Edge-decorated platinum quantum dots on hexagonal iron titanate nanostructures as bifunctional HER and OER electrocatalyst in alkaline water electrolysis

ABSTRACT Towards fabricating cellulose nanocrystalline‐based biodegradable multifunctional bio‐composites, polyvinyl alcohol (PVA), cellulose nanocrystal (CNC), and barium iron titanate (BaFe 0.5 Ti 0.5 O 3 (BTF)) nanoparticles were reinforced into the polymer matrix. A chemical polymerization process was applied for fabricating BTF nanoparticles and cellulose nanocrystalline‐PVA@ BTF nanocomposites. Uniformly distributed BTF nanoparticles within a cellulose nanocrystalline–PVA matrix improve the structural, dielectric, and antimicrobial properties, proving the reinforcement effect of BTF addition. The bio‐nanocomposites demonstrated that the BTF nanoparticles facilitated the formation of hydroxyapatite‐like phases and enhanced the interaction between the polymer and filler. This was studied following a process involving simulated body fluid. The effects of adding BTF nanoparticles were analyzed using techniques such as X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dielectric measurements. Incorporation of BTF NPs enhances the dielectric constant by increasing interfacial polarization, whereas rising temperature further amplifies dielectric behavior by activating charge carriers. The immersion in simulated body fluid (SBF) confirmed the conception of hydroxyapatite‐like segments, mainly with higher BTF‐ratio samples, confirming the bioactivity of the composites. These multifunctional nanocomposites offer promising potential for applications in bioelectronics and bone tissue engineering.

Abstract The effect of iron doping on the conductivity of sodium titanate, a material suitable for its purported use in sodium‐ion batteries, was explored. The sodium titanate and sodium iron titanate materials were prepared by a simple sol–gel aqueous coprecipitation route, followed by calcination at 1273 K. The material was characterized using thermogravimetric‐differential thermal analysis (TG‐DTA) for understanding the thermal decomposition behavior, X‐ray diffraction (XRD) for the crystalline phase composition analysis, scanning electron microscopy (SEM) for understanding the surface morphology and homogeneity of the phases and X‐ray photoelectron spectroscopy (XPS) for establishing the oxidation states of different ions. The electrochemical impedance spectroscopy (EIS) studies revealed an increase in total conductivity at low levels of iron doping. The activation energy of conduction was derived to be approximately 0.2–0.3 eV, which was significantly lower than the reported values for undoped sodium titanates, 0.7 eV for Na 2 Ti 3 O 7 and 0.9 eV for Na 2 Ti 6 O 13 , indicating enhanced ionic conductivity upon iron incorporation. Overall, the findings of this study provide a fundamental understanding of the variation in conductivity of sodium iron titanate with iron concentration and its correlations with different crystalline phases.

Depth exploration of gadolinium-modified bismuth iron titanate: A comprehensive investigation

Morphologically controlled tuning of structural, magnetic and impedance properties of iron titanate (FeTiO3) for multilayered structures

Iron titanate (FeTiO3) nanoparticles were synthesised with three distinct Ti weight percentages and a constant Fe weight. These characterised nanoparticles were utilised as adsorbents to extract lead (II) from aqueous solutions. An atomic absorption spectrophotometer (AAS) was used to estimate the percentage of ion elimination. In all investigations, FeTi-2.0 NPs showed efficient adsorption behaviour (SBET =199.1 m2g -1) for the removal of Pb (II) ions. The Nano catalyst had the highest adsorption capacity (qe, mg/g) in the Freundlich adsorption isotherm, and when the temperature (K) increased, the highest adsorption capacity was seen at 333 K (60°C). The adsorption process was found to be spontaneous and endothermic (∆Go = -8.43 kJ/mole; ∆Ho = 7.88 kJ/mole) under established conditions.

