its coercivity falls into decline as temperature rise. • Defects in α-Fe 2 O 3 , Co colonies, FeOOH and CoFe 2 O 4 impurities are responsible. Abstract In this work, hard magnetism was studied on cobalt-doped α-Fe 2 O 3 particles, with special regard to the evolution of coercive fields as well as exchange bias fields. It was found that the coercivity of calcined sample fell into decline as temperature rose. Quite on the contrary, the sample prior to calcination exhibited a monotonical increment as increasing temperature. Further studies showed that lattice defects and voids in α-Fe 2 O 3 host, Co-doped α-Fe 2 O 3 colonies, FeOOH magnetic lattice, and CoFe 2 O 4 impurity phase were responsible for such significantly distinct magnetism evolution. The exhibited large coercivity beyond 10 kOe and pronounced exchange bias field of −660 Oe enabled us to gain deep insight into the transition metal doped magnetic semiconductor and to promote its full exploitation in magnetic-relevant applications. [ABSTRACT FROM AUTHOR]

Highlights • Fe 2 O 3 /CNF was synthesized by electrospinning coupled with hydrothermal method. • 1D and porous Fe 2 O 3 /CNF has good conductivity and specific electrocatalytic activity. • The DSSCs with Fe 2 O 3 /CNF-based CEs achieved a PCE of 7.48%. Abstract The exploration of low-cost and efficient counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) is of great significance in view of potential application of DSSCs. Herein, the Fe 2 O 3 /CNFs composites are synthesized by electrospin method and a facile hydrothermal method, and the composites of Fe 2 O 3 /CNFs is used as a low-cost counter electrode for DSSCs. Scanning electron microscopy measurement shows that Fe 2 O 3 nanoparticles have been evenly located on the exterior of CNFs, providing abundant catalytic active sites for triiodide reduction. The one dimensional CNFs has a high conductivity, which could effectively reduce the agglomeration of Fe 2 O 3 nanoparticles, thus increasing the specific surface area of the material and facilitating the rapid transmission of ions and electrons in the electrolyte. The synergistic effect of Fe 2 O 3 /CNFs composite leads to high electrocatalytic activity. Consequently, DSSCs devices constructed with an Fe 2 O 3 /CNFs composite based on CE afford a decent power conversion efficiency of 7.48%, higher than the expensive Pt CE based DSSCs (6.97%). [ABSTRACT FROM AUTHOR]

Graphical abstract A novel reliable strategy for the fabrication of nanoporous Ag films by dealloying Ag/α-Fe 2 O 3 nanocomposites as low-cost precursor alloy. Highlights • Nanoporous silver film was fabricated by dealloying a low-cost Ag/α-Fe 2 O 3 nanocomposite in dilute acid solution. • Nanoporous Ag film with different ligament size was synthesized by etching in different dilute acid solutions. • A uniform nanoporous Ag film with smaller ligament size was synthesized in dilute sulfuric acid and exhibited strong SERS performance. • The synthesized nanoporous silver film exhibited good SERS sensitivity, uniformity and reproducibility for detection of Sudan III. Abstract A facile and reliable method for fabrication of nanoporous Ag film as surface-enhanced Raman spectroscopy (SERS) substrates was developed by dealloying the low-cost Ag/α-Fe 2 O 3 nanocomposite in dilute acid solution. Influencing parameters such as different dealloying solutions, electrolyte concentration and dealloying time were optimized, and a uniform nanoporous Ag film of tunable and smaller ligament size was synthesized by etching the nanocomposite in sulfuric acid as a dealloying solution, while hydrochloric acid produced coarsened Ag nanoporous structures. Besides, the ligament size of the synthesized nanoporous Ag film increased with the electrolyte concentration and dealloying time. SERS activity of the as-synthesized nanoporous Ag film was evaluated using R6G as Raman probe, and the nanoporous Ag film with smaller ligament size exhibited strong SERS activity with a SERS enhancement factor of 7.47 × 106. The substrate exhibited good sensitivity and uniformity (RSD, 13.3%), and practical applicability for SERS detection of Sudan III, a synthetic organic dye banned as food additives, and achieved a detection limit of 0.5 μM. More importantly, the developed method ensures low-cost and reliable method of nanoporous materials fabrication from low-cost semiconductor based nanomaterials for applications in wide variety of fields. [ABSTRACT FROM AUTHOR]

Influenza virus is a common human pathogenic agent that has caused serious respiratory illness and death over the past century and in recent year. Treatment options against pandemic influenza strain A/H1N1 are very limited and unsatisfactory. Therefore we have developed iron oxide nanoparticles (IO-NPs) with particle size in the range of 10–15 nm against pandemic influenza strain A/H1N1/Eastern India/66/PR8-H1N1. Cell viability and anti-influenza activity was measured by MTT assay, plaque inhibition and quantifying viral transcripts using quantitative real-time PCR with Iron oxide nanoparticles in a dose- and time-dependent manner. 50% cell viability (TD 50) was observed at 4.25 pg ±.2 pg of Iron oxide nanoparticles. The percentage of plaque inhibition relative to the infection and the IC 50 (50% virus reduction) of PR8-H1N1strain (0.5 moi) were measured in vitro by the plate forming unit (pfu) in MA104 cells. Finding were observed at 01 pg after 72 h. The Antiviral activity determined by change in viral RNA transcripts within 24 h of virus infection by RT-PCR, 08 fold reductions in virus found when treated with Iron oxide nanoparticles Thus; it opens a new avenue for use of IP-NPs against virus infections. [ABSTRACT FROM AUTHOR]

