Search

The continuous phase transition phenomena and mechanism of pellets in the hydrogen blast furnace is achieved by dissecting the 40m3 hydrogen blast furnace. The results of the dissection reveal that the lumpy zone extends to the bosh of the hydrogen blast furnace (HBF), while it ends at about 2/3 of the stack in traditional blast furnace. The iron oxide (FeO x) began to appear in the upper stack, while the iron started to appear in the lower stack. The reduction rate and metallization rate at the bosh are measured at 95.18% and 95.54%. The content of ferrous oxide (FeO) decreases significantly (measured at 1.73% at the bosh), resulting in an increase in the melting point of the primary slag and a deterioration of its fluidity. FeO x formed in the upper stack continuously diffuses and merges into the gangue, which affects the subsequent transformation of FeO x. FeO x shows a preference for interacting with SiO 2 , CaO, and MgO, directly influencing the formation of slag in the cohesive zone. These findings offer valuable insights for numerical simulation and research on hydrogen-rich operation. • A 40 m3 experimental hydrogen-rich blast furnace is dissected. • The lumpy zone of hydrogen blast furnace extends to bosh. • The reduction rate and metallization rate at the bosh are 95.18% and 95.54%. • FeO x tends to react with SiO 2 to form high melting point substance. • A mechanism of iron and gangue transformation is proposed. [ABSTRACT FROM AUTHOR]

To achieve a coating density meeting the solid oxide fuel cell (SOFC) electrolyte requirements of high gas tightness and ionic conductivity, in this study, a new interface healing densification process based on a liquid-phase sintering induction mechanism was conducted on plasma-sprayed 8 mol% Y 2 O 3 -stabilized ZrO 2 (8YSZ) coatings. Using Fe 2 O 3 and Bi 2 O 3 as healing additives, metallurgical healing of unbound interfaces was achieved by impregnating the additives into the gap interfaces, followed by liquid-phase sintering at 1200 and 1050 °C. After healing, the YSZ coating exhibited a dense bulk-like microstructure with a significant reduction in the gas leakage rate by two orders of magnitude, and the oxygen ion conductivity of the coating was significantly increased. The YSZ coating healed with the Fe 2 O 3 additive showed an oxygen ionic conductivity nearly one order of magnitude higher than that of the as-sprayed coating, reaching more than 80% of the value of the high-temperature-sintered YSZ bulk. • A new interface healing process based on liquid-phase sintering was conducted on APS YSZ coatings. • The interface-healed YSZ coating exhibited a dense bulk-like microstructure. • The gas leakage rate of the interface-healed YSZ coating decreased by two orders of magnitude. • Ionic conductivity of the interface-healed YSZ coating reached > 80% of the sintered bulk. • The cell assembled with interface-healed YSZ-Fe 2 O 3 electrolyte achieved MPD of 1.04 W/cm2 at 800 °C. [ABSTRACT FROM AUTHOR]

This paper explores the important impact of Fe 2 O 3 on the synthesis, structure, hardness, and radiation shielding characteristics of Apatite–Wollastonite (AW) glass ceramics for bone implantation and shielding application. The prepared studied samples were prepared and the effects of Fe 2 O 3 addition on the synthesis process, density, and different physical and structural parameters comprehensively investigated. Additionally, the radiation shielding properties were determined by using PHITS simulation code and XCOM calculations for all samples. The results reveal that there is a significant impact of Fe 2 O 3 addition on density, hardness, and radiation shielding of AW glass ceramics. The Vickers hardness values were calculated as 547, 598, and 621 Hv in measurements under 0.1 kg load., the density values are found to be as 2.87, 3.07 and 3.28 g/cm3 for AW, Aw -1Fe, and Aw -2Fe, respectively. The highest linear attenuation coefficient in the AW- 2Fe is 0.096 cm−1, Aw -1Fe showed 0.084 cm−1 and AW gave 0.072 cm−1 at 6 MeV. This study underscores the pivotal role of Fe 2 O 3 as a multifaceted modifier in tailoring the properties of AW glass ceramics for bone implantation and other diverse applications extending from medical imaging to radiation and charged ions shielding. [ABSTRACT FROM AUTHOR]

This study investigated the effects of using ferric oxide nanoparticles (FO) and C2–C4 alcohols with diesel/biodiesel blend in a diesel engine. Optimum operating conditions were explored, and an engine speed of 1750 rpm was optimal. The concentration of FO was estimated to be 760 ppm, considering the best conditions for carbon nanotube (CNT) production. Ethanol was immiscible in diesel fuel; however, any biodiesel percentage in the blend made it miscible. The used engine was too small to run with a blend containing more than 3 % ethanol. Propanol and butanol were blended at the same ethanol concentration for comparative purposes. A blend with 30 % biodiesel (B30) was found to be the best diesel/biodiesel blend. This was detected by the best coefficient of variation (COV) with reasonable performance and emissions. Ferric oxide nanoparticles reduced COV and improved engine performance. The COV increased for tested alcohols. However, blending B30 with alcohols, especially butanol, improved thermal efficiency. FO and alcohol increased NOx emissions and decreased both CO and smoke opacity. They increased the peak pressure and the heat release rate while reducing the combustion duration. Nonetheless, no CNT traces were detected in the present study under any conditions. [ABSTRACT FROM AUTHOR]

The high-temperature oxidation behavior of Cr-Mn-Si alloyed steel by Fe 2 O 3 contained mold flux in high temperatures, and its effect on microstructure evolution were investigated in detail by TEM, EBSD, CLSM, SEM, and XPS. A novel oxidation mechanism was firstly revealed that the Fe 2 O 3 in mold flux melts during high temperatures plays a role of oxidizing alloyed steels by the released free oxygen ions (O2−) from the transformation of Fe 2 O 3 (Fe3+) to FeO (Fe2+). The formed oxidized dots within the oxide layer changed from SiO 2 and MnSiO 3 to MnCr 2 O 4 spinel phases by increasing the content of Fe 2 O 3 in the mold flux. Notably, the amorphous SiO 2 was discovered in the core region of MnSiO 3 phase due to its selective oxidative behavior in high temperatures. This research provides conclusive evidence that the small size MnSiO 3 oxides can be acted as a nucleation core for the refinement of austenite grains through in-situ observation. [ABSTRACT FROM AUTHOR]

By incorporating the dual ceramic elements TiB 2 /B 4 C, we investigated their impact on the mechanical properties, thermal properties, and friction performance of copper-based powder metallurgy materials, and elucidated the friction wear mechanism. Additionally, machine learning algorithms were employed to predict the friction coefficient and stability coefficient. The conclusions are as follows:With the increase in the TiB 2 /B 4 C ratio, the trend of mechanical properties initially increases and then decreases, with the optimum ratio being 5:3 for TiB 2 and B 4 C, exhibiting superior mechanical properties. Moreover, B 4 C enhances the thermal conductivity of copper-based friction materials more effectively than TiB 2. In terms of overall friction performance, the ratio of TiB 2 to B 4 C at 5:3 yields better frictional properties. The primary components of the friction surface friction film are CuO, Cu 2 O, Fe 2 O 3 , and B 2 O 3 , transitioning from a ceramic film to a metallic film as the TiB 2 /B 4 C ratio increases. The friction wear mechanism shifts from abrasive wear to severe fatigue wear as the TiB 2 /B 4 C ratio increases, accompanied by oxidative wear. Furthermore, an AdaBoost algorithm model was developed to effectively predict the friction coefficient and stability coefficient, with accuracies of 0.9993 and 0.8739, respectively. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate systematic studies on the influence of Fe 2 O 3 on the structural and optical properties of transparent B 2 O 3 –TeO 2 –Na 2 O glasses containing the different concentrations of Fe 2 O 3. The glasses were prepared via the standard melt quenching method, and the prepared glasses were characterized using, XRD, electron paramagnetic resonance (EPR), FTIR, and UV–visible spectroscopic techniques. Furthermore, we evaluated several physical properties of the glasses, including densities, molar volume, boron-boron separation, and oxygen packing density, with respect to the concentration of Fe 2 O 3 in the host glass matrix. It is observed that the density of the glasses and the average boron-boron distance found increase with Fe 2 O 3 concentration due to the modification in the glass network induced by the dopant ions. EPR spectra reveals the presence resonance signals at g ∼2.04 and g ∼4.26, hence it proves the existence of Fe3+ in distorted octahedral coordination and supported by UV–Vis absorption bands. The FTIR spectra revealed an increase in spectral intensity with the concentration of Fe 2 O 3. This was attributed to the formation of non-bridging oxygens through converting BO 4 units into BO 3 units, which Fe 2 O 3 mediated. The UV–visible spectral analysis showed a decreased energy band gap from 2.26 to 1.51 eV with increased Fe 2 O 3 concentration. Additionally, we determined the Urbach energy, refractive index, optical basicity, and electronegativity, which are presented in detail. [ABSTRACT FROM AUTHOR]

