Sol-gel Research Articles

Application of fly ash-TiO2 composites for enhanced adsorption and photocatalytic degradation of fuchsin dye.

It is important to accomplish both photocatalytic efficiency and adsorption capacity in the catalyst to produce a highly effective photocatalyst for complete dye removal from wastewater. In the current investigation, TiO2 and fly ash-TiO2 composites (0.5-5 wt%) were fabricated by sol-gel and wet-impregnation process, and their catalytic performance was evaluated for the effective adsorption and photocatalytic degradation of fuchsin blue dye. The catalysts were characterized by XRD, UV-DRS, SEM, EDS, RAMAN spectroscopy, and N2 adsorption analysis Adsorption and degradation studies were conducted to investigate factors such as pH (2 - 10), adsorbent dose (1-9mg), contact time (30-180min), and initial adsorbate concentration (5-30mg/L) to eradicate fuchsin dye from water. The 5 wt% fly ash-TiO2 catalyst showed a maximum capacity for adsorption of 20.32mg/g and 76% removal of fuchsin dye. The Langmuir isotherm model fitted well to the experimental data, whereas the adsorption process obeyed pseudo-first-order kinetics. When exposed to UV light, a 5 wt% fly ash-TiO2 composite demonstrated maximum photocatalytic degradation of 88% after 180min, followed by a pseudo-first-order kinetic model. The catalyst was easily reusable for five cycles without losing dye removal effectiveness.

Green synthesis of nitrogen-doped TiO2 nanoparticles with exposed {001} facets using Chromolaena odorata leaf extract for photodegradation of pollutants under visible light

Facet-tailored TiO2 nanoparticles (NPs) exhibit exceptional properties due to high surface energy. Conventional strategies for the fabrication of such TiO2 NPs involve harmful chemicals, which necessitates the development of environmentally benign pathways. Plant extract-assisted synthesis has emerged as a promising green alternative to conventional nanomaterial synthesis. This work introduces an innovative method for the synthesis of nitrogen-doped TiO2 (N-TiO2) NPs with exposed {001} facets using the leaf extract of a weed plant Chromolaena odorata, which is commonly known as Siam weed. The synthesis was carried out by sol-gel process with triethylamine (TEA), hydrazine hydrate and urea being the nitrogen precursors. The synthesised N-TiO2 NPs exhibited exposed {001} facets and showed a reduction in band gap. Photo-induced degradation of methylene blue dye was used to analyse the photocatalytic capability of N-TiO2 NPs in the visible range. The effect of N precursor, N dosage and light exposure time on the catalytic efficacy was studied. N-TiO2 NPs derived from TEA with 1 mol.% dopant achieved 98 % degradation in 180 minutes, while those synthesized with hydrazine and urea attained 96 % and 93 %, respectively when compared to 90 % degradation for undoped samples. The N-doping leads to significant advancement of photocatalytic effectiveness of the TiO2 NPs by introducing mid-gap levels in the forbidden energy gap that diminishes the charge carrier-recombination and boost the charge-carrier mobility of TiO2. This along with the existence of high energy facets causes a substantial advancement in the photocatalytic function in the visible region. The proposed method is a sustainable way for synthesising N-TiO2 NPs with exposed {001} facets for environment remediation applications.

Cellulose/sodium alginate gel electrolyte membranes with synergistic hydrogen bonding and metal ion coordination networks for high performance aqueous zinc-ion batteries

Cellulose has outstanding potential for application in energy storage batteries due to its high temperature resistance, high electrolyte affinity, renewability, and suppression of the shuttle effect, but single cellulose membranes still suffer from problems such as inhomogeneous pore distribution and unstable three-dimensional network structure. In this study, a green and sustainable regenerative cellulose (RC)/sodium alginate (SA) gel electrolyte membrane is developed by sol-gel process, the double crosslinked network scaffold centered on Zn2+ was constructed by the synergistic hydrogen-bonding and metal ion- coordination network, the stable and uniform pore structure was also formed. The obtained RC-SA gel electrolyte membrane exhibits outstanding performance, featuring a dual crosslinked network with abundant pore structure and numerous polar groups that effectively enhance Zn2+ transport, significantly improving battery cycling performance. The corresponding RC-SA gel electrolyte membrane demonstrates high ionic conductivity (6.30 mS·cm−1) and Zn2+ transference number (0.66), leading to excellent reversible capacity (159 mA·h·g−1) and self-discharge suppression capability (maintaining 99.2 % of capacity after a 24 h standstill) in Zn//V2O5 full-cell. The coulombic efficiency and cycling stability of the Zn//Cu half-cell and Zn//Zn symmetric cell using RC-SA gel electrolyte membrane outperforms that of the glass fiber separator, highlighting its multifunctionality and potential applications.