Abstract A simple and novel method was developed at first time to enhance As (V) removal by zero valent iron (ZVI) and activated ZVI/Fe 3 O 4 media (AIM) through air injection at intervals. Fe (II) was essential to trigger As (V) removal by ZVI and AIM, and magnetite did not improve As (V) removal. In presence of 0.5 mM Fe (II) under anaerobic condition, 10 g L−1 ZVI and AIM showed same As (V) removal efficiency including percentage, capacity and rate of >99.999%, 3.0 mg/g ZVI/AIM and 0.013 mg As (V)/(g · min), respectively. Compared to the passivation of ZVI and AIM after one-time air injection, As (V) removal efficiency was significantly improved by intermittent air injection with increased air volume and injection frequency. After third time of 1.0 mL air injection at 30 min intervals, As (V) removal percentage and capacity remained same remarkable values as that under anaerobic condition, but total removal rate was further improved to 0.033 mg As (V)/(g · min). XPS results indicated that As (V) was completely reduced to As (III) and As (0) by Fe (0) under anaerobic condition, but quick adsorption/co-precipitation of As (V) followed by reduction to As (III) and As (0) by Fe (0) was the main mechanism under aerobic condition. This study suggests the addition of Fe (II) followed by simple air injection at intervals harnesses the reactivity of traditional ZVI for arsenic removal. Graphical abstract Image 102718 Highlights • Fe (II) was essential to activate ZVI and AIM systems to remove As (V). • ZVI and AIM showed high As (V) removal percentage, capacity and rate anaerobically. • As (V) removal efficiency was significantly improved by injecting air at intervals. • As (V) removal mechanisms under aerobic and anaerobic conditions were described. [ABSTRACT FROM AUTHOR]

The presence of wear debris in sliding contacts is often regarded as detrimental, since it can increase friction, induce abrasive wear, reduce actual lubricant film thickness and compromise lubrication systems. On the other hand, the presence of debris may be fundamental to the formation of a protective tribolayer, which can reduce friction and wear. This work investigates the effect of the presence of different iron oxides (F 2 O 3 and Fe 3 O 4) with different sizes on the unlubricated reciprocating sliding of tool steels. For that, sliding tests were carried out with and without the addition of iron oxides. The addition of Fe 3 O 4 particles (larger and softer) resulted in friction (15%) and wear (95%) reduction. Two main factors seem to be responsible for friction and wear reduction when Fe 3 O 4 particles were added into the contact. The first is the relative hardness of the debris in relation to the materials in contact. Since they are softer than the specimens and the counter bodies, they do not cause their severe abrasive wear, which is much more significant for the harder F 2 O 3 particles. The second is the relative size (RS) between the debris and the specimen surface topography. When RS is small, the debris get entrapped in the valleys of the specimen topography, thus not participating in the contact. On the other hand, for larger values of RS , the debris become active and therefore can participate in the formation of a protective tribolayer. • Dry reciprocating sliding tests were carried out with and without the addition of F 2 O 3 and Fe 3 O 4. • The presence of iron oxide particles improved tribological behaviour reducing friction and wear. • The addition of Fe 3 O 4 particles (larger and softer) resulted in friction and wear reduction. [ABSTRACT FROM AUTHOR]

The present study investigates the running-in behaviour of low alloyed C-steel tubings in NaCl brine under CO 2 corrosive environment. These corrosion conditions are those typically found in the oil industry. The corrosion of C-steel in CO 2 environment leads to the formation of an iron carbonate scale. This scale determines the frictional behaviour at the interface between tubing and coupling. However, the tubing surface can contain iron oxides, either as a consequence of the production process or due to the presence of O 2 in the environment. The role of iron oxides is addressed by investigating the running-in behaviour of tubings with and without oxide scale present, while the influence of iron carbonates is addressed by performing additional tests in distilled water under N 2 environment. The results show that the interaction between iron oxides and carbonates determines the running-in behaviour of the tubings. The presence of iron oxides impairs the lubricious properties of the iron carbonate scale. This causes an increase in shear stresses at the sliding interface, as evidenced by the severe plastic deformation of the substrate. As a consequence, the presence of iron oxides during running-in leads to a transition from mild to severe wear. • Presence of iron oxides leads to running-in with high friction and severe wear. • Iron oxides form a MML during running in. • Low friction requires formation of an iron carbonate layer. • The inhibition of iron carbonate formation leads to a factor 2 higher friction. [ABSTRACT FROM AUTHOR]

Abstract Fe 3 O 4 @C nano-adsorption was prepared by a simple one-step solvothermal synthesis method using Fe (NO 3) 3 、cyclodextrin as raw materials, meanwhile urea as an alkali source. The obtained samples were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, and Brunauer-Emmett-Teller. The adsorption behavior of the Fe 3 O 4 @C toward Cr (VI) and Congo red was also studied. The core-shell structure Fe 3 O 4 @C exhibited large specific surface area of 112.91 m2 g−1. The prepared Fe 3 O 4 @C samples demonstrated typical ferromagnetic behavior and high removal capacity in removing the toxic Cr (VI) ions and organic pollutant CR from wastewater, together with facile magnetic separability and good recyclability. Equilibrium adsorption performance was conducted by using the Langmuir and Freundlich model and Freundlich model could simulate the adsorption process of Congo red and Cr (VI) better. The maximum adsorption capacity of Cr (VI) and Congo red was 33.35 mg g−1 and 262.72 mg g−1 by calculation. [ABSTRACT FROM AUTHOR]