Blue, green, and khaki spinels were produced by self-propagating high-temperature synthesis (SHS) using Co 3 O 4 –ZnO–Mg(NO 3) 2 ·6H 2 O–Al(OH) 3 –Al, Ni 2 O 3 –ZnO–Cr 2 O 3 –Al(OH) 3 –Al, and Co 2 O 3 –Fe 2 O 3 –Al(OH) 3 –Al mixtures. The composition of the synthesis products was characterized by X-ray diffraction and IR spectroscopy. The oxides Co 3 O 4 , Co 2 O 3 , ZnO, Ni 2 O 3 , Cr 2 O 3 , Fe 2 O 3 , and aluminum hydroxide Al(OH) 3 were used for the synthesis. Fuel was provided by aluminum powder (ASD-4). The spinel-type ceramic pigments were synthesized using layer-by-layer combustion, which involves two parallel exothermic reactions: aluminum oxidation and aluminothermic reactions. The fast self-propagating reactions and high synthesis temperatures rapidly destroy the structure of Al(OH) 3 hydroxide in the starting mixture, producing gaseous reaction products that prevent the sintering of the spinels. The surface morphology of pigment powders and their composition was studied using a Quanta 3D 200i, FEI Co. scanning electron microscope and a Philips SEM 515 scanning electron microscope equipped with a local energy dispersive X-ray analysis (EDAX). The particle size of the synthesized spinels was approximately 1–5 μm. Colored spinels powders obtained by the SHS process can be used as ceramic pigments. [ABSTRACT FROM AUTHOR]

The widespread industrial use of styrene highlights the urgent need for detecting and monitoring its harmful gases. The innovation of this study lies in synthesizing uniform Fe 2 O 3 nanoparticles using Ginkgo biloba and calcining them with CuOHF to prepare nanostructured materials, enhancing the performance of gas sensors. The effects of varying α-Fe 2 O 3 additions and calcination temperatures on the structure and gas-sensitive properties of the composites were systematically investigated. The results revealed that the optimal operating temperatures of the CuO–10%Fe 2 O 3 -400 sensor were reduced by 80 and 50 °C, and its response to 100 ppm styrene at 200 °C was significantly enhanced by 3.2-fold and 4.2-fold, respectively, compared to the single Fe 2 O 3 and CuOHF sensors. It is particularly noteworthy that the sensor exhibits excellent detection performance at a 50 ppb styrene concentration, with a response value of 1.2. The lamellar structure of CuOHF serves as a precursor for CuO, thereby increasing the surface area of the sensor in contact with the gas. During the calcination process, the released gases contribute to the formation of a porous structure, which together improves the adsorption capacity and stability of the sensor. Additionally, the heterojunction formed by the calcination of CuO (p-type) and Fe 2 O 3 (n-type) enhances charge transfer and increases gas adsorption capacity, highlighting its potential as a gas sensor. This composite material exhibits good sensitivity and reliability in monitoring hazardous gases like styrene, underscoring the significant value of this study in environmental monitoring and safety control. [ABSTRACT FROM AUTHOR]

The permeability of the Fe Soft Magnetic Composite (SMC) materials need further improve to broaden their application prospect. This research work presents a novel high permeability SMC material which has a low core loss (P cv). The Fe particles formed an elongated strip shape structure through the ball milling process, and the high permeability Mn 0.5 Zn 0.5 Fe 2 O 4 ferrite phase was formed around the elongated strip shape Fe particles via a high temperature in-situ reaction process (ZnO + MnO + Fe 2 O 3 –Mn 0.5 Zn 0.5 Fe 2 O 4). While the added high resistive SiO 2 phase aggregated at the long strip shape Fe particle outer surface and effectively increased the resistivity of the SMCs. As the percentage of the Mn 0.5 Zn 0.5 Fe 2 O 4 ferrite coating increase, the permeability of the double layer coated SMCs gradually increased from 38 for the 1 wt% Mn 0.5 Zn 0.5 Fe 2 O 4 coated SMCs to 170 for the 18 wt% Mn 0.5 Zn 0.5 Fe 2 O 4 coated SMCs. The 3 wt% Mn 0.5 Zn 0.5 Fe 2 O 4 coated SMCs has the lowest core loss (P cv) of 86.9 W/kg at 10 mT, 500 kHz. [ABSTRACT FROM AUTHOR]

Perovskite oxides play a crucial role as catalysts in the oxygen evolution reaction (OER) owing to their distinctive structure and diverse physical and chemical characteristics. Currently, enhancing the electronic structure and specific surface area of the perovskite surface through strategic regulation poses a significant challenge in the advancement of perovskite catalyst development. Here, we propose a novel method for enhancing the OER activity of LaCoO 3 (LCO) perovskite through atomic doping and interface engineering. The La 0.6 Sr 0.4 CoO 3 –FeOOH (Fe-LSCO) composite exhibits a notable enhancement in electrocatalytic performance, manifesting a low overpotential of 296.3 mV for the oxygen evolution reaction (OER) at a current density of 10 mA cm−2, while maintaining a high level of activity for a duration of 120 h. The enhanced activity of Fe-LSCO can be attributed to oxygen vacancy defects and the increase of the active site caused by A-site-doping and amorphous nanosheets of FeOOH, which synergistic effect reduces the energy barrier for water dissociation. The highly disordered surface and high surface energy of amorphous FeOOH render it highly active. This study presents a viable interface engineering approach for manipulating the reconstruction of the active phase in high-performance perovskite-based electrocatalytic materials. [Display omitted] • Sol-gel and solution soaking treatment were used to fabricate Fe-LSCO. • The doping of Sr changes the spin state of Co ion. • The amorphous hydroxyl iron oxide can improve hydrophilicity and BET. • Fe-LSCO electrode demonstrates outstanding durability and stability. [ABSTRACT FROM AUTHOR]

Underground hydrogen storage (UHS) has been considered as an integral part of energy transition from fossil fuels to renewable sources. Porous aquifers can serve as typical sites for this purpose due to their worldwide distribution and huge storage capacity. However, the diverse microbial species that inhabit the aquifers are known to be able to catalyze in-situ biochemical reactions within the hosting rock. These reactions can normally lead to microbial consumption of hydrogen, microbial clogging of pore space and thus affect hydrogen injection and withdrawal rates as reported in the literature. So far, these phenomena have been widely reported but rarely quantified. In this study, we build a coupled hydrological-mechanical-chemical-biological (HMCB) multiphysics model to simulate these microbe-related processes during UHS in aquifers. The model consists of a complete set of partial differential equations to describe: (1) rock deformation; (2) water-hydrogen two-phase flow; (3) microbes and dissolved hydrogen transport; (4) mineral dissolution/precipitation; and (5) microbial activities involving adsorption/desorption and growth/decay. All these processes are linked together through the porosity/permeability models which consider the joint impacts of microbial clogging, mineral dissolution/precipitation and effective stress. This multiphysics model is verified against laboratory biochemical reaction data and microbial transport data. Then, the verified model is used to investigate the impacts of iron-reduction bacteria (IRB) activities on UHS in aquifers. Based on the simulation results, it can be concluded that (1) hydrogen saturation at the top surface of the aquifer is the greatest while microbial activities surrounding the injection well is stimulated the most; (2) microbial activities influence the initial few cycles of hydrogen injection and withdrawal but the impacts gradually diminish with the dissolution of Fe 2 O 3 ; (3) hydrogen recovery efficiency is degraded due to the combined effects of hydrogen consumption, water production and microbial clogging with the microbial clogging impact being the most significant; and (4) effective stress impacts aquifer permeability throughout UHS operations while microbial clogging influences it in the initial few cycles. For mineral dissolution/precipitation, the impact can be neglected. • Coupled multiphysics model has been developed to quantify the impact of IRB activities on UHS in aquifers. • Interactions among hydraulic-mechanical-chemical-biological processes are captured. • The model has been verified against laboratory microbial transport data and chemical reaction data. • Dependence of hydrogen recovery performance on various microbe-related parameters are evaluated. [ABSTRACT FROM AUTHOR]

