Fe2TiO5 Nanoparticles Research Articles

Design and Optimization of FeVO4/Fe2TiO5 Heterojunction Photoanode for Efficient Photoelectrochemical Water Splitting

In this study, we have successfully created nanopebble structure of FeVO4 (FVO) on FTO substrate by an in-situ solid-state transformation of hydrothermally grown FeOOH nanostructured thin film. A novel heterojunction has been created through the dropcoating of Fe2TiO5 (FTiO) nanoparticles (NPs) over the FVO nanopebble structure. Structural, morphological, and optical analyses proved that the FVO/FTiO composite had formed. XPS showed oxygen vacancies within the heterojunction. Photoelectrochemical (PEC) and photoluminescence measurements verified enhanced charge separation and carrier transport. Notably, an optimum coating of FTiO NPs exhibited an impressive photocurrent measure of 0.7 mA cm-2 at 1.6 V vs VRHE in 0.1 M KPi electrolyte, which is 2.35 fold stronger compared to the performance of bare FVO nanopebble thin film. Along with this the better stability of FVO/FTiO photoelectrode indicates the enhanced performance of the FVO/FTiO heterojunction. A comprehensive analysis using various techniques was conducted to delve deeper into the improved PEC performance for the above heterojunction. These included photoelectrochemical impedance spectroscopy (PEIS), Mott-Schottky curves, and band structure diagrams. These methods provide a more thorough understanding of the underlying mechanisms behind developing superior n-n heterojunction photoanodes for enhanced PEC performance.

ZnO and Fe2TiO5 nanoparticles obtained by green synthesis as active components of alginate food packaging films

The aim of this study was to develop an active alginate packaging film incorporating antioxidant Fe2TiO5 and antibacterial ZnO nanoparticles, obtained by green synthesis utilizing citrus peel waste. The average particle size was estimated as 10 nm for ZnO and 50 nm for Fe2TiO5. Films were prepared using 2.33% (w/v) sodium alginate with 0.11% (w/v) Fe2TiO5 and/or ZnO nanoparticles. The inclusion of nanoparticles resulted in a noticeable colour difference, reduced the transparency, increased UV light protection and improved thermal stability of the film. The dry matter content of the films was around 83%. Film solubility in distilled water was low (< 8%) mainly reflecting crosslinking of the alginate polymer and Ca2+-ions. The lowest swelling degree was obtained for the ZnO/Fe2TiO5 –alginate film (178%). The efficiency of these packaging films was demonstrated through preservation of strawberry freshness. Alginate packaging film with a mixture of metal oxide nanoparticles can facilitate food safety and increase food shelf life.

Graphene-wrapped Fe2TiO5 nanoparticles with enhanced performance as lithium-ion battery anode

Iron-titanium bimetallic oxide, Fe2TiO5 (FTO), is anticipated to exhibit superior electrochemical properties due to its high theoretical capacity. However, the practical large-scale utilization of FTO is severely hindered by its substantial capacity fading and subpar cycling performance. In this work, we propose a strategy to improve the electrochemical properties of FTO by carbon coating. To implement this strategy, we synthesize FTO nanoparticles (FTO NPs) coated with reduced graphene oxide (rGO) by a solvothermal method. When used as anode materials in lithium-ion batteries, FTO/rGO composite demonstrates a higher specific capacity (498.2 mAh g−1 after 100 cycles) than pristine FTO NPs, which is ascribed to the addition of rGO. The rGO with excellent conductivity facilitates efficient electron and ion transportation, and the composite structure of FTO NPs wrapped with rGO provides buffer space to alleviate the volume expansion during the charge/discharge process.

Effects of Sn and Nb Doping on the Performance of Fe2TiO5 As a Water Splitting Photocatalyst

