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Co3O4 has been considered a promising anode material because of its high theoretical capacity (890 mAh/g) and remarkable energy density. Unfortunately, it suffers from low initial coulombic efficiency, rapid capacity fading, poor electronic conductivity, large volume changes, and aggregation during the lithium ion intercalation/deintercalation process. In this work, a series of Fe2+-doped Co3O4 nanostructured materials Co3(1-x)Fe3xO4 (x = 0, 0.01, 0.02 and 0.03) were produced by a simple chemical co-precipitation method. The Fe doping led to a slight increase of the lattice parameter, which is beneficial to the rapid diffusion of Li+ ion during the lithiation/delithiation process. Meanwhile, the Fe-doped Co3O4 sample exhibited an excellent rate capability of 886.47 mAh/g at 500 mA/g, and outstanding cyclic stability (1156.91 mAh/g for 50 cycles, with the capacity retention rate of 83.53% at the current density of 100 mA/g), demonstrating improved electrochemical performance, compared with that of pure Co3O4. The good electrochemical performance profited from the formation of oxygen vacancies by Fe doping, which provided more space for Li+ diffusion and improved the electronic conductivity of the anode material. This work provides a simple way to improve the comprehensive electrochemical performance of the transitional metal oxide Co3O4 anode electrodes for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Undoped and Fe-doped NiO nanoparticles were successfully synthesized using a lyophilization method and systematically characterized through magnetization techniques over a wide temperature range, with varying intensity and frequency of the applied magnetic fields. The Ni1-xFexO nanoparticles can be described by a core-shell model, which reveals that Fe doping enhances exchange interactions in correlation with nanoparticle size reduction. The nanoparticles exhibit a superparamagnetic blocking transition, primarily attributed to their cores, at temperatures ranging from above room temperature to low temperatures, depending on the Fe-doping level and sample synthesis temperature. The nanoparticle shells also exhibit a transition at low temperatures, in this case to a cluster-glass-like state, caused by the dipolar magnetic interactions between the net magnetic moments of the clusters. Their freezing temperature shifts to higher temperatures as the Fe-doping level increases. The existence of an exchange bias interaction was observed, thus validating the core-shell model proposed.

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The removal of antibiotics from wastewater to prevent their environmental accumulation is significant for human health and ecosystems. Herein, iron (Fe)-atom-doped anatase TiO2 nanofibers (Fe-TNs) were manufactured for the photocatalytic Fenton-like decomposition of tylosin (TYL) under LED illumination. Compared with the pristine TiO2 nanofibers (TNs), the optimized Fe-TNs exhibited improved visible-light-driven photocatalytic Fenton-like activity with a TYL degradation efficiency of 98.5% within 4 h. The effective TYL degradation could be attributed to the expanded optical light absorption and accelerated separation and migration of photogenerated electrons and holes after the introduction of Fe. The photogenerated electrons were highly conducive to the generation of active SO4•− radicals as they facilitated Fe(III)/Fe(II) cycles, and to oxidizing TYL. Moreover, the holes could be involved in TYL degradation. Thus, a significant enhancement in TYL degradation could be achieved. This research verifies the use of iron-doped anatase nanofibers as an effective method to synthesize novel photocatalytic Fenton-like catalysts through surface engineering for wastewater remediation. [ABSTRACT FROM AUTHOR]

We performed first-principles calculations to investigate the effect of Cu or Fe partial substitution in MnCoGe on the stabilization of the hexagonal structure. In the case of Cu partial substitution at x = 0.125, a substitution for one site is more effective than that for both sites. In the case of Fe partial substitution at x = 0.125, there is no difference between two types of substitution for both sites and the Mn site. The result of Fe partial substitution at x = 0.25 indicates that Fe partial substitution for both sites is more effective than that for the Mn or the Co site. [ABSTRACT FROM AUTHOR]

In this work, a series of pure and doped SnO2 nanoparticles (SF0, SF5, and SF10 NPs) are successfully synthesized by the sol-gel method. The structural, optical, functional, morphological, and magnetic behaviors were distinguished by the XRD, UV, PL, FTIR, SEM with EDAX and HR-TEM techniques respectively. From the XRD analysis, the tetragonal SnO2 nanostructures were identified with an observed crystallite size from 7.4 to 15.2 nm. The UV-visible absorption spectra of SF0, SF5, and SF10 nanoparticles were observed around 331, 339, and 343 nm and their energy gap values were calculated to be 3.74, 3.65, and 3.61 eV. The PL emission peaks that appeared at 366 and 485 nm were attributed to the free of charge exciton electron-hole recombination and the surface defects of O2 vacancy in these SnO2 nanoparticles, respectively. The vibration properties of SF0, SF5 and SF10 nanoparticles were recognized using FTIR spectra. The strong Sn = O vibration modes observed at 1083 cm−1 was characterized to the external surface cation- oxygen (Sn and O) bonds. SEM images revealed that the indefinite and spongy cluster for both SF0 and SF5 and the agglomerated spherical-like morphologies of SF10 EDAX analyses confirmed the Sn, O, and Fe contents in all doped samples. The HR-TEM image of the SnO2 NPs contains with a d-spacing which corresponds to the interplaner distance of planes of SnO2. The photocatalytic performance of SF0, SF5, and SF10 nanoparticles were tested through the degradation of methylene blue (MB) dye in UV light irradiation, and the results reveal 85% degradation effectiveness of MB by SF10 over a period of 180 min. [ABSTRACT FROM AUTHOR]

Exploring high-performance and multifunctional electrocatalysts for alcohols oxidation is the key to develop alkaline fuel cells. Herein, we prepared a novel palladium-nickel-phosphorus catalyst supported on single atom iron carbons (SAICs) with different diameter sizes (1000 nm, 200 nm, 100 nm, 50 nm, and 20 nm), which were synthesized by direct carbonization of Fe-doped Zeolitic Imidazolate Framework-8 (ZIF-8). Electrochemical tests reveal that the as-prepared PdNiP/50nmSAIC exhibited excellent electrooxidation activity and stability to the various alcohols (methanol, glycerol, and especially ethylene glycol) electrooxidation in the alkaline solution, which is much higher than that of commercial Pd/C and other advanced Pd-based catalysts. Meanwhile, the rotating disk electrode (RDE) and CO-stripping results proves that PdNiP/50nmSAIC possesses a faster kinetic process of ethylene glycol oxidation and enhanced anti-CO poisoning ability. Our efforts provide a new strategy for the development of MOFs-derived multielement electrocatalyst with excellent activity and stability, and a bright future for alcohol oxidation. Single atom iron carbons supported Pd–Ni–P nanoalloy as a multifunctional catalyst in the field of alkaline fuel cells. [Display omitted] • Single atom iron carbons (SAICs) with different particle sizes have been prepared as support. • PdNiP nanoparticles are highly dispersed on SAICs support. • PdNiP/50nmSAIC shows excellent activity and stability for methanol, glycerol and especially ethylene glycol oxidation. • PdNiP/50nmSAIC shows better CO poisoning tolerance and much faster kinetics of ethylene glycol oxidation. [ABSTRACT FROM AUTHOR]