α-Fe 2 O 3 has been regarded as an ideal n-type photoanode material due to its exceptional stability, environmental friendliness, optimal band structure (1.9∼2.2 eV), and valence band position (approximately 2.3 V). However, α-Fe 2 O 3 still faces challenges such as low absorption coefficient, poor conductivity, short carrier lifetime, low carrier mobility, facile recombination of photogenerated charges, and sluggish kinetics of water oxidation. To address these issues comprehensively and effectively, this study initially synthesized Ti-doped Fe 2 O 3 nanorods through doping and hydrothermal methods. Subsequently, a PdCoP amorphous layer was deliberately fabricated on the Ti:Fe 2 O 3 nanorods (TF) photoelectrode through facile solution impregnation and phosphorization treatment. The experimental results demonstrate that Ti doping effectively enhances carrier separation, leading to a photocurrent of 0.52 mA cm−2 at 1.23 V RHE , which is 2.08 times higher than the undoped counterpart. Moreover, upon further modification with the PdCoP amorphous layer, the photocurrent density of PdCoP/TF photoanode significantly increases under illumination, reaching 2.82 mA cm−2 at 1.23 V RHE , which is 11.28 times higher than pure Fe 2 O 3. Density functional theory (DFT) calculations performed at the interface between the amorphous layer and substrate indicate that surface modification of PdCoP on TF alters its surface electronic structure while reducing the energy barrier for oxygen evolution reaction (OER), thereby enhancing its performance in photoelectrochemical water splitting. [Display omitted] • The electronic structure of α-Fe 2 O 3 is optimized through Ti doping and modification of the amorphous layer. • The PdCoP/TF photoanode exhibits high efficiency in converting solar energy. • Revealing the active sites and mechanisms for water splitting through DFT calculations. [ABSTRACT FROM AUTHOR]

This study focused on developing self-cleaning matte ceramics based on polycrystalline hexaferrite for oil removal. The ceramics were glazed using glaze materials BaO, Fe 2 O 3 , ZnO, and TiO 2 with varying ZnO:TiO 2 ratios. The aim of this research was to determine the glaze composition that was able to provide the best self-cleaning/PA removal characteristics. After calcination at 1200°C, a polycrystalline hexaferrite compound formed, BaFe 12 ZnTiO 19. All ceramic samples demonstrated palmitic acid (PA) photodegradation, with CM3 (ZnO:TiO 2 ; 1:1) showing the highest efficiency. This efficiency correlated with CM3's lowest bandgap of 1.43 eV. The photodegradation of PA by CM3 follows first-order kinetics with rate constants of 0.0482 min−1 under UV irradiation and 0.0179 min−1 under visible irradiation. CM3 displayed exceptional durability, maintaining PA removal even after prolonged use, making it optimal for practical applications. [ABSTRACT FROM AUTHOR]

Previously, a strategy for doping MIEC perovskites ABO 3-δ with highly charged cations B5+ (Nb, Ta) and B6+ (Mo, W) was developed. The doping strategy is based on the idea that strontium ferrite/cobaltite-based perovskites are ferroelastic, whereas highly charged cations are ferroactive species. An increase in the concentration of the dopant leads to a reduction in the size of the domains of the ferroelastic phase down to the nanoscale. This resulted in the smearing of phase transitions with the formation of the highly conductive glassy state. Tantalum-doped lanthanum-strontium-ferrite perovskite (La 0.6 Sr 0.4 Fe 1-x Ta x O 3-δ , LSFTx) was prepared via solid-state reaction using chemically pure oxide powders of La 2 O 3 , SrCO 3 , Fe 2 O 3 , and Ta 2 O 5 , followed by calcination and sintering up to 1350 °C. The structural and surface properties were examined using X-ray diffraction and a scanning electron microscope. The original oxygen partial pressure relaxation (OPPR) method was used to study the kinetic properties of LSFTx. Continuous equilibrium phase diagram "T – pO 2 – δ" first obtained by oxygen release technique for composition LSFT3.5. Power law dependencies of the kinetic properties on the oxygen partial pressure are presented. [ABSTRACT FROM AUTHOR]

Copper-promoted iron oxides are commonly utilized in high-temperature water-gas shift (WGS) reactions. Although the promotional effect of Cu has been previously documented, the nature of the active sites for Cu/Fe 3 O 4 remains debated and the role of the crystallite size of Fe 3 O 4 has not been tackled. In this study, a wide range of Cu/Fe 3 O 4 catalysts were designed by hosting Cu species onto Fe 3 O 4 of two contrasting crystallite sizes (approximately 10 and 160 nm) and by utilizing different preparation methods (ammonia evaporation and deposition-precipitation). The evaluation of their catalytic WGS performances revealed a remarkable and previously undocumented phenomenon: the addition of Cu resulted in universal activity enhancements only for small Fe 3 O 4 crystals, while the larger analogues displayed decreased activity. This peculiar phenomenon can be explained by the creation of Cu–Fe 3 O 4 interfaces present in the iron oxides of small crystallite sizes. Thorough characterizations, such as advanced electron microscopic, in situ powder X-ray diffractions, in situ diffuse reflectance infrared Fourier transform spectroscopy, and computational studies, suggest strong electronic interactions between the different metal species, facilitated reductions of the individual oxides, and more favorable CO activation at the interfacial sites, all accounting for the promoted activity. [Display omitted] • Influence of Fe 3 O 4 crystallite size in water-gas shift reaction was examined. • Performance of Cu/Fe 3 O 4 in water-gas shift reaction was studied. • The formation of Cu–Fe 3 O 4 interfaces existed on small Fe 3 O 4 crystals. • Promotional effect of Cu was only found on small Fe 3 O 4 crystals. [ABSTRACT FROM AUTHOR]

The study of the cementitious material activity of industrial solid wastes is a key issue in the comprehensive utilization of its green building materials. In this study, mechanical activation was used to prepare cementitious materials from vanadium-titanium iron ore tailings (VTIOT) as the main raw materials, and the effects of grinding time, the key parameter, on the grinding characteristics of VTIOT, the mechanical properties of the VTIOT cementitious material, and the hydration mechanism were investigated by means of surface area analysis, particle size analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), alkali leaching, mechanical testing, hydration heat analysis, and thermogravimetric analysis (TGA). The results show that: the grinding time and specific surface area of VTIOT exhibit a linear correlation. Prolonging the grinding time, the fractal dimension of the particles gradually increases. The activity of Si4+ and Al3+ elements increases rapidly, reaching a Si4+ and Al3+ content of 96 mg·L−1 at 90 min of grinding. With a VTIOT mixing amount of 30 %, a mortar paste ratio of 1:3, and a water cement ratio of 0.5, the 50 min ground VTIOT mortar demonstrates 7 d and 28 d compressive strengths of 29 MPa and 38.7 MPa, corresponding to the highest values of the activity index, measured at 71.4 % and 75.2 %, respectively. Under standard curing conditions, the hydration products of cementitious materials at 7 d are ettringite (AFt), calcium silicate hydrate (C-S-H), alumina, ferric oxide, monsulfate (AFm), calcium hydroxide (Ca(OH) 2), and calcium silica (CS). In the hydration process of 7 d, the exothermic peak and exothermic amount of the 50 min VTIOT cementitious materials are greater than those observed for other grinding times, but lower than those of pure reference cement. [ABSTRACT FROM AUTHOR]

Rose (Rosa chinensis) is subjected to various biotic and abiotic stresses. In this study, rose leaves with blight symptoms were collected and based on microscopic, morphological, and genetic analyses, the disease-causing pathogen was identified as Aspergillus niger. To our knowledge, this is the first report of leaf blight of R. chinensis in Pakistan. To control this disease, iron oxide nanoparticles (Fe 2 O 3 NPs) were synthesized in the seed extract of Trachyspermum ammi. Suitable formation of synthesized Fe 2 O 3 NPs was tested using reliable techniques. Fourier transformed infrared (FTIR) spectrum of Fe 2 O 3 NPs determined the presence of reducing agent like alcohol, alkyl halide and amine on the surface of NPs. X-Ray diffraction (XRD) analysis depicted crystal-like nature and size (41 nm) of NPs, while scanning electron microscopy (SEM) depicted their spherical shape. Sharp Fe and O peaks were observed by energy dispersive X-ray (EDX) analysis. All concentrations of Fe 2 O 3 NPs (0.25, 0.5, 0.75, 1 and 1.5 mg/ mL) inhibited mycelial growth, in vitro and the greatest inhibition (88.9 %) was observed at 1.0 mg/ mL concentration. SEM micrographs showed severe shrinking and structural decomposition of mycelia at this concentration. In pot experiment, Fe 2 O 3 NPs adeptly controlled blight disease of rose leaves by improving various physiological and biochemical attributes and superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities. Findings of Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) showed the higher expression of RcWRKY29 by the application of Fe 2 O 3 NPs, depicting its probable role in plant defense mechanism. These results proved that the application of Fe 2 O 3 NPs can efficiently prevent the spread of blight disease. [Display omitted] • Fe 2 O 3 nanoparticles were used to control leaf blight of Rosa chinensis. • Application of NPs increased the activity of antioxidant enzymes. • Interaction of NPs also up-regulated the expression of RcWRKY29. • qRT-PCR and KEGG pathway demonstrated plant-defense mechanism. • These NPs can efficiently prevent the spread of blight disease.s. [ABSTRACT FROM AUTHOR]