Structural, optical, luminescent and magnetic properties of Gd2O3 nanoparticles: A comparative study on the effect of different green fuels in the sol–gel synthesis tactics

In this study, five samples of Gd2O3 NPs (size range: 4–33 nm) were synthesized by five different green facile and diverse natural products acting as reducing & stabilizing agents such as: fresh juices of sugarcane, lemon, tomato & orange fruits and citric acid via self combustion sol–gel tactics. Powder X-ray diffraction (PXRD), High resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR) and Raman analysis affirmed cubic-C type crystal structure of Gd2O3 NPs prepared using citric acid, lemon juice and sugarcane juice. Mixed cubic and monoclinic phases were observed in Gd2O3 NPs prepared using tomato and orange juices. Notably, NPs of Gd2O3 in quantum dot regime (size: 6 ± 2 nm) were produced in the fresh sugarcane juice mediated synthesis protocol. Fresh lemon juice and sugarcane juice were appeared to be the most efficient green fuel for producing quality samples of Gd2O3 NPs. Optical absorption studies showed that bandgap in these Gd2O3 NPs is strongly dependent on the preparation protocol and type of green fuel. Interestingly, highest and lowest band gap of 4.91 eV and 4.43 eV were obtained for Gd2O3 NPs fabricated with orange and lemon juices, respectively. Photoluminescence (PL) and electron spin resonance (ESR) analysis affirmed formation of Schottky and Frenkel surface defects along with self trapped excitons and oxygen vacancies in these Gd2O3 NPs. Paramagnetic character of these Gd2O3 NPs at 300 K is validated by dc-magnetization and ESR studies. Present study demonstrated that microstructural, optical absorption and photoluminescence properties of Gd2O3 NPs can be easily customized by choice of natural products in the synthesis tactics.

Sol-Gel preparation and luminescent properties of Eu3+ doped Al2O3 hollow microspheres

Rare earth elements have attracted significant attention due to their unique electronic structure. By doping rare earth ions into oxides, they can be used as spectral conversion materials in fields such as photovoltaic power generation and biological probes. In this paper, the performance of Eu3+ doped Al2O3 hollow microspheres by sol-gel method was analyzed by SEM, XRD, IR, TG-DSC, and fluorescence spectrometer. Using aluminum isopropoxide (Al(OC3H7)3) as raw material, PMMA with a particle size of 150nm as the template, PMMA/boehmite particles with core-shell structure can be prepared by sol gel method and template method. After adding Eu3+ and heat treatment, a transition occurred from γ-AlOOH(85°C)→γ-Al2O3(600°C)→θ-Al2O3(1000°C)→α-Al2O3(1200°C) as the temperature increased, and EuAlO3 was generated at 1200°C. Eu3+ occupied the sites without inversion centers inside the host lattice, and the alumina was an effective matrix for the fluorescent properties of Eu3+. Its excitation was caused by the 7F0→5L6 transition, and its luminescence was controlled by the 5D0→7F2 transition, which can convert ultraviolet light into red and orange light. The fluorescence intensity increases with the increase of Eu3+ content, and no quenching was observed at a doping concentration of 10mol% Eu3+.

Dual-functionalized ORMOSIL nanoparticles to enhance superhydrophobicity of epoxy based coatings

Organically modified silica (ORMOSIL) nanoparticles bearing fluoro-octyl and glycidoxy-propyl groups were prepared by two simple methods: i) modification of silica (SiO2) nanoparticles with the corresponding organo-silanes and ii) sol-gel process involving tetraethoxy-silane in the presence of the organo-silanes. These hydrophobic ORMOSIL particles were mixed with epoxy resin/amino-based hardener in 2-propanol medium and sprayed on the surface of carbon-steel substrate. The epoxy coating containing ORMOSIL prepared by modification of SiO2 nanoparticle presented outstanding water repellence with water contact angle (WCA) of ≈ 162° and high roll-off ability of the water droplets. Furthermore, excellent adhesion to the substrate was evidenced by sandpaper abrasion and tape peeling test. The effect of the solid content in the 2-propanol dispersion on the superhydrophobicity character was investigated. It was observed that the spray dispersion with higher solid concentration resulted in better superhydrophobicity response, mechanical durability and effective self-cleaning behavior. The hierarchical structure and roughness were identified by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The coatings presented in this work are strong candidates for large scale production due to the low-cost and simplicity of the spraying technique and the economically feasibility of the involved compounds.