Very recently, pseudobrookite Fe2TiO5 has been revealed as a promising photocatalyst for the oxidation half-reaction of overall water splitting. This semiconductor is inexpensive, non-toxic, possesses a relatively small band gap, and presents improved structural and photochemical features compared to other well-known photocatalysts. In this investigation, we doped the Fe2TiO5 structure with 1.0 at% tin and 1.5 at% niobium, separately, through a solvothermal method to prolong the minority carrier diffusion length and reduce charge recombination events under visible light illumination. The procedure generated single-phase Sn- and Nb-doped Fe2TiO5 nanoparticles with dimensions close to 30 nm. In both cases, optical band gap values of 2.1 eV were observed. Pristine Fe2TiO5, Sn-doped Fe2TiO5, and Nb-doped Fe2TiO5 were irradiated by a Xe lamp (λ>400 nm), producing 59.2, 297.6 and 344.0 mmol h-1 g-1 of O2, respectively. This result reflects the substantial improvement that doping Fe2TiO5 with Sn and Nb confers to its photocatalytic water splitting activity. In addition, photoelectrochemical measurements in a 1 M NaOH electrolyte indicated photocurrent increments from 2.4 mA cm-2 at 1.23 VRHE, for the pristine Fe2TiO5, to 36.7 and 70.7 mA cm-2 at 1.23 VRHE for Sn- and Nb-doped Fe2TiO5, respectively, accompanied by overpotential drops of 0.04 and 0.1V. Electrochemical impedance spectroscopy indicated that reductions in the resistance for the charge carrier transfer resistance at the solid/liquid interface plays an important role for the performance improvement of the doped nanomaterials. Overall, this work illustrates how structural alterations of a potential photocatalyst can improve photochemical energy conversion. The authors acknowledge support from FAPESP (Grant 2017/11986-5) and Shell and the strategic importance of the support given by ANP (Brazil’s National Oil, Natural Gas and Biofuels Agency) through the R&D levy regulation.

Antioxidant and cell-friendly Fe2TiO5 nanoparticles for food packaging application

An emerging technology of active packaging enables prolongation of food shelf life by limiting the oxygen transfer and the reactivity of free radicals, which both destruct food freshness. In this work, Fe2TiO5 nanoparticles were synthesized using a modified sol–gel method and evaluated as an enforcement of alginate food packaging film. Pure phase Fe2TiO5 nanoparticles had an average particle size of 44 nm and rhombohedral morphology. Fe2TiO5 nanoparticles induce no cell damage of human Caco-2 epithelial cells and show no inhibitory effect towards growth of a panel of bacterial strains, suggesting good biocompatibility. Films obtained by incorporation of Fe2TiO5 nanoparticles into alginate using the solvent casting method show no migration of iron or titanium ions from films to food simulants again suggesting their safety as a packaging material. Fe2TiO5 nanoparticles also showed strong antioxidant efficiency as determined using the DPPḢ assay, and confirmed further in a preservation test on fresh fruit.

Antioxidant and cell-friendly Fe2TiO5 nanoparticles for food packaging application

Antioxidant and cell-friendly Fe2TiO5 nanoparticles for food packaging application

Binary Transition Metal NiFeOx and CoFeOx Cocatalysts Boost the Photodriven Water Oxidation over Fe2TiO5 Nanoparticles

AbstractAlthough achieving a perfect match between a cocatalyst and a photocatalyst is challenging, it is a key factor to maximize the production of solar fuels. Herein, the nanostructured binary transition metal oxides NiFeOx and CoFeOx, loaded through magnetron sputtering deposition, were employed as cocatalysts for Fe2TiO5 nanoparticles, applied to the oxygen production from solar water splitting. After the coverage of Fe2TiO5 with exceptionally small CoFeOx and NiFeOx nanoparticles, the O2 evolution boosted from 7.0 (pure Fe2TiO5) to 56.0 and 63.0 μmol, respectively, under visible light irradiation. To the best of our knowledge, these performance enhancements are the highest reported for the particulate Fe2TiO5 photocatalyst, so far. The improvements result from the alleviation of charge transfer resistance at the solid/liquid interface, as the binary metal oxides aid the charge carriers separation at the heterojunctions and improve the kinetics of the water oxidation reaction.

Iron/titanium oxide-biochar (Fe2TiO5/BC): A versatile adsorbent/photocatalyst for aqueous Cr(VI), Pb2+, F- and methylene blue