High nitrogen content in fiberboard is a common industrial waste that, if left untreated, can lead to environmental pollution and resource wastage. This study aims to produce nitrogen-rich fiberboard char (FC) from waste fiberboard through CO 2 activation and Fe-doping, and to investigate its effectiveness in removing methylene blue (MB) from solution. The elemental composition, pore structure, micromorphology, and functional group distribution of FC were analyzed using ultimate analysis, BET, XRD, FTIR, SEM, and XPS. Additionally, the study delved into isothermal adsorption, adsorption kinetics, and potential adsorption mechanisms. The char (FC-CO 2 -Fe), prepared through the synergistic activation of CO 2 and Fe-doping, exhibited a larger specific surface area, a developed micropore structure, and abundant nitrogen and oxygen functional groups on its surface, making it more effective for the adsorption of MB. The π-π interaction between the ring structure of FC and the aromatic ring structure of MB, along with the electrostatic interaction between the functional groups, further enhanced its adsorption properties. Experimental findings indicated that FC achieved a maximum adsorption capacity of 56.61 mg/g for MB, with a removal efficiency of 37.74 %. Both Langmuir and Freundlich isothermal adsorption models, as well as pseudo-first-order and pseudo-second-order kinetic models, successfully described the isothermal adsorption and adsorption kinetics of MB by FC. The adsorption process appeared to involve a combination of physical and chemical adsorption mechanisms. Therefore, FC shows promise as a potential adsorbent for treating dye wastewater, with favorable prospects for applications. [Display omitted] • Fe-doped N-rich FC enhanced adsorptive removal of MB. • Maximal adsorption and removal efficiency of FC-CO 2 -Fe for MB reached 56.61 mg/g and 37.74 %. • Physical adsorption, functional groups, π-π and electrostatic interactions were the main driving forces of adsorption. [ABSTRACT FROM AUTHOR]

The removal of antibiotics from wastewater to prevent their environmental accumulation is significant for human health and ecosystems. Herein, iron (Fe)-atom-doped anatase TiO2 nanofibers (Fe-TNs) were manufactured for the photocatalytic Fenton-like decomposition of tylosin (TYL) under LED illumination. Compared with the pristine TiO2 nanofibers (TNs), the optimized Fe-TNs exhibited improved visible-light-driven photocatalytic Fenton-like activity with a TYL degradation efficiency of 98.5% within 4 h. The effective TYL degradation could be attributed to the expanded optical light absorption and accelerated separation and migration of photogenerated electrons and holes after the introduction of Fe. The photogenerated electrons were highly conducive to the generation of active SO4•− radicals as they facilitated Fe(III)/Fe(II) cycles, and to oxidizing TYL. Moreover, the holes could be involved in TYL degradation. Thus, a significant enhancement in TYL degradation could be achieved. This research verifies the use of iron-doped anatase nanofibers as an effective method to synthesize novel photocatalytic Fenton-like catalysts through surface engineering for wastewater remediation.

Nickel-based catalysts are suitable for water splitting to generate hydrogen. However, the low conductivity and weak stability have always been urgent issues to be addressed in nickel-based catalysts. Fe-doped nickel oxide/nickel phosphide (Fe-NiO/Ni 2 P) was prepared as a bifunctional electrocatalyst by doping metal and constructing heterogeneous interface. The introduction of Fe contributed to the reinforced interfacial coupling effect of NiO/Ni 2 P to promote charge transfer and accelerate reaction kinetics. The heterojunction regulated the interfacial charge density between NiO and Ni 2 P to improve the electronic environment of Ni 2+ and enhance conductivity. The O-Fe-P bond at the heterogeneous interface induced the directional transfer of electrons and ensured the structure stability. The synergistic effect of Fe doping and heterogeneous interface increased the adsorption energy of *O and coordinated the adsorption energy of *H, advancing the catalytic performance. Fe-NiO/Ni 2 P exhibited the overpotential of 242 mV and 141 mV at 10 mA cm -2 for oxygen and hydrogen evolution, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In recent years, catalysts based on transition metal sulfides have garnered extensive attention due to their low cost and excellent electrocatalytic activity in the alkaline oxygen evolution reaction. Here, the preparation of Fe-doped Ni 3 S 2 via a one-step hydrothermal approach is reported by utilizing inexpensive transition metals Ni and Fe. In an alkaline medium, Fe-Ni 3 S 2 exhibits outstanding electrocatalytic activity and stability for the OER, and the current density can reach 10 mA cm -2 with an overpotential of 163 mV. In addition, Pt/C||Fe-Ni 3 S 2 is used as the membrane electrode of the anion exchange membrane water electrolyzer, which is capable of providing a current density of 650 mA cm -2 at a cell voltage of 2.0 V, outperforming the benchmark Ir/C. The principle is revealed that the doping of Fe enhances the electrocatalytic water decomposition ability of Ni 3 S 2 by in situ Raman and in situ X-ray absorption fine structure. The results indicate that the doping of Fe decreases the charge density near Ni atoms, which renders Fe-Ni 3 S 2 more favorable for the adsorption of OH - and the formation of * OO - intermediates. This work puts forward an effective strategy to significantly improve both the alkaline OER activity and stability of low-cost electrocatalysts., (© 2024 Wiley‐VCH GmbH.)

The Li+ adsorption from aqueous solution by lithium-ion sieve has become one of the most promising methods due to the high efficiency and selectivity towards lithium ion (Li+). However, the industrial application of manganese oxide ion-sieve is limited due to its difficult separation and decrease of adsorption capacity resulting from manganese dissolution loss. In this paper, the magnetically recyclable Fe-doped manganese oxide lithium ion-sieves with spinel-structure were proposed and prepared from LiMn2-xFexO4 synthesized by solid state reaction method. The effects of calcination temperature, calcination time and Fe doping amounts on the phase compositions, dissolution loss and adsorption performance of lithium ion-sieve precursors were systematically studied, and the influences of solution pH value, initial Li+ concentration and adsorption temperature on the adsorption performance were investigated. The adsorption mechanism was further discovered through adsorption kinetics and thermodynamics. The results show that the adsorption capacity of lithium ion-sieves could reach to 34.8 mg·g–1 when the calcination temperature, time and Fe doping content were controlled at 450 °C, 6 h, and 0.05, respectively. The Mn dissolution loss was reduced to 0.51%, much lower than the undoped lithium ion-sieve (2.48%), which is attributed to the inhibition of disproportionation reaction with the increasing proportion of Mn4+ in the skeleton. The adsorption process conformed to the pseudo-second-order kinetics equation and Langmuir isothermal adsorption model. Furthermore, the recycling performance of Fe-doped lithium ion-sieve showed that the adsorption capacity could remain 22.5 mg·g–1 (about 70%) after five cycles, which is greater than that of undoped lithium ion-sieve (about 50%), and the recovery of lithium ion-sieve can be realized by magnetic separation in an applying magnetic field.