Experimental optimization for synthesis of cerium-doped titanium dioxide nanoparticles by modified sol-gel process

A systematic experimental optimization procedure was developed for the synthesis of cerium-doped titanium dioxide nanoparticles (CeTNPs) based on modified sol-gel process. The nanocomposite was prepared using titanium tetraisopropoxide (TTIP) as a catalyst precursor, while utilizing the non-ionic surfactant Triton X-114 in cyclohexane as a stabilizing agent. The synthesis process was optimized by identifying the main experimental factors that affect the properties of the nanoparticles, primarily the structural phase and particle size. The synthesized samples were characterized by X-ray diffraction (XRD) for phase and size, field emission scanning electron microscope (FE-SEM) for morphology, particle size analyzer (PSA) for size distribution, and Brunaur, Emmett, and Teller (BET) for surface area and pores characteristics. The photocatalytic activity of the optimized sample was tested for the removal of methyl orange (MO) and lead (II) from aqueous solutions, and the results indicate superior performance as the catalyst uptakes were 14.8 mg/l and 11.4 mg/l for methyl orange and lead (II), respectively.The main highlights of the proposed procedure are as follows:•Identification of the key variables impacting the structural and morphological properties.•Establishing the levels of each factor based on experimental findings.•Generation of all possible combinations of factors based on ANOVA, then characterization of the synthesized material from every possible combination.

New NASICON-type phosphates, KNbM(PO4)3 (M = Ti, V), exhibiting a reversible alkali metal intercalation

The NASICON framework is an attractive object for designing polyanion electrode materials for metal-ion batteries. Two new NASICON-structured (S.G. R-3c) niobium phosphates KNbTi(PO4)3 (a = 8.4307(1) Å, c = 23.3955(4) Å, V = 1440.11(5) Å3) and KNbV(PO4)3 (a = 8.4892(1) Å, c = 23.3042(4) Å, V = 1454.45(3) Å3) were synthesized by the Pechini sol–gel method. Rietveld refinement revealed the potassium atoms occupy only the A(1) 6-fold antiprismatic site in both structures. Nb K-edge XANES measurements confirmed the presence of Nb5+ in KNbV(PO4)3 and the mixed-valent Nb5+/4+ in KNbTi(PO4)3 phosphates. Electrochemical measurements showed that both compounds deliver the initial discharge capacity of 110–120 mAh g−1 at a C/10 rate in the Na-half cell. KNbV(PO4)3 also maintains a reversible K+ intercalation at about 1.5 V vs. K+/K with a significant hysteresis (∼0.35 V at a C/10 rate) indicating a sluggish K+ diffusion. The mobility of alkali metal ions within the framework of new phosphates is discussed in terms of bond valence site energy calculations.

Physically crosslinked chitosan/αβ–glycerophosphate hydrogels enhanced by surface-modified cyclodextrin: An efficient strategy for controlled drug release

This study reports physically crosslinked chitosan/αβ–glycerophosphate (CS/GP) hydrogels containing surface-modified cyclodextrin for efficient controlled drug release. Highly water-soluble β–cyclodextrin-grafted L–serine (CD–g–Ser) compounds were synthesized, and employed as an effective carrier of berberine hydrochloride (Ber) for CS/GP hydrogels. Various characterizations, including gelation time determination, scanning electron microscopy, and viscosity measurement, indicated that the introduction of CD–g–Ser led to increased crosslinking degree, improved temperature sensitivity, and shortened sol–gel phase transition time of the hydrogel. Meanwhile, the sustained release ability for Ber was achieved due to the hydrophobic association between cyclodextrin and Ber. It was observed that within 4 h, the hydrogel containing CD–g–Ser released 40 % of Ber, while the CS/GP hydrogel without CD–g–Ser released 65 % of Ber. Furthermore, in vitro bacteriostasis experiments confirmed the drug-loaded hydrogel had an excellent antibacterial effect against E. coli and S. aureus (diameter of the inhibition zone up to (16.4 and 34.7) mm, respectively), low hemolysis rate (<2 %), and high cell viability (>90 %). The findings indicate that the physical crosslinked CS hydrogel can be used as a new drug delivery system, and its excellent antibacterial effect makes it a potential wound dressing candidate.