Glioma is an aggressive malignant brain tumor with a very poor prognosis for survival. The poor tumor targeting efficiency and tumor microenvironment penetration barrier also as troubles inhibited the effective glioma chemotherapy. Here, we design a core-shell structure cascade amplified hybrid catalytic nanopotentiators CFpAD with DM1 encapsulated to overcome the glioma therapeutic obstacles. NIR laser-based BBB penetrating enhances the tumor accumulation of CFpAD. When CFpAD, as the cascade amplified drug, is treated on the cancer cells, the bomb-like CFpAD releases gold nanoparticles as glucose oxidase (GOx) and ferric oxide nanoparticles (FNPs) as peroxides (POx) after blasting, producing ROS via a cascade amplification for tumor cell apoptosis. Gold nanoparticles can rest CAFs and reduce ECM secretion, achieving deep penetration of CFpAD. Moreover, CFpAD also cuts off the nutritional supply of the tumor, reduces the pH value, and releases free radicals to destroy the cancer. The glioma cell viability was significantly decreased through DNA damage and ROS aggregation due to the DM1-based chemotherapy synergistically combined with interventional photothermal therapy (IPTT) and radiotherapy (RT). This domino cascade amplified loop, combined with starvation therapy with IPTT and RT, has good tumor penetration and outstanding antitumor efficacy, and is a promising glioma treatment system. Schematic illustration of a combined interventional therapy strategy for enhancing glioma penetration and CFpAD anti-tumor efficacy through cascade amplification. (A) Preparation of FNCp, FpA, and CFpAD. (B) The blood-brain barrier is temporarily opened with IPTT. (C) Hybrid nanopotentiators reduce interstitial fluid pressure through CAF quiescence and increase the permeability of therapeutic agents. (D) Hybrid nanopotentiators consume glucose to reduce tumor pH, produce oxygen to improve tumor hypoxia, and generate ROS to inhibit tumor proliferation. [Display omitted] • Dual cascade amplified hybrid nanopotentiators are designed for glioma. • Hybrid nanopotentiators can not only enhance the deep penetration of nanoparticle, but also enhance its catalytic ability. • Nanopotentiators have effective antitumor activity. [ABSTRACT FROM AUTHOR]

Solar energy absorption and storage of integrated ceramic materials is both the absorption of sunlight and storage of sunlight into thermal energy functional materials. In this paper, the effect of Fe 2 O 3 on the solar absorptivity, thermal storage properties, sintering temperature, and physical properties of mullite-based thermal storage ceramics was investigated. The results show that the absorptivity and thermal storage density of the sample AF4 (Bauxite:50 wt%, Clay:50 wt%, Fe 2 O 3 :11 wt%) after sintering at 1420 °C are 87.2% and 1116.5 kJ kg−1, respectively; and the unit volume of the AF4 sample can provide the power grid with 918.01 kW h of electricity, save 112.91 kg of coal, and reduce 361.33 kg of CO 2 emission. This study systematically elucidated the mechanism of the enhancement of sample absorption caused by Fe3+ doping-induced changes in substrate color, reduction in material forbidden bandwidth, and lattice anharmonic vibration effect, in addition to comprehensively evaluating the feasibility of the optimal AF4 sample for use in solar energy absorbing and storing integrated ceramic materials. [ABSTRACT FROM AUTHOR]

Nanosized composite materials based on BaTiO 3 with 0.5 % and 1 % Fe 2 O 3 were prepared by the sol-gel method and subsequent heat treatment. This work showed that increasing the content of iron(III) oxide in a heterostructured material affects the bleaching of the dye rhodamine B upon irradiation with visible and ultraviolet light. The highest photocatalytic activity was observed on the solid surface of the samples in an air environment under both visible and UV irradiation. The BaTiO 3 /0.5 % Fe 2 O 3 sample was found to be most effective in an air environment when irradiated with an artificial visible light source. The increase in efficiency could be due to the best separation of charge carriers at the interface between the barium titanate and iron(III) oxide structures and the highest concentration of the resulting radical anions. An increase in the mass fraction of Fe 2 O 3 led to a decrease in the efficiency of the nanoscale composite photocatalyst, which was due to a greater recombination of charge carriers. [ABSTRACT FROM AUTHOR]

In order to develop a sensitive, stable and cheap gas sensor for detection of triethylamine (TEA), the bimetal oxide of ZnFe 2 O 4 with α -Fe 2 O 3 heterojunctions with different proportions were synthesized and reduced graphene oxide (rGO) modified on heterojunctions by hydrothermal and chemical precipitation methods. The gas-sensing tests to TEA showed that the 6 α -Fe 2 O 3 /ZnFe 2 O 4 -rGO (0.8 wt%) composite has highest response reaches 10.48–20 ppm TEA with a rapid response time of 29 s, an impressively low detection limit of 0.145 ppm and reliable stability within 32 days at operating temperature of 143 °C. Compared with reported before, it has higher response at lower operating temperature and lower concentration of test gas. The enhancing mechanism is attributed to the formation of semiconductor heterojunction, which makes the resistance of composite in air further increase and further decrease in TEA compared with α -Fe 2 O 3 due to generating an additional electron depletion layer in the heterojunction interface, while rGO accelerates the electron transfer and provides more active sites for gas adsorption. A bimetal ternary oxide of ZnFe 2 O 4 is introduced to prepare the composite of 6 α -Fe 2 O 3 /ZnFe 2 O 4 -rGO (0.8 wt%) via low-cost chemical precipitation and hydrothermal methods. The novel composite has excellent gas sensing to TEA, which is due to the formation of heterojunctions and the modification of rGO. [Display omitted] • The novel composite of 6 α -Fe 2 O 3 /ZnFe 2 O 4 -rGO (0.8 wt%) was simply synthetized. • The composite response is 2.62 times of α -Fe 2 O 3 , and is rapid and stable. • The improvement is attributed to the formation of heterojunction and rGO modification. [ABSTRACT FROM AUTHOR]

Metal-halide perovskite (MHP) nanocrystals (NCs) have unique advantages in the gas sensing field, but the poor stability restricts their widespread applications. In this work, the CsPbBr 3 @Fe 2 O 3 heterojunction NCs were synthesized successfully by simple solution process and subsequent surface modification strategy for constructing a gas sensor. The Fe 2 O 3 shell layer was obtained through thermal decomposition of acetylacetone iron (AAI) at 400 °C. The resulting CsPbBr 3 @Fe 2 O 3 heterostructured NCs exhibit a higher gas-sensing performance to H 2 S than pure CsPbBr 3 and Fe 2 O 3 , respectively. Upon exposure to 10 ppm H 2 S, the response value of 4.12 was obtained at a moderate working temperature of 350 °C, while the response was fast both in terms of response time and recovery time, i.e. , 1.84 s and 24.20 s, respectively. This might be the best performance for MHP sensors, to the best of our knowledge. The excellent gas-sensitive response might be attributed to the formation of a heterojunction which promotes the electron migration from CsPbBr 3 to Fe 2 O 3. [ABSTRACT FROM AUTHOR]

Element substitution is an important means of preparing high-performance microwave absorbing materials by adjusting their physicochemical properties. The sol-gel method is employed as the primary technique in this study to synthesize a range of Ca 2- x La x Fe 2 O 5 (x = 0, 0.1, 0.2, 0.3) iron oxide materials by regulating the quantity of La element added. The Ca 1.8 La 0.2 Fe 2 O 5 has a minimum reflection loss (RL min) of −41.64 dB at a thickness of 2.2 mm, with an effective absorption bandwidth (EAB, RL ≤ −10dB) of 3.36 GHz. At an ultra-thin thickness of 1.8 mm, the RL min ＝－35.62 dB, and the effective absorption bandwidth is 4.48 GHz (almost occupying the entire Ku band). Ca 1.8 La 0.2 Fe 2 O 5 has the potential to become a new high-performance microwave absorbing material. The electromagnetic (EM) simulation results show that the sample had excellent radar cross-section reduction ability over a wide range of incident angles. This work provides guidance and ideas for the design and application of Ca 2 Fe 2 O 5 in electromagnetic wave (EMW) absorption. [ABSTRACT FROM AUTHOR]

This study aims to investigate sawdust-based activated carbon (AC) as catalyst, and as catalyst support for Fe and W in H 2 production by H 2 S decomposition. Activated carbon was prepared with the chemical agent phosphoric acid. The wet impregnation method was used in the preparation of sawdust-based AC supported Fe and W containing catalysts. Commercial mesoporous activated carbon was also used for comparison purposes as catalyst support. N 2 adsorption-desorption isotherms of AC showed the presence of both micro/mesoporosity. ICP-OES analyses revealed the phosphorus in the structure of all prepared catalysts. Raman, DTA profiles, and XRD patterns of AC and CMC showed that AC and CMC have amorphous and graphite carbon, respectively. The higher H 2 S conversion values obtained with AC-supported catalysts compared to CMC-supported catalysts can be attributed to the presence of oxygenated phosphorus in the structure of AC. XPS analysis revealed the presence of WO 3 in fresh 10W@AC, and Fe 2 O 3 in fresh 10Fe@AC. After the reaction, XPS analyses showed the formation of WS 2 on the 10W@AC catalyst, while it revealed the presence of elemental sulfur and sulfate structures on the 10Fe@AC catalyst. In catalysts containing Fe and W, it is observed that metal-sulfide compounds formed on the surface and in the bulk phase during reaction, as well as phosphorus compounds, may have catalytic activity. H 2 S conversions over AC and AC-supported catalysts were close to the thermodynamic equilibrium conversion value. To determine the possible product distribution during reaction, the reactor exit stream was analyzed by an online connected FTIR spectrometer. FTIR spectra indicated the formation of CS 2 , CO, and some CO 2 in the reactor exit stream using AC and AC-supported Fe and W catalysts. The activity test results showed that activated carbon prepared by phosphoric acid and activated carbon-supported Fe and W are promising catalysts for H 2 production via H 2 S decomposition. [Display omitted] • Activated carbon, Fe, W catalysts show high and stable activity in H 2 production. • 89% of the equilibrium conversion was achieved with all catalysts at 800 °C. • After the reaction, FeS and WS 2 were formed as a result of the structural change. • Besides the H 2 production by H 2 S decomposition, CS 2 and CO were also formed. [ABSTRACT FROM AUTHOR]