Metal organic frameworks (MOFs) have been used widely as cathode materials for supercapacitors because of their adjustable chemical composition, variable topological structures, and relatively simple synthesis methods. However, most MOFs are insulated and their metal organic ligand coordination bonds are not stable enough in electrolytes, which greatly limits the application of MOFs in supercapacitors. The synergistic effect between transition metal doped and chemical etching is of great significance for the preparation of high-performance MOF electrodes. This study introduces Fe into Co MOF prepared by co precipitation to optimize the electronic structure of Co, and then constructed e-Fe-doped Co MOF hierarchical structure through ammonia etching. The Co MOF achieves rapid electron exchange at the electrode electrolyte interface through this synergistic effect, improving conductivity, and increasing specific surface area, exposing more active sites, effectively enhancing the electrochemical activity of the electrode. Therefore, the e-Fe-doped Co MOF-4 h has a high specific capacity of 700 C g−1 at 1 A g−1 with a 90.08 % high-rate performance. The assembled e-Fe-doped Co MOF-4 h//N-doped WC ASC provides the energy density of 80 Wh kg−1 at a power density of 800 W kg−1 with a ∼88 % capacitance retention after 10000 cycles. These results provide ideas for utilizing synergistic effects to prepare high-energy density supercapacitors using MOF materials. • The e-Fe-doped Co MOF-4 h has a 2D nanosheet structure with rough surface. • Fe-doped regulates the d -orbital electronic configuration of Co. • Due to the synergistic effect, e-Fe-doped Co-MOF-4 h has the highest specific capacity. • The e-Fe-doped Co MOF-4 h//N-doped WC ASC delivers a high energy density. [ABSTRACT FROM AUTHOR]

Aiming at the problem of poor arc ablation resistance of Ag-SnO2 electrical contact materials, Fe-doped SnO2 powders with different contents were prepared by sol-gel method, Fe-doped Ag/SnO2 electrical contact material were prepared by high-energy ball milling process. XRD, UV-Vis, BET and SEM were used to analyze the prepared materials. The results are as follows: with the increase of Fe content, the hardness, density and electrical conductivity of the Ag/SnO2 contact material first increase and then decrease. When the Fe/Sn molar ratio is 12%, the hardness, electrical conductivity and density of the Fe-doped Ag/SnO2 contact material are the highest, and the hardness, conductivity and density increase by 5.99%、6.73% and 0.32% respectively. Fe-doped improves the adsorption ability of SnO2 particles to heterogeneous molecules, the interface bonding force between Ag and SnO2 particles, and the interfacial wettability between Ag and SnO2, thereby improving the arc erosion resistance of the Ag/SnO2 contact material.

Improving the insufficient carrier separation dynamics is still of significance in carbon nitride (C3N4) research. Extensive research has been devoted to improving the carrier separation efficiency through a single strategy, while ignoring the synergistic enhancement effect produced by coupling two or more conventional strategies. Herein, we reported the fabrication of cyano group‐containing Fe‐doped C3N4 porous materials via direct co‐calcination of iron acetylacetonate and melamine for synergistically improving the photocatalytic performance. Iron acetylacetonate can promote the generation of cyano groups and form Fe‐doping in C3N4, thereby increasing the visible‐light absorption and reactive sites. Further, the internal donor‐acceptor system formed by cyano groups and Fe‐doped sites promoted charge carrier separation and inhibited the radiation recombination of e−‐h+ pairs. The optimized photocatalytic activity of Fe−CN‐2 sample was 4.5 times of bulk C3N4 (BCN). [ABSTRACT FROM AUTHOR]

Improving the insufficient carrier separation dynamics is still of significance in carbon nitride (C3N4) research. Extensive research has been devoted to improving the carrier separation efficiency through a single strategy, while ignoring the synergistic enhancement effect produced by coupling two or more conventional strategies. Herein, we reported the fabrication of cyano group‐containing Fe‐doped C3N4 porous materials via direct co‐calcination of iron acetylacetonate and melamine for synergistically improving the photocatalytic performance. Iron acetylacetonate can promote the generation of cyano groups and form Fe‐doping in C3N4, thereby increasing the visible‐light absorption and reactive sites. Further, the internal donor‐acceptor system formed by cyano groups and Fe‐doped sites promoted charge carrier separation and inhibited the radiation recombination of e−‐h+ pairs. The optimized photocatalytic activity of Fe−CN‐2 sample was 4.5 times of bulk C3N4 (BCN). [ABSTRACT FROM AUTHOR]

Ab initio study of high-pressure phase transition and electronic structure of Fe-doped CeO2 with Fe concentrations of 3.125, 6.25, and 12.5 at% has been reported. At a constant-pressure consideration, the lattice constants and the volume of the supercell were decreased with an increasing concentration of Fe. The average bond length of Fe–O is lower than that of Ce–O. As a result, Fe doping induces the reduced volume of the cell, which is in good agreement with previous experiments. At high pressure (~ 30 GPa), it was found that the transition pressure from the fluorite to the cotunnite orthorhombic phase decreases at a higher concentration of Fe, indicating that the formation energy of the compound is induced by Fe-doping. Furthermore, compression leads to interesting electronic properties too. Under higher pressures, the bandgap increases in the cubic structure under compression and then suddenly plummets after the transition to the orthorhombic phase. The 3d states of Fe mainly induced the impurity states in the bandgap. In both the undoped and Fe-doped systems, the bandgap increased in the cubic phase at high pressure, while the gap and p-d hybridization decrease in the orthorhombic phase. [ABSTRACT FROM AUTHOR]