Study of ilmenite and zero valent iron nanoparticles for persulfate activation in disinfection of wastewater

Construction of a novel Z-scheme FeTiO3/MOF-derived In2S3 catalyst for visible-light-driven photo-Fenton degradation of pollutants

Enhanced solid-electrolyte interface efficiency for practically viable hydrogen-air fuel cell systems

The rapid photocarrier recombination limits the photocatalytic activity of iron titanate (FeTiO3) to be further improved. Developing novel approaches to inhibit the rapid recombination rate of the FeTiO3 photocatalysts is crucial for efficiently degrading pollutants in wastewater. Rare earth ions, with unique electron dispositions and large ion radii, could effectively inhibit photocarrier recombination. Herein, novel lanthanum (La)-doped FeTiO3 photocatalysts were designed and successfully synthesized. The photocatalytic performance of the 12 mol % La/FeTiO3 photocatalyst was superior in degrading tetracycline hydrochloride (TCH), methylene blue (MB), and brilliant blue (BB). These degradation rate constants (k) were 0.12358, 0.01357, and 0.03064 L mg-1 min-1, respectively, which were 12.83, 1.61, and 7.78 times that of pure FeTiO3. The photoelectronic tests and density functional theory (DFT) calculations revealed that the La 4f orbital forms an impurity energy level in the conduction band of FeTiO3. This level narrows the bandgap and acts as an electron acceptor, capturing photoexcited electrons and inhibiting the rapid recombination of photoexcited electron-hole pairs in FeTiO3. This work enhances the potential of FeTiO3 in the photocatalysis field and provides important insights into the efficient degradation of organic pollutants in wastewater.

Iron titanate mixed metal oxides were synthesized by the sol–gel method through four different routes. The effect of (i) the solvent of iron precursor, (ii) the addition of the chelating agent to the titanium or iron solution and (iii) the molar ratio between the chelating agent and the titanium or iron precursor over the overall percentage of obtained iron titanates was evaluated. Fourier-transform infrared spectroscopy (FTIR) and UV–Vis spectroscopy (UV–Vis) performed on the reaction medium evidenced the formation of acetate complexes of titanium (IV) or iron (III) during the different routes. X-ray diffraction (XRD) patterns of the obtained materials showed the formation of ilmenite (FeTiO3), pseudorutile (Fe2Ti3O9) and pseudobrookite (Fe2TiO5) in different proportions, as well as hematite (Fe2O3), rutile [TiO2 (R)] and anatase [TiO2 (A)]. The materials with the highest content of iron titanates obtained in each route were characterized and evaluated in the photocatalytic degradation of cyanide using visible light irradiation. UV–Vis Diffuse Reflectance Spectroscopy (UV–Vis DRS) showed that the samples exhibited energy bandgap values between 2.31 and 2.90 eV, which agrees with the values reported for iron titanates and evidence the possible activation of the materials under visible light. Scanning electron microscopy (SEM) and nitrogen physisorption results showed that the synthesized materials exhibited nanometric particle size and lower surface area (36.7 ± 4.8 m2·g-1) than TiO2 Degussa P-25 (72–155 m2·g-1). The photocatalytic performance of the synthesized materials toward oxidation of CN− exceeded by 56% the activity of pure TiO2. The content of iron titanates in the synthesized materials was found to be the variable with the greatest influence on the photodegradation of cyanide. In addition, an inversely proportional relationship between the pseudorutile content of the materials and their photocatalytic activity was observed.

Improved cycle capability of Mn-doped Fe2TiO5 anode for lithium-ion batteries

Oxygen vacancy and Ce ion co-synergize to enhance the photocatalytic degradation performance of FeTiO3: An experimental and DFT study

Hydrogen gas is a prominent focus in pursuing renewable and clean alternative energy sources. The quest for maximizing hydrogen production yield involves the exploration of an ideal photocatalyst and the development of a simple, cost-effective technique for its generation. Iron titanate has garnered attention in this context due to its photocatalytic properties, affordability, and non-toxic nature. Over the years, different synthesis routes, different morphologies, and some modifications of iron titanate have been carried out to improve its photocatalytic performance by enhancing light absorption in the visible region, boosting charge carrier transfer, and decreasing recombination of electrons and holes. The use of iron titanate photocatalyst for hydrogen evolution reaction has seen an upward trend in recent times, and based on available findings, more can be done to improve the performance. This review paper provides a comprehensive overview of the fundamental principles of photocatalysis for hydrogen generation, encompassing the synthesis, morphology, and application of iron titanate-based photocatalysts. The discussion delves into the limitations of current methodologies and present and future perspectives for advancing iron titanate photocatalysts. By addressing these limitations and contemplating future directions, the aim is to enhance the properties of materials fabricated for photocatalytic water splitting.