SiO 2 insulator and Fe 2 O 3 dopant was simultaneously used to modify the crystalline phase, morphology and electric properties of LaMnO 3 ceramics. Results show that there are several merits after modification. On the one hand, the addition of SiO 2 is demonstrated to have multifunction to the LaMn 1-x Fe x O 3 (0 ≤ x ≤ 0.5) (LMFO) ceramics. After adding SiO 2 , the surface of LMFO ceramics tend to be flat, the degree of densification increases, the porosity decreases, and the pores almost disappear. Meanwhile, the resistance drift rate of LaMnO 3 with SiO 2 is reduced and the aging stability is improved. In addition, the crystalline structure of LMFO ceramics transform from hexagonal perovskite phase (x ≤ 0.2) to cubic perovskite phase (x ≥ 0.25) along with the Fe-doping contents increase. Moreover, the grain size decreases and the grain boundaries increase with the increase of Fe content. X-ray photoelectron spectroscopy (XPS) spectra show that both the Mn4+/Mn3+ ratio and the oxygen vacancy concentration decrease with increasing Fe content. Resistivity ρ 25°C raised from 2.84 Ω cm to 65.38 Ω cm, and material constant B 25/50 increased from 139.36 K to 1751.78 K. Fe doping significantly improves the stability of LMFO ceramics, and the minimum value of resistance drift rate is 0.168 % after aging at 125 °C for 500 h. The above results confirm that the SiO 2 modified LMFO ceramic is a high stability negative temperature coefficient (NTC) thermistor. [ABSTRACT FROM AUTHOR]

This work investigates the behavior and properties of corundum and mullite ceramics at high temperatures and during very long exposures in a controlled atmosphere. The motivation of the work lies primarily in advanced applications in nuclear energy technology, specifically in the search for materials for helium-cooled reactors of the 4th generation. The studied ceramic samples Al63, Al70, Al76, Al96, Al100, where the number indicates the mass percentage of Al 2 O 3 , were exposed for 1000 h at a temperature of 900 °C in gaseous atmospheres of helium, nitrogen and air. The properties of the exposed and unexposed samples were evaluated by measuring the bending strength at room temperature (CMOR), hot modulus of rupture at high temperature (HMOR), and isothermal creep, BET method, and using electron microscopy. The color changes induced by the reducing atmosphere and temperature were also interpreted using a simple thermochemical model. The CMOR measurement results show that all ceramic samples do not significantly change their properties due to long-term exposure. The detected deviations in the exposed samples from the unexposed ones can be considered random caused by the inherent heterogeneous structure. A similar conclusion also applies in the case of the HMOR measurement results, except for the results for the Al63 sample, where the drop in the strength of the exposed samples by approx. 37 MPa (20 %) may be related with the highest proportion of polyvalent oxide admixtures of all studied ceramics, i.e. 1.01 wt % Fe 2 O 3 and 0.52 wt % TiO 2. The change in color indicates that the iron and titanium present are being reduced. However, none of the conducted experiments indicate that changes in the redox state associated with the formation of oxygen vacancies would significantly reduce strength at high temperatures or increase creep in mullite ceramics. [ABSTRACT FROM AUTHOR]

In this study, iron oxide nanoparticles (IONPs) were employed as an efficient chemical additive to enhance the Chlorella sp. biomass growth and lipid content. A novel strategy was developed to promote biomass growth and lipid content. Treatment with 20 mg/L followed by an additional 40 mg/L concentration of IONPs increased biomass and lipid content of Chlorella sp. by 53% and 67%, respectively, compared with the control. The hydrolyzate of 20 mg/L IONPs treated biomass residues obtained after combined hydrolysis showed maximum reducing sugars content of 41% dry cell weight (dcw), which was further used as substrate for dark fermentative hydrogen production mediated by Enterobacter aerogenes. The optimized concentration of IONPs supplementation in the dark fermentation system yielded 2.6 mol H 2 /mol sugar with acetate as predominant end metabolite. Hence, the present study demonstrated that the IONPs supplementation was a suitable chemical catalyst for biomass and biofuel production. [Display omitted] • 20 mg/L iron oxide nanoparticle supplementation enhances Chlorella sp. biomass • 60 mg/L iron oxide nanoparticle supplementation enhances Chlorella sp. lipid content • Biomass residues pretreated with combined hydrolysis produces 41% total reducing sugar • Iron oxide nanoparticle supplementation enhances dark fermentative hydrogen production • 30 mg/L iron oxide nanoparticle supplementation produces 2.6 mol H 2 /mol sugar [ABSTRACT FROM AUTHOR]

The Tibetan Plateau, known as the "Third Pole", is currently in a state of perturbation caused by intensified human activity. In this study, 56 samples were obtained at the five sampling sites in typical area of Lhasa city and their physical and chemical properties were investigated by TEM/EDS, STXM, and NEXAFS spectroscopy. After careful examination of 3387 single particles, the results showed that Fe should be one of the most frequent metal elements. The Fe-containing single particles in irregular shape and micrometer size was about 7.8% and might be mainly from local sources. Meanwhile, the Fe was located on the subsurface of single particles and might be existed in the form of iron oxide. Interestingly, the core-shell structure of iron-containing particles were about 38.8% and might be present as single-, dual- or triple-core shell structure and multi-core shell structure with the Fe/Si ratios of 17.5, 10.5, 2.9 and 1.2, respectively. Meanwhile, iron and manganese were found to coexist with identical distributions in the single particles, which might induce a synergistic effect between iron and manganese in catalytic oxidation. Finally, the solid spherical structure of Fe-containing particles without an external layer were about 53.4%. The elements of Fe and Mn were co-existed, and might be presented as iron oxide–manganese oxide–silica composite. Moreover, the ferrous and ferric forms of iron might be co-existed. Such information can be valuable in expanding our understanding of Fe-containing particles in the Tibetan Plateau atmosphere. [ABSTRACT FROM AUTHOR]

An estimated 30 % (∼11 million metric tons/year) of copper slag is still landfilled globally. Fayalitic copper slags are well-characterized, and they can be recycled into multiple safe end-products. Conversely, the major type of copper slag produced in Europe is lead-rich and warrants a deep understanding of phases present in it, properties, adverse environmental implications, and potential recycling strategies. The objective of this study is to thoroughly investigate such industrial slags by XRF, XRD, Mössbauer spectroscopy, SEM-EDS, novel automated image analysis using Aphelion, hot stage microscopy (HSM) and assess prospects for their valorization. These industrial slags were found to contain 26.1–50.5 wt% PbO, 3.4–5.4 % As 2 O 5 (both hazardous solid wastes), 5.7–42 % CuO (present partly as Cu 2 O, an irritant), 3.2–18.2 % Fe 2 O 3 , 14–15.9 % SiO 2 and oxides of chromium, cobalt (both carcinogenic), zinc and nickel (both toxic to aquatic life). The limitation of Rietveld XRD for glass quantification was overcome by newly-developed automated SEM-image processing which revealed that all three slags consisted of a lead silicate glass (36.3–65.8 vol%). Strikingly, rarely published arsenic- and lead-based compounds like (Ca,Pb) 4 As 2 O 9-x , (Ca,Cu) 2 PbO 4-x and Pb 3 Ca 2 Si 3 O 11 were found when slag's PbO/CuO was 0.6, and Ca 3 As 2 O 8 -Pb 2 SiO 4 formed when PbO/CuO equaled 9. The challenge of toxicity and landfilling can be overcome as these slags have high potential to be used for recovery of copper, cobalt, and lead. Radioactive waste immobilization glasses, gamma-ray shielding concrete and glass-ceramic consumer products may also be prepared from them. HSM revealed that a higher PbO/CuO ratio results in lower melting point and smaller melt contact angle indicating such slag can be useful for manufacturing recycled ceramics but corrosive towards refractories in copper converter. [ABSTRACT FROM AUTHOR]