In this work, a green Fe-doped TiO 2 photocatalyst was successfully synthesized on Ti mesh through the chemical impregnation and anodization method. The influence of sample Fe-content on the photocatalytic performance was investigated in detail. Ordered TiO 2 nanomesh was compactly decorated with nanospheres to form a novel photocatalyst Fe-doped TiO 2 with anatase phase. Simultaneously, it exhibits higher light absorption intensity compared to the pristine TiO 2 within the visible light range, and its absorption peak has a redshift. The VSM results showed that the sample has excellent magnetic properties. It is hard to achieve magnetic agglomeration after magnetic field removal, which benefits the strong recyclability and reusability of Fe-doped TiO 2 photocatalyst. Importantly, this higher visible-light photoresponse of TiO 2 was clearly obtained after Fe doping. When the Fe-content was 0.6 wt%, the degradation rate of methylene blue reached 87.9% under simulated sunlight irradiation for 2.5 h. The prepared nanocrystalline photocatalyst demonstrated excellent photocatalysis because of its prominent crystal morphology, strengthen light-absorption capacity, and commendable inhibition recombination of photo-induced electron-hole. [ABSTRACT FROM AUTHOR]

• (Ni, Fe)-ZIF-67 was synthesized by a simple chemical reaction. • The bigger ionic radius of Fe-ZIF causes to have more polarization than Ni-ZIF. • All samples showed the NLR and self-defocusing effect in the order of 10−8 cm2/W. • The NLA coefficient (∼10−5 cm/W) of samples are due to two-photon absorption effect. • The crystallinity index of (Ni, Fe)-ZIF-67 were increased in comparison with ZIF-67. A simple chemical reaction was applied for fast preparation of pure zeolitic imidazolate framework-67 (ZIF-67) and doped with Ni or Fe ions. The distinctive bands appeared in FT-IR spectrum of each samples confirmed the successful synthesis of ZIF-67 samples. The surface morphology and microstructure of prepared pure ZIF-67 were evaluated by TEM and SEM techniques. A rhombic dodecahedron skeleton with smooth surface was shown for the ZIF-67. The SEM images of ZIF-67 doped with Ni or Fe indicated a polyhedral shaped nanostructures smaller than 300 nm. Considering the XRD pattern, the crystallinity index of samples was calculated. The large optical nonlinearities of Ni, and Fe doping ZIF-67 were characterized using a 532 nm wavelength laser source. All synthesized samples showed the nonlinear refractive index and the nonlinear absorption coefficient in the order of 10−8 cm2/W and 10−5 cm/W, respectively. The crystallinity index and polarizability of (Ni, Fe)-ZIF-67 were increased in comparison with ZIF-67. The bigger ionic radius causes to have more electrons and raises polarization. The large two-photon absorption (TPA) and self-defocusing effect of Fe-ZIF-67 made it suitable for related applications in optical limiting devices. [Display omitted] [ABSTRACT FROM AUTHOR]

• The iron doping facilitates the transfer of Na+ and alleviates structural deterioration. • A three-dimensional carbon framework, constructed from N-CNTs and carbon layer, enhances electron transport. • These approaches optimize the electrochemical performance of electrode material. Na 3 V 2 (PO 4) 2 F 3 (NVPF) has consistently stood out as one of the most popular cathode materials for sodium ion batteries (SIBs) because of its impressive theoretical specific capacity, high energy density and controllable structure. However, its application has been hindered by two major challenges: its low electron conductivity and poor diffusion kinetics caused by large Na+ radius. In this study, iron-doped Na 3 V 2- x Fe x (PO 4) 2 F 3 was prepared by hydrothermal solvothermal method to solve those issues. The iron doping facilitates the transfer of Na+ and alleviates structural deterioration. Simultaneously, the establishment of a three-dimensional carbon framework, constructed from N-CNTs and carbon layer, further enhances electron transport. Therefore, Fe 0.1 -NVPF@N-CNTs exhibited the initial discharge capacity reaching 105 mAh g−1 at 0.1 C , maintaining approximately 74.53% of its capacity after 1000 cycles at 2C, and a noteworthy capacity retention rate of 83.38% after 1200 cycles at 5C. The incorporation of Fe-doped NVPF coated with carbon layer and N-CNTs holds great promise in advancing the electrochemical performance of SIBs. [ABSTRACT FROM AUTHOR]

Aiming at the problem of poor arc ablation resistance of Ag-SnO2 electrical contact materials, Fe-doped SnO2 powders with different contents were prepared by sol-gel method, Fe-doped Ag/SnO2 electrical contact material were prepared by high-energy ball milling process. XRD, UV-Vis, BET and SEM were used to analyze the prepared materials. The results are as follows: with the increase of Fe content, the hardness, density and electrical conductivity of the Ag/SnO2 contact material first increase and then decrease, When the Fe/Sn molar ratio is 12%. the hardness, electrical conductivity and density of the Fe-doped Ag/SnO2 contact material are the highest. and the hardness, conductivity and density increase by 5.99%. 6.73% and 0.32% respectively. Fe doped improves the adsorption ability of SnO2 particles to heterogeneous molecules, the interface bonding force between Ag and SnO2 particles, and the interfacial wettability between Ag and SnO2 thereby improving the arc erosion resistance of the Ag/ SnO2 contact material. [ABSTRACT FROM AUTHOR]

Fe-doped V6O13 was synthesized via a facile hydrothermal method after preparing precursor in order to improve the discharge capacity and cycle performance of V6O13 cathode material at high-lithium state. XRD, SEM and XPS were employed to characterize the phase, morphology and valence of the Fe-doped V6O13. Meanwhile, the electrochemical performance was analyzed and researched. Different morphologies and electrochemical performances of Fe-doped V6O13 were obtained via doping different contents of Fe3+ ion. The sample 0.02 presented the largest thickness of nanosheets (the thickness of 600-900nm) and clearance between layers. The Fe-doped V6O13 has a better electrochemical performance than that of pure V6O13. The sample 0.02 exhibits the best electrochemical performance, the initial discharge specific capacity is 433mAh·g-1 and the capacity retention is 47.1% after 100 cycles.