Anelectrochemical sensoris established using an iron titanate (FeTiO3) modified glassy carbon electrode (GCE) to detect nitrofurazone. Various microscopic and spectroscopic analysis was performed to reveal the properties of the prepared FeTiO3 hexagonal nanoplates. The FeTiO3/GCE presents enhanced electrochemical response to nitrofurazone at the peak reduction potential of - 0.471V with a larger peak current than the bare GCE due to high electrical conductivity, enhanced specific surface area, and abundant active sites. The superior nitrofurazone detection performance includes the low limit of detection of 0.002μM and the sensitivity of 0.551 µA µM-1cm-2 in the linear concentration range of 0.01-162.2μM. The reproducibility and selectivity studies of the FeTiO3/GCE show excellent results with a relative standard deviation of < 5%. The practicability of FeTiO3/GCE is confirmed by monitoring nitrofurazone in actual samples. This work demonstrates that perovskite-type FeTiO3 has great potential in real-world sample analysis, and provides a new way to develop high-performance electrochemical sensors.

Mesoporous honeycomb iron titanate using a sol-gel, evaporation-induced self-assembly method is synthesized. A triblock copolymer, F127, serves as a structure-directing agents, with iron chloride and titanium (IV) isopropoxide as inorganic precursors. The strong intermolecular force of attraction among urea, metal precursors, and polymer led to the formation of the mesoporous honeycomb structure. The study of physicochemical properties using different techniques reveals the formation of microstructures with a remarkable degree of porosity. The amorphous iron titanate outperforms the photochemical generation of H2 due to its disorderly structural arrangement and incomplete crystal formation. The randomness on the structure provides more area for catalytic reaction by providing more contact with the reactant and superior light absorption capability. The high amount of hydrogen gas, 40.66mmolg-1h-1, is observed in the investigation over 3h of activity for the iron titanate honeycomb sample. This yield is a more significant amount compared to the obtained for the commercially available TiO2 (23.78mmolg-1h-1). The iron titanate materials synthesized with low-cost materials and methods are very effective and have the potential for hydrogen generation.

Enhanced lithium storage performance derived from Fe2Ti1-xNixO5 (0 ≤ x ≤ 0.1) as a fast charging anode

Nd substitution response on structural, dielectric, and electrical features of bismuth iron titanate

Strontium substituted sodium iron titanate as a possible sodium-ion conductor: Preliminary studies on preparation, crystalline transformation and conductivity

Recently perovskite materials have gained much attention as potential candidates for solid oxide cell (SOC) fuel electrodes due to their advantages of redox stability, coking resistance and sulfur resistance over their cermet counterparts. Enhanced electrochemical performance has also been observed for some of these perovskite materials resulting from exsolution, where nano-sized metal particles are formed on the material surface under reducing conditions. However, the degradation mechanism of these perovskite fuel electrodes has yet to be fully understood and the relationship between their long-term stability and operating envrionments (fuel-cell/electrolysis, fuel compositions, redox cycles, operating pressure, etc.) has not been fully investigated.Here, life tests were conducted in open-circuit and reversible operation at 850oC on electrolyte-supported symmetric and full cells with Ni and Ru-doped strontium iron titanate (Sr0.95Ti0.3Fe0.63Ni0.07O3 and Sr0.95Ti0.03Fe0.63Ru0.07O3) as fuel electrodes (SrTi0.3Fe0.6Co0.1O3 used as the air electrode in the full cells). For both materials, higher degradation rate was observed when operated with 97% H2 + 3% H2O compared with 50% H2 + 50% H2O as fuel; an increase in ohmic resistance and gas adsorption/desorption resistance contributed to most of the degradation observed. STFN also showed higher degradation rates than STFRu in both fuel compositions. Exsolution from both compositions was confirmed by scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) with both fuel compositions and in situ X-ray Diffraction (XRD) showed the simultaneous perovskite to Ruddlesden-Popper (RP) phase transformation. The faster perovskite-RP phase transformation is believed to be responsible for the higher degradation rates observed for cells using fuel electrode materials with less stable perovskite structure (STFN over STFRu) and tested in more reducing fuel compositions (97% H2 over 50% H2). Moreover, redox cycles were introduced for STFN and STFRu during life tests and partial performance recovery was observed; in situ XRD and SEM microstructural analysis suggests that the recovery resulted from a transformation from RP back to perovskite for both materials. Finally full cell reversible operation durability tests (6 hrs each in fuel cell and electrolysis modes at 0.8 A/cm2) conducted at 850oC with 50% H2 + 50% H2O as fuel at 1 atm showed reasonably good stability over 1000 h. Initial reversible life testing at 3 atm operating pressure showed higher degradation rates, and the possible reasons for this will be discussed.