• Activated persulfate systems with Fe-based catalysts in laboratory are reviewed. • The persulfate system activated by iron ore catalysts was introduced. • The advantages and disadvantages of two types of catalysts were discussed. • The mechanism of removing organic pollutants was evaluated. • The research direction of Fe-based catalyst/PS/ pollutant system was proposed. Heterogeneous iron-based catalysts have drawn increasing attention in the advanced oxidation of persulfates due to their abundance in nature, the lack of secondary pollution to the environment, and their low cost over the last a few years. In this paper, the latest progress in the research on the activation of persulfate by heterogeneous iron-based catalysts is reviewed from two aspects, in terms of synthesized catalysts (Fe0, Fe 2 O 3 , Fe 3 O 4 , FeOOH) and natural iron ore catalysts (pyrite, magnetite, hematite, siderite, goethite, ferrohydrite, ilmenite and lepidocrocite) focusing on efforts made to improve the performance of catalysts. The advantages and disadvantages of the synthesized catalysts and natural iron ore were summarized. Particular interests were paid to the activation mechanisms in the catalyst/PS/pollutant system for removal of organic pollutants. Future research challenges in the context of field application were also discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Blast furnace slag glass–ceramics were prepared by melting using rare-earth-containing blast furnace slag (REBFS) as the main raw material and Fe 2 O 3 and Cr 2 O 3 as composite nucleating agents. By adding different TiO 2 contents, the study comprehensively revealed the effects of high field strength ions on the glass network structure, crystalline properties, elemental distribution and physicochemical properties. Raman spectroscopy and differential scanning calorimetry revealed that TiO 2 acted primarily as a network modifier in the glass network. The appropriate TiO 2 content disrupted the glass network, decreasing the crystallization activation energy (E C) of the glass–ceramic. However, excess TiO 2 repaired the network structure, thereby increasing the E C. The combined effect of the Cr and Ti substantially improved the crystallization characteristics of the glass-ceramics. Cr 2 O 3 induced the formation of spinel, which promoted the crystallization of the main crystalline augite phase. The self-aggregation of the high field strength Ti4+ ion induced the formation of a titanium- and cerium-containing titanite phase, which also contributed to grain refinement. This titanite phase effectively increased the Vickers hardness and acid and alkali resistances of the glass-ceramics to 9.16 GPa and over 98.5 %, respectively. The excellent physicochemical properties render REBFS glass–ceramics as being promising materials for various construction applications. This research provides theoretical support for comprehensively utilizing blast furnace slag and provides theoretical guidance for preparing slag glass–ceramics possessing desirable physicochemical properties. [ABSTRACT FROM AUTHOR]

The study revealed a correlation between the cytotoxicity and antioxidant activity of iron oxide nanopowders produced by the radiation-chemical method and the choice of precursors (iron (III) nitrate or iron(II) sulfate), and the temperature of pre-annealing of the synthesized product, and also irradiation with accelerated electrons. Notably, high and lowabnormal cytotoxicity of aqueous suspensions of samples S300 and S400, respectively, annealed at temperatures of 300 and 400 °C, was observed for the first time at all concentrations (0.1–1.0 ml/mg). The likely cause of this abnormal cytotoxicity was identified as alterations in the textural and structural properties of NP after annealing.Furthermore, a significant impact of electron beam irradiation on the antibacterial and antioxidant properties of both unannealed and annealed iron oxide NP was discovered with irradiated samples exhibited lower cytotoxicity compared to non-irradiated ones. Additionally, the deposition of nanosilver on the surface of iron oxide powders was found to significantly influence their biological properties, with the survival of Vero cell cultures being dependent on the composite concentration in the aqueous suspension. A study of the oxidative stress of composites based on iron oxides coated with silver showed that they significantly increased cell viability, and at a concentration of 1 mg/ml provided complete mitigation of oxidative stress in cells. • The cytotoxicity of iron oxide nanopowders is dependent on electron irradiation. • The sample of iron oxide annealed at 400 °C showed an unusually high level of cytotoxicity. • Cytotoxicity of iron oxide nanopowders may depend on silver coating. • Silver coating on iron oxide has a compensatory effect on oxidative stress in cells. [ABSTRACT FROM AUTHOR]

In this study, the visible light photocatalytic activities of the ZnO and ZnO/Fe 2 O 3 structures were investigated. Anodization of Zn plates to obtain ZnO nanowires was carried out by applying 35 V between 1 and 30 min durations. Fe 2 O 3 layers were coated on initially obtained ZnO nanowires through a sol-gel spin-coating process. All samples were examined for morphological, structural, optical, and photocatalytic activities in detail. The results showed that the conducted anodization process was successful where up to micrometer-length nanowires were obtained. SEM images confirmed the presence of Fe 2 O 3 deposits surrounding the nanowires, while UV and visible absorption spectra indicated increased absorption due to Fe 2 O 3 , leading to enhanced photocatalytic performance. The best-performing ZnO nanowire anodized for 5 min almost doubled its photocatalytic activity after Fe 2 O 3 coating, in which an apparent reaction rate of 12.24 × 10−3 min−1 and degrading 90.32 % of the initial MB concentration was recorded. [ABSTRACT FROM AUTHOR]

In this study, the preparation, physical characteristics, microstructural attributes, and fast neutron (FN) removal parameters of apatite-wollastonite (AW)-containing GCs doped with 10 % SiO 2 , Fe 2 O 3 , and TiO 2 were reported. Glass-ceramics containing the AW crystal structure within the SiO 2 –CaO–Al 2 O 3 –MgO–P 2 O 5 –CaF 2 glass system were prepared and doped with 10 % SiO 2 , Fe 2 O 3 , and TiO 2 by weight. The microstructural and chemical evolution of the glass-ceramics were studied using SEM/EDS. The density and Vicker hardness of the samples were experimentally evaluated, while the fast neutron removal cross-sections (Σ R) were computed using standard equations. The SEM micrograph showed densely crystallised and crack-free surface surfaces. Silicon and titanium additions did not cause a significant increase in density. However, Fe doping had a higher effect on density. The values of Σ R for pristine, SiO 2 , TiO 2 , and Fe 2 O 3 -doped AW were found to be 0.0796 cm−1, 0.0832 cm−1, 0.0869 cm−1, and 0.0904 cm−1, respectively. Compared to some other materials, such as polymers, AW-10Fe showed better attenuation for fast neutrons. The investigated ceramics could be used in tissue engineering and fast neutron moderation functions. [ABSTRACT FROM AUTHOR]

Multifunctional superparamagnetic magnetite/hydroxyapatite (Fe 3 O 4 /Ca 10 (PO 4) 6 (OH) 2 or MHAp) nano-composites were synthesized via a facile two-step co-precipitation method at room temperature. These magnetic nano-composites underwent heat treatment at various temperatures ranging (400°, 600°, and 900 °C), which were subsequently utilized as nanosorbents for removing Pb2+ ions. The XRD data revealed that both the magnetite and hydroxyapatite synthesized were in a pure phase. In the Fe 3 O 4 /HAp composites, there was an augmentation in the intensity peak of hydroxyapatite observed up to 600 °C. However, at 900 °C, a calcium iron phosphate phase emerged, and magnetite (Fe 3 O 4) transitioned into the hematite (Fe 2 O 3) phase. Elevating the heat treatment enhanced the crystallinity of the developed Fe 3 O 4 /HAp composites while diminishing the surface area. The prepared nanocomposites exhibited high adsorption efficiency across a wide pH range, with an optimal pH of 5.5. Notably, the adsorption rate of Pb2+ reached 94 % within the first 5 min, with complete metal adsorption progressively at 60 min. The kinetic and isotherm analysis of the adsorption process revealed that pseudo-second-order model and Langmuir model agreed well with the adsorption process. Also, FAH 0 demonstrated the highest adsorption capacity (263.2 mg/g) for Pb2+ ions. Furthermore, the Fe 3 O 4 /HAp composite NPs exhibited remarkable recyclability even after five cycles of reuse; retaining an efficiency of over 96 %, and allowing for easy separation without a significant loss of adsorption efficiency. The results of the current desorption study underscore the promising practical applications of these nano-composites in decontaminating aqueous media. [ABSTRACT FROM AUTHOR]