Fe-doped mesoporous alumina (MA) was successfully synthesized via a facile one-pot synthesis method. The resulting Fe-doped MA samples possess typical mesoporous structure, relatively high BET surface area, and narrowed pore size diameter. Besides, the iron species are well-dispersed in the alumina matrix, and more importantly, some small oligonuclear iron oxide clusters are linked on the surface of alumina, leading to the elimination of strong acid sites. The reaction of phenol hydroxylation was preceded at room temperature for 2 h. The introduction of mesoporous structure in alumina would be favorable for the adsorption and diffusion process of reactant and product molecules, and also the well-dispersed iron species in alumina matrix and large amount of acid sites stimulate more active hydroxyl radicals which are greatly beneficial for the catalytic process, especially the elimination of strong acid sites would inhibit the over-oxidation reaction. In this case, the sample of 5Fe–MA displays the best catalytic performance especially with the extremely high dihydroxybenzene selectivity of 93.2%, and the good catalytic stability is also evidenced by the five times recycling tests. In this work, the Fe-doped mesoporous alumina (MA) was successfully prepared. The iron species are well-dispersed in the alumina matrix, and some small oligonuclear iron oxide clusters are linked on the surface of alumina, leading to the elimination of strong acid sites. The advanced properties of mesoporous structure, well-dispersed metal active centers and lack of strong acid sites in Fe-doped MA are greatly beneficial for the catalytic process, especially for the dihydroxybenzene selectivity with extremely high value of 93.2%. [ABSTRACT FROM AUTHOR]

Nonoxide ceramics microspheres with multiple compositions are attractive for wide applications especially in thermal insulation science. The flower-like Fe-doped Si–C–N ceramic microspheres with the average size of about 1 μm were fabricated from polyvinylsilazane and ferrocene precursor through polymer-derived ceramics technology combined with emulsion polymerization method. The properties of the resultant microspheres were characterized by FTIR, SEM-EDX, VSM, TGA, and XRD. The morphology and size of the microspheres could be tuned by changing of ferrocene content, cross-linking time, and pyrolysis temperature. The ceramic microspheres were estimated to be composed of SiC/Si3N4 and α-Fe/Fe2O3 crystal phase, and the folding sheets on the surface induced the flower-like morphology due to phase separation and crystal rearrangement. The effective extinction coefficient of silica aerogels opacified with 10 wt% of Fe-doped Si–C–N microspheres increased with rising pyrolysis temperature, the maximum value of e* reached 27.5 cm2/g at 1300 °C. Moreover, the microspheres showed weak room temperatures ferromagnetism, which was facilitated to alignment in fabrication and recycle, make them an ideal candidate for aerogels in infrared shielding application. Highlights: Novel Fe-doped Si-C-N ceramic microspheres with flower-like morphology were prepared by polymer-derived ceramics technology combined with the emulsion polymerization method. The morphology and size of microspheres could be tuned by changing conditions. Microspheres were composed of multiple crystals. Microspheres showed weak room temperature ferromagnetism. [ABSTRACT FROM AUTHOR]

A pure monolayer of orthorhombic MoO 3 and Fe-doped MoO 3 were constructed to study their hydrogen sensing properties through first-principle density functional theory (DFT) calculations. The results show that Fe can be stably doped into the MoO 3 monolayer with a high binding energy of −8.09 eV. Further calculations revealed that pure MoO 3 is insensitive to molecular oxygen or hydrogen. However, oxygen can be chemisorbed onto the doped Fe in the modified MoO 3 with a high adsorption energy of −0.807 eV, capturing approximately 0.2 e from the sensing material. The introduced hydrogen molecules tended to interact strongly with the pre-adsorbed O 2 molecule to form two H 2 O, releasing 1.01 e back to the sensing material. There were 1.92 e released back to the MoO 3 doped with two Fe atoms during the sensing process which significantly enhancing the hydrogen sensing performance of the modified material. Our study indicates that doping MoO 3 with Fe atoms improved its hydrogen sensing performance and is a reasonable way to design effective gas sensing materials. Image 1 • Pure MoO 3 monolayer (P–MoO 3) shows poor sensitivities to the O 2 or H 2 molecules. • There is 0.2 e captured when O 2 is adsorbed on MoO 3 doped with one Fe atom (Fe–MoO 3). • 1.01 e is released when Fe–MoO 3 with pre-adsorbed oxygen ions interacts with H 2. • The H 2 sensing property of MoO 3 can be further improved via doped with two Fe atoms. • Fe-doped MoO 3 was potential to show excellent hydrogen sensing property. [ABSTRACT FROM AUTHOR]

Olivine-type LiMnPO 4 (LMP) cathodes have gained enormous attraction for Li-ion batteries (LIBs) due to high discharge platform, theoretical capacity and thermal stability. However, it is still challenging to achieve encouraging Li-storage behavior owing to the low electronic conductivity and slow Li-ion diffusion rate of LMP. Here, the electrochemical behavior of fibrous LiFe x Mn 1-x PO 4 @carbon (LF x M 1-x P@C, x = 0, 0.25, 0.5, 0.75, 1) composites with different Fe doping amounts is investigated. Among the composites, LF 0.5 M 0.5 P@C demonstrates a superior cell performance due to a higher Li-ion diffusion coefficient (D Li), resulting from a proper Fe doping ratio and a more uniform morphology. At a current rate of 0.2 C (1 C = 170 mA g−1), the LF 0.5 M 0.5 P@C cathode delivers a specific capacity of 150 mAh g−1 up to 500 cycles with a capacity retention of 119%. A longer-term cycling at 5 C for 2000 cycles can be maintained with a reversible capacity exceeding 102 mAh g−1. The fundamental study provides an insightful guidance for future design of cathode materials with high performance. Image 1 [ABSTRACT FROM AUTHOR]

We have grown Fe-doped Co 3 S 4 nanosheets (Fe-Co 3 S 4 /NF) in situ on nickel foam using a hydrothermal method. Compared with the Co 3 S 4 powder catalyst, Fe doping changed the electronic structure of Co 3 S 4 , resulting in better OER performance, while the absence of binder made the material more stable, and the nanosheet structure greatly increased the effective area for electrochemical reactions. The catalyst has a Tafel slope of only 50.5 mV dec−1, which is superior to the current commercial RuO 2 catalyst. The material is inexpensive and simple to process, and has good stability in alkaline environments. [Display omitted] • OER performance of Fe-Co 3 S 4 /NF is better than commercial RuO 2. • The Fe-Co 3 S 4 /NF system shows good stability under alkaline conditions. • The Fe-doped Co 3 S 4 nanosheet arrays have a large specific surface area. • Iron doping activates new active sites and increases the OER performance. Oxygen evolution reaction (OER) is a complex four-electron coupled process, which significantly impacts the efficiency of the electrocatalytic reaction. Design and preparation of cost-effective and binder-free OER electrocatalysts are essential to improving catalytic efficiency. In this paper, Fe-doped Co 3 S 4 nanosheets have been directly deposited on nickel foam (NF) and applied to OER. Due to the synergy arising from the augmentation of active sites and charge transfer efficiency, Fe-Co 3 S 4 /NF exhibits excellent OER electrocatalytic activity. The overpotential of 242 mV and a Tafel slope of 50.5 mV dec−1 at a current density of 10 mA cm−2 was achieved in 1.0 M KOH solution, which was lower than commercial RuO 2. Fe-Co 3 S 4 /NF electrode also exhibits long-term stability, maintaining a consistent current density over a 20-hour testing period. This makes Fe-Co 3 S 4 /NF electrode has potential utilization in industrial applications. [ABSTRACT FROM AUTHOR]

In the last ten years, stannates with perovskite structure have been tested as photocatalysts. In spite of the ability of perovskite materials to accommodate different cations in its structure, evaluation of doped stannates is not a common task in the photocatalysis area. In this work, Fe3+ doped BaSnO3 was synthesized by the modified Pechini method, with calcination between 300 and 800ºC/4 h. The powder precursor was characterized by thermogravimetry after partial elimination of carbon. Characterization after the second calcination step was done by X-ray diffraction, Raman spectroscopy and UV-visible spectroscopy. Materials were tested in the photocatalytic discoloration of the Remazol Golden Yellow azo dye under UVC irradiation. Higher photocatalytic efficiency was observed under acid media. As no meaningful adsorption was observed at this condition we believe that an indirect mechanism prevails. Fe3+ doping decreased the band gap and favored the photocatalytic reaction, which may be assigned to the formation of intermediate levels inside the band gap.