This is the first report of the metal Fe-Ti oxide/biochar (Fe2TiO5/BC) composite for simultaneous removal of aqueous Pb2+, Cr6+, F- and methylene blue (MB). Primary Fe2TiO5 nano particles and aggregates were dispersed on a high surface area Douglas fir BC (∼700 m2/g) by a simple chemical co-precipitation method using FeCl3 and TiO(acac)2 salts treated by base and heated to 80 °C. This was followed by calcination at 500 °C. This method previously was used without BC to make the neat mixed oxide Fe2TiO5, exhibiting a lower energy band gap than TiO2. Adsorption of Cr(VI), Pb(II), fluoride, and MB on Fe2TiO5/BC was studied as a function of pH, equilibrium time, initial adsorbate concentration, and temperature. Adsorption isotherm studies were conducted at 5, 25, and 45 ℃ and kinetics for all four adsorbates followed the pseudo second order model. Maximum Langmuir adsorption capacities for Pb2+, Cr6+, F- and MB at their initial pH values were 141 (pH 2), 200 (pH 5), 36 (pH 6) and 229 (pH 6) mg/g at 45 ℃ and 114, 180, 26 and 210 mg/g at 25 ℃, respectively. MB was removed from the water on Fe2TiO5/BC by synergistic adsorption and photocatalytic degradation at pH 3 and 6 under UV (365 nm) light irradiation. Cr6+, Pb2+, F-, and MB each exhibited excellent removal capacities in the presence of eight different competitive ions in simulated water samples. The removal mechanisms on Fe2TiO5/BC and various competitive ion interactions were proposed. Some iron ion leaching at pH 3 catalyzed Photo-Fenton destruction of MB. Fe2TiO5, BC, and Fe2TiO5/BC bandgaps were studied to help understand photocatalysis of MB and to advance supported metal oxide photodegradation using smaller energy band gaps than the larger bandgap of TiO2 for water treatment. A long range goal is to photocatalytically destroy some sorbates with adsorbents to avoid the need for regeneration steps.

Novel proton conducting core\u2013shell PAMPS-PVBS@Fe2TiO5 nanoparticles as a reinforcement for SPEEK based membranes

In this study, new nanocomposite membranes from sulfonated poly (ether ether ketone) (SPEEK) and proton-conducting Fe2TiO5 nanoparticles are prepared by the solution casting method. Sulfonated core–shell Fe2TiO5 nanoparticles are synthesized by redox polymerization. Therefore, 4-Vinyl benzene sulfonate (VBS) and 2-acrylamide-2-methyl-1-propane sulfonic acid (AMPS) are grafted on the surface of nanoparticles through radical polymerization. The different amounts of hybrid nanoparticles (PAMPS@Fe2TiO5 and PVBS@Fe2TiO5) are incorporated into the SPEEK matrix. The results show higher proton conductivity for all prepared nanocomposites than that of the SPEEK membrane. Embedding the sulfonated Fe2TiO5 nanoparticles into the SPEEK membrane improves proton conductivity by creating the new proton conducting sites. Besides, the nanocomposite membranes showed improved mechanical and dimensional stability in comparison with that of the SPEEK membrane. Also, the membranes including 2 wt% of PAMPS@Fe2TiO5 and PVBS@Fe2TiO5 nanoparticles indicate the maximum power density of 247 mW cm−2 and 226 mW cm−2 at 80 °C, respectively, which is higher than that of for the pristine membrane. Our prepared membranes have the potential for application in polymer electrolyte fuel cells.

Photocatalytic degradation of methylene blue under natural sunlight using iron titanate nanoparticles prepared by a modified sol-gel method.

The aim of this work was to synthesize semiconducting oxide nanoparticles using a simple method with low production cost to be applied in natural sunlight for photocatalytic degradation of pollutants in waste water. Iron titanate (Fe2TiO5) nanoparticles with an orthorhombic structure were successfully synthesized using a modified sol–gel method and calcination at 750°C. The as-prepared Fe2TiO5 nanoparticles exhibited a moderate specific surface area. The mesoporous Fe2TiO5 nanoparticles possessed strong absorption in the visible-light region and the band gap was estimated to be around 2.16 eV. The photocatalytic activity was evaluated by the degradation of methylene blue under natural sunlight. The effect of parameters such as the amount of catalyst, initial concentration of the dye and pH of the dye solution on the removal efficiency of methylene blue was investigated. Fe2TiO5 showed high degradation efficiency in a strong alkaline medium that can be the result of the facilitated formation of OH radicals due to an increased concentration of hydroxyl ions.

Fabrication of Heterostructured Fe2 TiO5 -TiO2 Nanocages with Enhanced Photoelectrochemical Performance for Solar Energy Conversion.

Photocatalysts with well-designed compositions and structures are desirable for achieving highly efficient solar-to-chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe2 TiO5 -TiO2 nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL-125(Ti) nanodisks (NDs) to Ti-Fe-O NCs, which are further converted to Fe2 TiO5 -TiO2 NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe2 TiO5 -TiO2 NCs show enhanced performance for PEC water oxidation compared with TiO2 NDs, Fe2 TiO5 nanoparticles (NPs) and Fe2 TiO5 -TiO2 NPs.