In this study, ultra-small nickel nanoparticles on NiFe 2 O 4 (Ni@NiFe 2 O 4) and Ni@NiFe 2 O 4 /ZnO magnetic nanocomposites were synthesized and utilized for the solar light-driven photocatalytic degradation of cefadroxil. The drug cefadroxil is widely used to treat bacterial infections and cefadroxil is a non-biodegradable pharmaceutical compound detected in the groundwater sources because of its low removal efficiency. The Raman active phonon at 540 cm−1 confirms the presence of Ni nanoparticles at the surface of NiFe 2 O 4 /ZnO. DR-UV-Vis analysis exhibited surface plasmon resonance at 350 nm for ultra-small nickel nanoparticles. The observed optical bandgap values for Ni@NiFe 2 O 4 and NiFe 2 O 4 /ZnO are 1.2 eV and 2.43 eV, respectively. Which indicates that these magnetic nanocomposites can be utilized for the mineralization of cefadroxil (β-lactam antibiotic) under ambient environmental conditions. The efficiency was determined by the direct solar light driven photocatalytic oxidation of cefadroxil in the presence and absence of peroxymonosulphate (PMS). The experimental findings exhibits that ∼95 % of cefadroxil (CDL) was eliminated by the ultra-small Ni@NiFe 2 O 4 /ZnO within 60 min (k = 7.5 × 10−4 s−1) of direct solar light irradiation. Further, the addition of PMS enhanced the photodegradation to achieve 100 % cefadroxil oxidation within 40 min (k = 25 × 10−4 s−1) of direct sunlight. The efficiency of the nanocatalyst was compared with controlled experiments and was found to be Fe 2 O 3 < ZnO < TiO 2 (P25) < Ni@NiFe 2 O 4 < Ni@NiFe 2 O 4 /ZnO under absence and presence of PMS. Moreover, ultra-small Ni@NiFe 2 O 4 /ZnO nanophotocatalyst were stable up to 3 consecutive cycles. [ABSTRACT FROM AUTHOR]

Ceramic membranes are increasingly recognized for their effectiveness in processing fermentation broths. However, developing ceramic membranes with superior anti-fouling properties remains a challenge for large-scale applications. Iron oxide nanomaterials have gained significant research interest as a cost-effective and readily available solution for mitigating membrane fouling, thanks to their excellent hydrophilicity. This study introduces ceramic membranes enhanced with iron oxide via a facile sol-gel technique. The membrane's resistance to fouling, hydrophilicity, adhesion force, and surface potential were assessed. Post-modification, a consistent distribution of iron elements on the membrane surface was achieved, with negligible alteration in pore size. Although the pure water permeance (450 ± 45 L m−2 h−1·bar−1) did not change significantly, the permeance of the modified membrane (225 L m−2 h−1·bar−1) was nearly 20 % higher than that of the original membrane when separating a 1000 ppm oil-in-water emulsion, with both membranes achieving 99 % oil droplet rejection. Moreover, the flux recovery rate of the modified membrane surpassed that of the original membrane by approximately 30 %, indicating a significant improvement in anti-fouling performance. Upscaling experiments further validated the modified membrane's anti-fouling performance and capability to rapidly process broths with high oil content. Overall, this study presents a novel anti-fouling ceramic membrane for the treatment of oil-containing fermentation systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metals in MSW IBA begin to be mobilised to aqueous solution at below neutral pH. • MSW IBA has a high pH buffering capacity. • Reaching below neutral pH with rainwater infiltration is extremely unlikely. • DOC causes enhanced metal mobilization only at unrealistically high concentrations. • Persistent organic pollutants in the MSW IBA are well below regulatory limits. Increasing municipal solid waste (MSW) production poses challenges for sustainable urban development. Modern energy-from-waste (EfW) facilities incinerate MSW, reducing mass and recovering energy. In the UK, MSW incineration bottom ash (MSW IBA) is primarily reused in civil engineering applications. This study characterizes UK-produced MSW IBA, examining its pH-dependent leaching behaviour and response to environmental lixiviants. Results show predominant components include a melt phase, primary glass and fine ash aggregations, and a chemical composition dominated by SiO 2 (30–50 %), CaO (∼15 %), Fe 2 O 3 (∼10 %), and Al 2 O 3 (∼8%). X-ray absorption near edge structure (XANES) analysis shows that Zn and Cu are most likely oxygen-bound (adsorbed to oxy-hydroxides and as oxides) with some sulphur bound. Polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins/furans (PCDD/Fs) are well below regulatory limits, and polycyclic aromatic hydrocarbons (PAHs) were undetectable. Leaching tests indicate trace elements mobilize at pHs ≤ 6. With a natural pH of 11.3 and high buffering capacity, significant acid inputs to the MSW IBA are required to reach this pH, which are improbable in the environment. Wood chip additions increase leachate's dissolved organic carbon (DOC) and reduce pH, but had minimal impact on metal-leaching behaviour. Synthetic plant exudate solutions minimally affect metal leaching at realistic concentrations, only enhancing leaching at ≥ 1500 mg l−1 DOC. This work supports MSW IBA's low-risk in specified civil engineering applications. [ABSTRACT FROM AUTHOR]

The use of thermite to aid spacecraft demise during atmospheric re-entry has been investigated in the ESA-TRP SPADEXO project. An experimental campaign in DLR's L2K arc-heated wind tunnel facility was dedicated to explore the Thermite-for-Demise concept. Steel mock-ups of a ball bearing unit, partially filled with thermite, were placed in L2K. The breadboards were then exposed to an air flux simulating the typical conditions that characterize spacecraft re-entry. In this paper, the key results of the tests are presented. The dispersion of a mechanically activated fraction of thermite proved to be effective in controlling the overall charge ignition temperature. Thermite-induced demise was experimentally verified in the wind tunnel. The SCARAB software was extended and used to rebuild the retrieved thermal data. The results of the simulations were in good agreement in both predicting the ignition timing and the effects of the thermite charge on the sample. • Thermite-induced demise was verified in hypersonic wind tunnel conditions. • Mechanical activation can tune thermite passive ignition in space-like environment. • Numerical models can describe and foresee thermite-induced demise. [ABSTRACT FROM AUTHOR]

The superior anti-oxidation layer induced by the PVA-boehmite sol-gel film on the AISI304 steel during the cyclic oxidation is investigated in this work. The moderate PVA addition in the boehmite sol conduces to increase the film thickness and is beneficial to the adhesion between the film and the substrate. The presence of the PVA-boehmite film leads to a significant reduction in mass gain during the high-temperature cyclic oxidation at 800 °C, demonstrating the enhanced oxidation resistance. The generated oxide layer induced by the PVA-boehmite film presents as a thin, compact, and continuous layer without spalling, offering sustainable protection against oxidation etching. The PVA-boehmite film promotes the preferential formation of the corundum (Al, Cr) 2 O 3 phase rather than the detrimental hematite Fe 2 O 3 phase during the oxidation procedure, which facilitates the development of the above compact oxide layer. Finally, the superior anti-oxidation oxide layer is characterized as a novel dual-layer structure: the outer spinel MnCr 2 O 4 layer and the inner corundum (Al, Cr) 2 O 3 layer, effectively delaying the oxidation process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Desulfurization in waste tire pyrolysis oil and gas was achieved by metal oxides. • Fe 2 O 3 shows the best removal efficiency of 87.7% for sulfur-containing gas. • The desulfurization mechanism was revealed by ReaxFF-MD and experiments analysis. • The removal of S involved Fe-S bonding, C-S breakage, dehydrogenation, O migration. • Fe 2 O 3 promotes cyclization and dehydrogenation to produce monoaromatics (57.4%). Pyrolysis can effectively convert waste tires into high-value products. However, the sulfur-containing compounds in pyrolysis oil and gas would significantly reduce the environmental and economic feasibility of this technology. Here, the desulfurization and upgrade of waste tire pyrolysis oil and gas were performed by adding different metal oxides (Fe 2 O 3 , CuO, and CaO). Results showed that Fe 2 O 3 exhibited the highest removal efficiency of 87.7 % for the sulfur-containing gas at 600 °C with an outstanding removal efficiency of 99.5 % for H 2 S. CuO and CaO were slightly inferior to Fe 2 O 3 , with desulfurization efficiencies of 75.9 % and 45.2 % in the gas when added at 5 %. Fe 2 O 3 also demonstrated a notable efficacy in eliminating benzothiophene, the most abundant sulfur compound in pyrolysis oil, with a removal efficiency of 78.1 %. Molecular dynamics simulations and experiments showed that the desulfurization mechanism of Fe 2 O 3 involved the bonding of Fe-S, the breakage of C-S, dehydrogenation and oxygen migration process, which promoted the conversion of Fe 2 O 3 to FeO, FeS and Fe 2 (SO 4) 3. Meanwhile, Fe 2 O 3 enhanced the cyclization and dehydrogenation reaction, facilitating the upgrade of oil and gas (monocyclic aromatics to 57.4 % and H 2 to 22.3 %). This study may be helpful for the clean and high-value conversion of waste tires. [ABSTRACT FROM AUTHOR]