• (In 1−x Fe x) 2 O 3 nanoparticles prepared by freeze-drying followed by heat treatment. • Freeze-drying is an effective technique for low temperature synthesis of semiconductors oxides free from impurity phases. • Fe-doped In 2 O 3 nanoparticles are bixbyite structure and single phase until the x = 0.12. • Iron concentration in the In 2 O 3 semiconductor reduced the lattice parameter, crystallite size, and optical bandgap. (In 1−x Fe x) 2 O 3 nanoparticles were prepared by freeze-drying an aqueous solution of indium acetate and iron acetate followed by heat treatment. The samples were characterized by high-resolution X-ray diffraction, transmission electron microscopy, Fourier transform infrared and UV–Vis diffuse reflectance spectroscopy. The x ≤ 0.12 nanoparticles were shown to be monophasic and crystallized with the bixbyite structure. Iron doping the In 2 O 3 semiconductor reduced the lattice parameter, crystallite size, and optical bandgap. [ABSTRACT FROM AUTHOR]

As an effective method to reduce the antibiotic contamination in water, photocatalysis has been widely investigated. Here, we report a preparation and tetracycline photodegradation of FeO x /Fe-Bi 2 O 2 CO 3 system. The system consists of FeO x nanoparticles deposited on Fe-doped Bi 2 O 2 CO 3. We used a simple one-step hydrothermal technique to successfully dope Fe into the Bi 2 O 2 CO 3 lattice and simultaneously deposit FeOx. Based on experiments and calculations, it is found that incorporation of Fe in Bi 2 O 2 CO 3 lattice results in a preferential growth of {001} facets, which are the active facets for photocatalytic reactions, and an increased light absorption in visible region. Additionally, FeO x nanoparticles increase light absorption and carriers' generation via an interfacial charge transfer. Moreover, FeO x acts as cocatalyst to trap photogenerated electrons and holes, reducing the carriers' recombination. A combination of positive effects from both Fe doping and FeO x deposition increase tetracycline photodegradation performance by two to three times compared to the pristine Bi 2 O 2 CO 3. Thus, this work provides an easy-to-prepare and enhanced Bi 2 O 2 CO 3 – based photocatalysts, which could benefit the future development of other materials in the field. • FeO x /Fe-Bi 2 O 2 CO 3 is prepared by a one-step hydrothermal method. • Fe doping in Bi 2 O 2 CO 3 causes {001} preferred orientation and increases light absorption. • Computations reveal that Fe in the lattice reduce (002) surface energy. • FeO x nanoparticles reduce carrier recombination and increase carrier generation. • FeO x /Fe-Bi 2 O 2 CO 3 show improved tetracycline degradation. [ABSTRACT FROM AUTHOR]

The problem of water pollution caused by antibiotic contamination is essential for human health and the ecological environment. In this study, Fe-doped TiO 2 (FT-2) photocatalyst with a hollow microsphere structure was fabricated for efficient photocatalytic-Fenton removal of tetracycline (TC) under visible light irradiation. The unique hollow microsphere structure of FT-2, iron doping and oxygen vacancies enhance the photo-Fenton activity and stability of the material. The results showed that the degradation rate of tetracycline in the FT-2 photo-Fenton system at 60 min was 98.18%, with a degradation efficiency of mostly 90% after five successful reuses. The efficient TC degradation activity should be mainly ascribed to the structure of hollow microspheres and oxygen vacancies, resulting in the extended optical light absorption in the visible light region, reduced compound efficiency of electron cavitation pairs, and accelerated separation and migration of photogenerated carriers. In addition, this highly benefits the formation of reactive radicals·O 2 - and h+ play a key role in the TC degradation in a photo-Fenton reaction system and thus lead to great improvement in TC removal according to the capture experiments and EPR. This study provides an idea for the construction of semiconductor catalysts with oxygen vacancy and doped with transition metal elements for the effective photocatalytic remediation of wastewater containing antibiotic contaminants. [Display omitted] • A novel FT-2/H 2 O 2 photo-Fenton system was developed. • ·O 2 - and h+ are the main reactive species in FT-2/H 2 O 2 photo-Fenton system under visible light condition. • The unique hollow microsphere structure of FT-2, iron doping and oxygen vacancies enhance the photo-Fenton activity. • The catalyst shows good recyclability and stability in application process. [ABSTRACT FROM AUTHOR]

• The Fe-doped Bi 12 O 17 Cl 2 nanotube is synthesized successfully. • The Fe-doped Bi 12 O 17 Cl 2 can harvest the visible, full-spectrum, and near-infrared light. • The Fe-doped Bi 12 O 17 Cl 2 performs enhanced photocatalytic degradation activity of water pollutant. Full-spectrum responsive and effective charge separation efficiency are still important factors for enhanced photocatalytic activity. Herein, a one-dimensional Bi 12 O 17 Cl 2 nanotube (Fe-Bi 12 O 17 Cl 2) has been synthesized successfully, which could simultaneously expand the ability of light absorption and charge separation. As the results, Fe-Bi 12 O 17 Cl 2 could realize the degradation of rhodamine B (RhB) pollutants under near-infrared and full-spectrum light irradiation, and compared with Bi 12 O 17 Cl 2 nanotube, the photocatalytic performance was improved by 3.49 and 1.93 times, respectively. Mechanism studies have shown that the Fe-doped strategy could introduce variable valence Fe3+, forming a Fe2+/Fe3+ cycle, which promotes efficient charge transfer and further enhances the activity of the photocatalytic reaction. Overall, this work provides new sight into the design of high-performance photocatalysts. [ABSTRACT FROM AUTHOR]

ZnO and Fe-doped ZnO thin films are prepared on glass substrate by sol-gel method, and the surface morphology, structure and optical property are analyzed by scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-Vis-NIR spectrophotometer. The results show that both films have a smooth surface and a hexagonal wurtzite structure with orienting along the (101) plane. Compared with the ZnO film, the surface of Fe-doped ZnO film becomes smoother, and its grain size decreases from 58.512 nm of the ZnO film to 36.460 nm. Moreover, after Fe doping, the orientation degree of (101) plane is weakened, and the optical band gap energy increases from 3.1 eV of the ZnO film to 3.4 eV.