Fabrication of Heterostructured Fe2TiO5–TiO2 Nanocages with Enhanced Photoelectrochemical Performance for Solar Energy Conversion

AbstractPhotocatalysts with well‐designed compositions and structures are desirable for achieving highly efficient solar‐to‐chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe2TiO5–TiO2 nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL‐125(Ti) nanodisks (NDs) to Ti–Fe–O NCs, which are further converted to Fe2TiO5–TiO2 NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe2TiO5–TiO2 NCs show enhanced performance for PEC water oxidation compared with TiO2 NDs, Fe2TiO5 nanoparticles (NPs) and Fe2TiO5–TiO2 NPs.

Electron beam-induced morphology transformations of Fe2TiO5 nanoparticles

Time-resolved morphological evolution of Fe2TiO5 nanoparticles produced with addition of polyvinyl-pyrrolidone under the electron beam irradiation.

Surface modification of Fe2TiO5 nanoparticles by silane coupling agent: Synthesis and application in proton exchange composite membranes

Modifying surfaces of nanoparticles with silane coupling agent provides a simple method to alter their surface properties and improve their dispersibility in organic solvents and polymer matrix. Fe2TiO5 nanoparticles (IT) were modified with 3-aminopropyltriethoxysilane (APTES) as novel reinforcing filler for proton exchange membranes. The main operating parameters such as reaction time (R.T), APTES/IT and triethylamine (TEA)/IT ratios have been optimized for maximum grafting efficiency. The optimum conditions for R.T, APTES/IT and TEA/IT ratios were 6h, 4 and 0.3 respectively. It was observed that the APTES/IT and TEA/IT ratios were the most significant parameters affecting the grafting percentage. Modified nanoparticles were characterized using FT-IR, TGA, SEM, TEM and XRD techniques. Effects of modified nanoparticles in proton exchange membrane fuel cells (PEMFC) were evaluated. The resulting nanocomposite membranes exhibited higher proton conductivity in comparison with pristine SPPEK and SPPEK/IT membranes. This increase is attributed to connectivity of the water channels which creates more direct pathways for proton transport. Composite membrane with 3% AIT (6.46% grafting amount) showed 0.024Scm−1 proton conductivity at 25°C and 149mWcm−2 power density (at 0.5V) at 80°C which were about 243% and 51%, respectively higher than that of pure SPPEK.

Preparation and physicochemical performance study of proton exchange membranes based on phenyl sulfonated graphene oxide nanosheets decorated with iron titanate nanoparticles

Usage of phenyl sulfonated graphene oxide (SGO) as a support material for the dispersion of iron titanate (Fe2TiO5) nanoparticles presents new methods to develop advanced composite materials for proton exchange membranes. Fe2TiO5 nanoparticles were deposited onto graphene oxide (GO) nanosheets by means of one-step solvothermal method. The novel SGO/Fe2TiO5 hybrid material dispersed in poly(vinyl alcohol) (PVA) matrix in order to fabricate thin film membranes by solution casting method. Proton conductivity and methanol permeability of nanocomposite membranes were tested to expose their potential for direct methanol fuel cell (DMFC) application. The results showed that the nanocomposite membrane containing SGO/Fe2TiO5 (5 wt %) can yield a high proton conductivity (σ = 0.061 S cm−1), low methanol permeability (P = 4.78 × 10−6 cm2 s−1) and good power density (PD = 20.47 mW cm−2) at 30 °C. The membrane's performance evaluated from the ion exchange capacity, water uptake, methanol permeability, proton conductivity and mechanical and thermal properties demonstrated the role of Fe2TiO5/SGO nanosheets as an effective hybrid material in the development of proton exchange membranes.

Experimental study and modeling of proton conductivity of phosphoric acid doped PBI-Fe2TiO5 nanocomposite membranes for using in high temperature proton exchange membrane fuel cell (HT-PEMFC)

In this study, phosphoric acid doped PBI-Fe2TiO5 nanocomposite membranes were prepared by dispersion of various amounts of Fe2TiO5 nanoparticles in PBI polymer matrix followed by phosphoric acid doping and they were applied into high temperature proton exchange membrane fuel cells (HT-PEMFCs). Effects of phosphoric acid doping level (PAdop), Fe2TiO5 mass fraction (Wd), and temperature on proton conductivity of the membranes were evaluated. The highest proton conductivity of 0.078 S/cm was obtained for the membranes containing 4 wt% of Fe2TiO5 nanoparticles with the highest value of phosphoric acid doping level (PAdop). Furthermore, a simple semi-empirical model was developed to predict the proton conductivity of the nanocomposite membranes at elevated temperatures (100–180 °C) and dry conditions. The effects of PAdop, Wd, and temperature on proton conductivity of the membranes were accounted in the model. The model was defined based on the volume fraction of free phosphoric acid inside the nanocomposite membrane structure which showed to be a determining factor in proton conduction of the membranes. The obtained proton conductivities by the model at various temperatures and phosphoric acid doping levels were in good agreement with the experimental results (average relative error <4%), indicating the reliability of the model.