Microorganisms can exist in both suspended and attached forms in natural and engineered systems. While extensive research has been performed to investigate the bioreduction kinetics of iron oxides by suspended microorganisms, the kinetics of iron oxide reduction by biofilms has not been well studied. This study investigated the rates of ferrihydrite bioreduction by biofilms of Shewanella oneidensis MR-1 with variable concentration ratios of electron donor to acceptor, and different biofilm thickness. Results indicated that the bioreduction rate of ferrihydrite by biofilms increased with increasing biofilm surface area and was faster than that by suspended microorganisms for the same biomass amount, apparently as a result of the biofilm surface area facilitating the direct contact between ferrihydrite and microorganisms for electron transfer. Increasing biofilm thickness decreased bioreduction rate for the same total biomass as a result of the decrease of the ratio of the biofilm surface area to total biomass. The bioreduction rate increased with increasing electron donor and ferrihydrite inputs, consistent with the saturation type of kinetic models. The different rates of ferrihydrite reduction in the biofilm system resulted in different rates of Fe(II) production as a function of electron donor, acceptor, and biofilm surface area, which in turn affected the type and concentrations of the secondary iron minerals, such as lepidocrocite and goethite. A kinetic model was developed that integrates biofilm surface area, and electron donor and acceptor concentrations that well described the measured rates of ferrihydrite bioreduction. The results emphasized the importance of the biofilm surface area in understanding and modeling iron redox biogeochemistry and iron-related biogeochemical processes. [ABSTRACT FROM AUTHOR]

Aluminum dross (AD) and red mud (RM) are waste discharged from aluminum industry. AD and RM contain 5-15 wt% of hazardous aluminum nitride (AlN) and 20–50 wt% of iron oxide, respectively. In this work, alumina-based cermet was in-situ prepared from AD and RM, after reduction of iron oxide with AlN by pyrometallurgy. Cermet was consisted of metal reinforcement phase about 1 μm, alumina matrix phase and low-melting aluminosilicate binder. Mechanism of in-situ preparation was studied after exploring phase composition of the cermet powder. Iron, silicon and titanium oxide from RM was reduced into Fe 3 Si and TiN, which acted metal reinforcement phase in cermet. Reaction was consisted of two steps, Fe 2 O 3 , TiO 2 and AlN dissolving into low-melting aluminosilicate and electron transferring from AlN to Fe 2 O 3 , SiO 2 and TiO 2. Content of Fe in ceramic phase was decreased from 6 at.% to 1 at.% after reduction reaction. Low-melting aluminosilicate acted both reaction solvent for reduction reaction, and binder for metal reinforcement phase and alumina matrix phase. More low-melting aluminosilicate was formed when temperature was increased from 1200 °C to 1400 °C, which made more metal balls be formed. The metal ball and alumina were bonded by low-melting aluminosilicate, which increased the bond strength between reinforcement phase and ceramic phase in cermet. This work achieved a total recycle of AD and RM into cermet. It was proposed a novel idea of in-situ preparing cermet, which was generating metal reinforcement phase in ceramic matrix phase. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the color effects of novel Fe 2 O 3 /flake α-Al 2 O 3 pearlescent pigments prepared with different Fe salts and colorant dosages were investigated. First, Fe 2 O 3 /flake α-Al 2 O 3 pearlescent pigments with hexagonal flakes were successfully prepared by liquid-phase deposition. Second, the color effects of these pearlescent pigments were systematically investigated by changing the Fe salt and its dosage. The surface morphology, elemental distribution, and phase structures of the pigments were comprehensively characterized by scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffractometry. The results show that the color intensity of the pigments is affected by the Fe salt and its dosage. In addition, pigments prepared from different Fe salts show different colors. The color of the pigments was found to gradually deepen with increasing colorant dosage, and the pearlescent pigments obtained showed rich color effects. Therefore, different colors can be obtained by varying the colorants and their dosage, and this in turn enables the controllable preparation of different colors. Finally, the possible formation mechanism of the color effects was considered. Due to the different hydrolysis ability of the different colorants, the amount of Fe(OH) 3 generated by hydrolysis is different for each; thus, different coating ratios are obtained, resulting in different color effects. The results of this study provide a strong reference for the preparation of high-end pearlescent pigments and the modulation of their colors. [ABSTRACT FROM AUTHOR]

The adsorption behaviors, reaction pathways and coupling mechanism of α-Fe 2 O 3 (0001) surface with the H 2 molecules and CO molecules in hydrogen-based shaft furnace were investigated at the atomic level based on the density functional theory. The results showed that the most stable adsorption configuration of H 2 molecule has an adsorption energy of −1.65 eV, whereas CO molecule is −2.10 eV. The most stable adsorption sites are both O atom, but the adsorption of CO molecule is more stable compared to H 2 molecule. The energy barrier of H 2 molecule is 0.64 eV and 0.76 eV of energy need to be absorbed after generating one free H 2 O molecule. While CO molecule reacts with an energy barrier of 1.40 eV and 0.09 eV of energy has to be released after generating one free CO 2 molecule. The reaction of H 2 molecules with Fe 2 O 3 is kinetically dominant but thermodynamically adverse. Increasing the temperature is detrimental to the adsorption of gas molecules but favors the reduction reaction, and can compensate for the thermodynamic disadvantage of adsorption and reaction for H 2 molecules. The adsorption energy per H 2 molecule is −1.51 eV and that of per CO molecule is −1.03 eV. The adsorption energy of −2.67 eV for the co-adsorption of one H 2 molecule and one CO molecule is less than the linear sum of adsorption energies when they adsorb separately, suggesting a synergistic mechanism for the interaction of H 2 and CO with Fe 2 O 3. This work can provide theoretical guidance for hydrogen-rich or even pure hydrogen reduction in hydrogen-based shaft furnace. • The adsorption of H 2 is unstable compared to CO and the most stable sites are O. • The reaction energy barrier of H 2 is lower than CO, which is kinetically dominant. • Increasing the temperature can compensate for the thermodynamic disadvantage of H 2. • A synergistic mechanism for the interaction of H 2 and CO with Fe 2 O 3. [ABSTRACT FROM AUTHOR]

In this work, passivation of X80 pipeline steel was established at various passive potentials in a carbonate/bicarbonate solution. The passive films were characterized by topographical, compositional, and structural analysis techniques and electrochemical measurements. The effect of the passive film on hydrogen (H) atom permeation was investigated by electrochemical H permeation testing and scanning Kelvin probe force microscopy. The passive films primarily comprise Fe 2 O 3 /Fe 3 O 4 and FeOOH. In the stable passive region, notably at 0.25 V (saturated calomel electrode, SCE), the formed passive film exhibits the highest film resistance, and the smallest double-layer capacitance and donor density. In contrast, oxide films formed at −0.1 V(SCE) and 0.55 V(SCE), which close to the active-passive transition and the transpassive regions, respectively, differ in their characteristics. The oxide films formed at −0.1 V(SCE) and 0.25 V(SCE) exhibit resistance against H atom permeation, and a superior performance is observed in the film formed at 0.25 V(SCE). The oxide film formed at 0.55 V(SCE) exhibits increased H atom permeation, which is attributed to the degraded structure of the film. Thus, the presence of compact oxide film (scale) on steel surface can effectively inhibit H atom permeation into the steel. • Prepared oxide films with various structures and morphologies on the surface of X80 pipeline steel. • Determined the role of oxide film in inhibition of hydrogen atom permeation into the steel. • Proposed an index to evaluate the inhibition performance of the oxide film in resistance to hydrogen permeation. [ABSTRACT FROM AUTHOR]

The transition to more environmentally friendly steel production methods has intensified research into hydrogen-based direct reduction (HyDR) of iron oxide pellets. The aim of this study is to systematically investigate the kinetics of the reduction process, the evolution of porosity and the resulting microstructural changes on the reduction behavior of high-quality pellets during HyDR of iron ore at different temperatures. A modified mathematical model is developed based on the shrinkage kernel model, taking into account both mass and heat transport in a hydrogen atmosphere. The effects of temperature, particle size and time on the reduction behavior of the pellets are investigated. The simulated results are validated and discussed by the results of a batch of iron oxide pellets consisting of ten almost spherical pellets subjected to the direct reduction process with pure hydrogen. The results show that the total energy input to the HyDR process is a complex balance of factors, including chemical reaction rates, diffusion dynamics and entropy generation. The increase in free volume and simultaneous decrease in pore diameter reflect the dynamic nature of the microstructure, which includes additional free volume and defects due to the volume discrepancies and associated stresses between the reactant and product phases. Furthermore, the data show that higher temperatures accelerate the reduction reactions, especially the transformation of wustite into metallic iron. This phase transition is characterized by a significant volume change that cannot be accommodated by elastic deformation alone, leading to the development of lattice defects such as cracks, creep pores and dislocations that serve as stress relief mechanisms. The trends for porosity change at 950 °C and 1000 °C observed in the experimental results are correct and in good agreement with the numerical and simulated results. [Display omitted] • Development of a model to evaluate HyDR kinetics and microstructural changes in iron oxide pellets. • Higher temperatures accelerate HyDR, which affects phase transitions and defect formation. • Temperature-induced porosity affects kinetics and gas diffusion despite tortuosity. • HyDR leads to stress defects and increased porosity in the microstructure. • The interaction of kinetics and entropy in the optimization of the HyDR process for steel was highlighted. [ABSTRACT FROM AUTHOR]