Iron is one of the trace elements required by human body, and its deficiency can lead to abnormal bone metabolism. In this study, the effect of iron ions on the properties of tricalcium silicate bone cement (Fe/C3Ss) was investigated. It effectively solved the problems of high pH value and low biological activity of calcium silicate bone cement. The mechanical properties, in vitro mineralization ability and biocompatibility of the materials were systematically characterized. The results indicate that tricalcium silicate bone cement containing 5 mol% iron displayed good self-setting ability, mechanical properties and biodegradation performance in vitro. Compared with pure calcium silicate bone cement (C3Ss), Fe/C3Ss showed lower pH value (8.80) and higher porosity (45%), which was suitable for subsequent cell growth. Immersion test in vitro also confirmed its good ability to induce hydroxyapatite formation. Furthermore, cell culture experiments performed with Fe/C3Ss ion extracts clearly stated that the material had excellent cell proliferation abilities compared to C3Ss and low toxicity. The findings reveal that iron-doped tricalcium silicate bone cement is a promising bioactive material in bone repair applications.

Undoped and Fe-doped NiO nanoparticles were successfully synthesized using a lyophilization method and systematically characterized through magnetization techniques over a wide temperature range, with varying intensity and frequency of the applied magnetic fields. The Ni 1-x Fe x O nanoparticles can be described by a core-shell model, which reveals that Fe doping enhances exchange interactions in correlation with nanoparticle size reduction. The nanoparticles exhibit a superparamagnetic blocking transition, primarily attributed to their cores, at temperatures ranging from above room temperature to low temperatures, depending on the Fe-doping level and sample synthesis temperature. The nanoparticle shells also exhibit a transition at low temperatures, in this case to a cluster-glass-like state, caused by the dipolar magnetic interactions between the net magnetic moments of the clusters. Their freezing temperature shifts to higher temperatures as the Fe-doping level increases. The existence of an exchange bias interaction was observed, thus validating the core-shell model proposed., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 Published by Elsevier Ltd.)

Abstract SnO 2 is an appealing anode material for lithium ion batteries. Advantages of SnO 2 includes relatively low charge-discharge plateau and highly abundance in nature. However, the volume change (300%) is significant and critically impeding its cycle life. In this manuscript, we address these problems by exploiting an in-situ redox process to prepare graphene encapsulated SnO 2 nanoparticles using soluble Sn2+ as the Sn precursor, which is oxidized to SnO 2 by using graphene oxide. This method affords graphene @ SnO 2 via oxygen bridging through of SnO 2 nanoparticles. Furthermore, this method incorporates Fe atom into the SnO 2 structure in-situ to create Fe x Sn 1-x O 2 structure, which exhibits higher Li storage capacity. Our synthetic approach delivers graphene encapsulated Fe x Sn 1-x O 2 structure, which is located on flexible carbonaceous fibers, and the whole system can be applied as lithium-ion batteries anode without any need of a current collector or binder polymer. This novel Sn based electrode could deliver a high capacity (calculate total electrode mass) of 454.3 mAh g−1 after 200 cycles at 100 mA g−1 (65.1% retention). Unlike most contemporary technologies, increasing the thickness of our Sn based electrode simply increases the capacity proportionally. The areal capacity is 1348.3 μAh cm−2, and it is simply doubled to 2856.1 μAh cm−2 while we double the thickness of electrode. Highlights • Fe doping and Fe 3 O 4 hybridizing with SnO 2 composites are synthesized by facile approach. • Fe content influence the crystalline structure and morphology. • Assembling of free-standing and binder-free electrode for lithium-ions batteries. • Fe doping have better electrochemical performance than Fe 3 O 4 hybridizing with SnO 2. [ABSTRACT FROM AUTHOR]

Graphical abstract Fe-doped Bi 2 O 2 CO 3 nanoplates were developed as visible-light driven photocatalysts with tailorable energy bandgaps. The Fe-doping in Bi 2 O 2 CO 3 can greatly enhance the photocatalytic degradation of RhB upon visible-light irradiation. Highlights • Fe-doped Bi 2 O 2 CO 3 nanoplates were prepared using a solvothermal method. • Fe doping in Bi 2 O 2 CO 3 was found to greatly decrease the corresponding band gap energy. • The photocatalytic activity of Fe-doped Bi 2 O 2 CO 3 was significantly enhanced in the photocatalytic degradation of RhB. Abstract In this study, Fe-doped Bi 2 O 2 CO 3 nanoplates were fabricated using a facile solvothermal approach. The successful substitution of Bi3+ by Fe3+ was identified by a shift in the (010) diffraction peak of Bi 2 O 2 CO 3 at 2θ = 30.2°. A controllable amount of Fe doping in Bi 2 O 2 CO 3 was utilized to gradually tailor the band gap energy from 3.39 eV to 2.68 eV, resulting in the absorption edge switched from ultraviolet light to visible-light region. Compared to the pure Bi 2 O 2 CO 3 , Fe-doped Bi 2 O 2 CO 3 nanoplates exhibited an enhanced visible-light photocatalytic activity. With the gradual increase of Fe dopant amount, the photocatlytic activity of Fe-doped Bi 2 O 2 CO 3 increased initially, and then slightly decreased. Further reactive species trapping experiments demonstrated that holes (h+) and superoxide anion radicals ( O 2 −) played important roles in the photocatalytic oxidation. [ABSTRACT FROM AUTHOR]

Fe-doped δ-MnO 2 nanoneedles have been successfully synthesized via a hydrothermal method as electrode materials. The morphologies of as-synthesized samples were characterized by SEM and the role of Fe 3+ as a structure directing agent on the formation of MnO 2 nanoneedles was investigated. The electrode exhibits maximum specific capacitance of 627.3 F g −1 at a current density of 1 A g −1 , far exceeding the capacity of MnO 2 monomers. Furthermore, the capacitance retention was measured to be 94.2% after 3000 cycles, showing remarkable cycling stability. The activation of Fe 3+ in δ-MnO 2 nanoneedles attributes to the enhancement of electrode conductivity and electrochemical performance. In principle, the results indicate the potential application of our samples in supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