Synthesis and characterization of the iron titanate nanoparticles via a green method and its photocatalyst application

Pure iron titanate (Fe2TiO5) nanoparticles were successfully synthesized via novel sol–gel method with the aid of Fe(NO3)3·9H2O, Ti(OC4H9)4 (TNBT), and glucose without adding external surfactant. Moreover, glucose plays role as reducing agent, and natural template in the synthesis Fe2TiO5 nanoparticles. The structural, morphological and optical properties of as obtained products were characterized by techniques such X-ray diffraction, energy dispersive X-ray microanalysis, scanning electron microscopy, and ultraviolet–visible spectroscopy. The samples indicated a paramagnetic behavior, as evidenced by using vibrating sample magnetometer at room temperature. To evaluate the photocatalyst properties of nanocrystalline iron titanate, the photocatalytic degradation of methyl orange under ultraviolet light irradiation was carried out.

Novel nanocomposite membranes based on polybenzimidazole and Fe2TiO5 nanoparticles for proton exchange membrane fuel cells

In this work, Fe2TiO5 nanoparticles were used for improving the proton conductivity, and water and acid uptake of polybenzimidazole (PBI)-based proton exchange membranes. The nanocomposite membranes have been prepared using different amounts of Fe2TiO5 nanoparticles and dispersed into a PBI membrane with the solution-casting method. The prepared membranes were then physico-chemically and electrochemically characterized for use as electrolytes in high-temperature PEMFCs. The PBI/Fe2TiO5 membranes (PFT) showed a higher acid uptake and proton conductivity compared with the pure PBI membranes. The highest acid uptake (156 %) and proton conductivity (78 mS/cm at 180 °C) were observed for the PBI nanocomposite membranes containing 4 wt% of Fe2TiO5 nanoparticles (PFT4). The PFT4 composite membrane showed 380 mW/cm2 power density and 760 mA/cm2 current density in 0.5 V at 180 °C at dry condition. The above results indicated that the PFT4 nanocomposite membranes could be utilized as proton exchange membranes for high-temperature fuel cells.

Synthesis and characterization of Fe2TiO5 nanoparticles through a sol–gel method and its photocatalyst applications

A novel modified sol–gel method was used in order to synthesize of Fe2TiO5 nanoparticles with aid of Fe(NO3)3·9H2O and Ti(OC3H7)4 as the starting reagents in the presence of ethanol as the solvent. To the best of author knowledge, it is first time that oxalic acid was used as a chilate agent in produce Fe2TiO5 nanoparticles. Besides, to examine the effect of different surfactants such as oleic acid, oleylamine, sodium dodecyl sulfate and cetyltrimethylammonium bromide on the particle size of final products several tests were performed. The as-synthesized Fe2TiO5 nanoparticle was utilized as photocatalyst for decolorisation of Rhodamine-B (RhB) and Methylen blue (MB) to investigate its light harvesting application. The photocatalyst results reveal that the maximum decolorization of 93 and 95 % for RhB and MB occurred with Fe2TiO5 nanoparticle catalyst in 40 min of reaction time under ultraviolet light irradiation, respectively.

Nanocomposite proton exchange membranes based on Nafion containing Fe2TiO5 nanoparticles in water and alcohol environments for PEMFC

In this study, the preparation and characterization of Nafion/Fe2TiO5 nanocomposite membranes for proton exchange membrane fuel cells (PEMFCs) were investigated. Nafion/Fe2TiO5 nanocomposite membranes were prepared by dispersion of Fe2TiO5 nanoparticles within the pure commercial Nafion membranes. The composition percentage of the nanocomposite membranes and the solvent used for the dispersion of nanoparticles within the membranes were varied in order to study the effect of these variations on the proton conductivity, water uptake and also the thermal stability of the membranes. The nanocomposites membranes were characterized by using thermogravimetric analysis (TGA), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) spectroscopy and impedance spectroscopy (IS). The prepared Fe2TiO5 nanocomposite membranes showed a higher water uptake, proton conductivity and thermal stability compared with the pure commercial Nafion membranes. The highest proton conductivity (226mS/cm) was observed for the membranes containing 2wt% of Fe2TiO5 nanoparticles and prepared in de-ionized water (DI) as solvent.