This study employed first principles calculations to investigate Fe-doped Bi4O5Br2 as a potential photocatalyst with high efficiency. Based on formation energy calculation, the Fe atoms prefer to replace the Bi atoms with coordination bond of 3, and the optimal concentration for Fe-doping is 6.06 wt.%. From surface energy calculations, the (1 0 1 ̄) surface has the lowest surface energy, and therefore the easiest cleavage facet is { 1 0 1 ̄ }. The key factors for the improvement of photocatalytic efficiency after Fe-doped Bi4O5Br2 are estimated as follows. First, the band gap decreases from 2.63 eV in pristine case to 2.40 eV in 4 Fe-doped Bi4O5Br2 case, resulting in the photon absorption edge shift to lower energy range and the absorption coefficient increase. Secondly, the work functions decrease from 5.66 eV (pristine) to 4.92 eV (4 Fe-doped Bi4O5Br2), which facilitate the electrons escaping from the surface. Thirdly, the relative mass ratio of photo-induced electrons and holes increases with Fe concentration. Because the Fe 3 d impurity states in the forbidden band gap become wider, the relative ratio increased after Fe-doped Bi4O5Br2. Finally, the Fe doping process introduces more active sites on the surface, which can effectively improve the capacity of target molecules adsorption. Therefore, it is reasonable to believe that Fe-doped Bi4O5Br2 can effectively improve the photocatalytic efficiency because the abovementioned key factors have tremendously improved. Our work provides a reasonable reason for choosing Fe as a dopant, which can help our experimental work and provide explanation for photocatalytic efficiency improvement. The band gap decrease induce more photon absorption in lower energy range. The relative effective mass ratio of e–/h+ increase, result in higher separation efficiency. The Fe dope introduce more and stronger active sites. [ABSTRACT FROM AUTHOR]

The NiO nanosheets assembled hollow spheres have been synthesized by a facile precipitation method using SiO 2 spheres as hard template, and the Fe was doped into NiO to improve the sensing properties of triethylamine (TEA). The structure, morphology and gas sensing properties of undoped and doped NiO were characterized by various analysis methods. The results show that the NiO microspheres have large specific surface, and excellent sensing response to 10 ppm triethylamine, so, it is a promising sensing material for detection of TEA. [ABSTRACT FROM AUTHOR]

An eco-friendly promising strategy for the synthesis of biomass-derived ordered mesoporous carbon (BOMC) and Fe-doped BOMC (Fe/BOMC) using bayberry kernel as carbon precursor have been developed via liquidation and subsequent soft-templating synthesis. The obtained BOMC presents a 3D interconnected ordered mesoporous framework with big surface area. Spectroscopy analysis shows various Fe nanoparticles including zero Fe, Fe 2 O 3 and Fe 3 O 4 are successfully embedded, penetrating the interconnected micro/mesopore framework. Fe/BOMC still remains the ordered structure with high surface area (1012m 2 /g), mesopore volume (0.95cm 3 /g) and micropore volume (0.35cm 3 /g). Interestingly, the introduction of Fe increases the oxygen content and generates more oxygen-containing functional groups such as C O group and C O bands, which further enhances the active of adsorption sites, resulting in the higher adsorption of Pb(II) and Cr(III) on Fe/BOMC. The maximum adsorption amount of Pb(II) and Cr(III) adsorption increases by 18% and 21% to 123 mg/g and 46 mg/g, respectively. Moreover, 80% of the adsorption equilibrium amount is obtained at 15 min. The results demonstrate a cost-effective and environmental-friendly strategy for synthesizing bayberry kernel-derived Fe-doped ordered OMC with rich micro/mesopores, active iron and oxygen-containing functional groups for Pb(II) and Cr(III) adsorption. [ABSTRACT FROM AUTHOR]

BaFe x Ti 2-x O 5 (x = 0, 0.004, 0.008, 0.012) thin films were prepared on Pt/Ti/SiO 2 /(100)Si substrates via sol-gel process. The phase transition behavior of the BaTi 2 O 5 thin film was investigated using temperature dependent dielectric measurements in conjunction with temperature dependent Raman spectra. Diffuse phase transition was found in BaTi 2 O 5 thin film which exhibited a broad peak without frequency dependence on the ε versus T , ε ( T ), curves around 370 °C. As the Fe content increased, a broad near-plateau dielectric permittivity maximum occurred in a wide temperature range. For x = 0.012, the value of the broad permittivity maximum was 875 at 100 kHz in the temperature range of 150–300 °C. It means that the Fe-doped BaTi 2 O 5 thin films exhibited enhanced diffuse phase transition behavior. The wide temperature stability of dielectric permittivity was obtained in the Fe-doped BaTi 2 O 5 thin films, which are promising in the high-temperature application. [ABSTRACT FROM AUTHOR]

The current work describes the fabrication of Fe-doped zinc oxide thin films on a glass substrate using sol-gel spin coating technique. The undoped and Fe-doped ZnO films were annealed at the 400 °C for 3 h. The structural, optical, morphological and luminescent features were explored by using X-ray diffraction (XRD), diffuse reflectance, scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy techniques. It was noted that XRD patterns showed the polycrystalline nature and demonstrated a hexagonal wurtzite structure of Zn 1-x Fe x O. With the rise in Fe ratio, the grain sizes of the deposited films start to cut as revealed from the SEM images. Interestingly, no variation has been noted in the transmittance value in the visible region. However, a lessening in the band-gap energy with an increment in the Fe concentration has been seen. PL curves exhibit ultraviolet emission peaks at 398 and 485 nm that are associated with the near band edge emission (NBE) and defect emission peak. It has been noted that the NBE emission shifts to longer energy with the rise in the Fe ratio. These results demonstrated the applicability of ZnO thin films as a suitable material for light emitting applications. [ABSTRACT FROM AUTHOR]

In this study, undoped and 1 wt.% Fe-doped with ZnO, and TiO nanostructures were synthesized by a simple hydrothermal method without using templates. The influence of the Fe dopant on structural, optical and electrochemical response was studied by x-ray diffraction, scanning electron microscopy, UV-Vis spectra, photoluminescence spectra and electrochemical characterization system. The electrochemical response of the carbon paste electrode modified with synthesized nanostructures (undoped ZnO and TiO as well as doped with Fe ions) toward levodopa (L-Dopa) was studied. Cyclic voltammetry using provided modified electrodes showed electro-catalytic properties for electro-oxidation of L-Dopa and a significant reduction was observed in the anodic overvoltage compared to the bare electrode. The results indicated the presence of the sufficient dopants. The best response was obtained in terms of the current enhancement, overvoltage reduction, and reversibility improvement of the L-Dopa oxidation reaction under experimental conditions by the modified electrode with TiO nanoparticles doped with Fe ions. [ABSTRACT FROM AUTHOR]