Myosin supramolecular self-assembly: The crucial precursor that manipulates the covalent aggregation, emulsification and rheological properties of myosin

The transformation of molecular conformation and self-assembly properties of myosin during the heating process at different ionic strengths (0.2 M, 0.4 M and 0.6 M NaCl) and its effect on rheological behavior and emulsification properties were investigated. Under incubation temperatures between 40 °C and 50 °C, myosin underwent a supramolecular self-assembly stage dominated by noncovalent forces (hydrogen bonding, ionic bonding and hydrophobic interactions). Higher ionic strength facilitated molecular rearrangement through enhanced swelling of myosin heads and head-to-head assemblies, which contributed to enhanced ordering and homogeneity of myosin covalent aggregates (above 60 °C) and manifested itself macroscopically as enhanced gel viscoelasticity and emulsion stability. In contrast, at lower ionic strength, the tail-to-tail assemblies of myosin led to the preferential formation of covalent cross-links in the tails, which resulted in the inability of molecular rearrangement and the formation of disordered aggregates and finally led to the deterioration of the gel and the destabilization of the emulsion. In conclusion, the supramolecular self-assembly behavior of myosin, as an intermediate process in myosin’s sol–gel transition, is crucial for the orderliness of myosin assemblies, gel network strengthening, and emulsion stability. The obtained insight provides a reference for the precise implementation of quality improvement strategies for meat products.

Boosting nickel nanoferrite’s specific capacitance with Azadirachta Indica for advanced supercapacitors

Nickel Ferrite (NiFe2O4) a valuable transition metal oxide possessing a spinel structure, it is extensively utilized in industry due to its compelling properties. In this present study the sol–gel auto-combustion synthesis method was employed using nitrates and citric acid in conjunction with double distilled water (DDW) and Azadirachta Indica extract. The X-ray diffraction (XRD) analysis revealed the formation of a cubic spinel phase with high crystallinity. Crystallite size of prepared Nickel Ferrite in double distilled water and Azadirachta Indica by Scherrer’s equation and Williamson-Hall plot (W-H) are 28.09 nm and 33.01 nm as well as 16.23 nm and 16.55 nm, with microstrains of 0.32739 % and 0.339 × 10−3 % respectively. The notable reduction in the crystallite size is observed when employing Azadirachta Indica compared to the double distilled water-based synthesis. The X-ray density of the synthesized sample in double distilled water and Azadirachta Indica are obtained as 3.935 (g cm−3) and 5.427 (g cm−3). Transmission electron microscopy (TEM) of Azadirachta Indica-based nanostructured Nickel Ferrite material exhibited a particle size of 17.06 nm. The study encompassed the calculation of various parameters such as hopping lengths, polaron radius, specific surface area, packing fraction, and dislocation density. Magnetic parameters are comprehensively examined using a vibrating sample magnetometer (VSM), revealing a Bohr magneton is 3.278. The shifting of coercivity curve observed towards right due to exchange bias effect and the unidirectional anisotropy for diamagnetic Azadirachta Indica based Nickel ferrite. Optical properties are investigated through UV–VIS and Fourier-transform infrared (FTIR) spectroscopy, resulting in a band gap energy of 1.75 eV and a porosity is 11.16 %. Electrochemical evaluation of Nickel Ferrite electrodes is conducted over a potential range from 0.0 to 1 V. The specific capacitance of Nickel Ferrite electrodes synthesized with double distilled water and Azadirachta Indica are determined as 511.9 F/g and 695 F/g respectively, at a scan rate of 50 mV/s, as evaluated through cyclic voltammetry (CV) measurements in Ag/AgCl (0.1 M NaOH as electrolyte). The specific capacitance of Nickel Ferrite, produced with double distilled water and Azadirachta Indica extract, is 686 F/g and 817.398 F/g respectively, as determined by Galvanostatic charge–discharge (GCD) measurements. The study conclusively demonstrated significantly improvement in the electrochemical performance of Nickel Ferrite, synthesized with Azadirachta Indica extract for supercapacitor application. Based on GCD and CV, the specific capacitance has been boosted significantly with Azadirachta Indica extract for supercapacitor application.

Micromolar-level glucose detection using a colorimetric sensor based on imprinted polymer-coated Fe3O4 nanoparticles

The glucose concentration in the blood, commonly referred to as blood sugar level, typically ranges from 3.9 to 5.6 mmol/L. It is one of the most critical physiological parameters in the human body, requiring strict regulation to maintain proper bodily function. There is a strong demand for glucose sensors that are highly sensitive, user-friendly, and exhibit high selectivity towards glucose molecules, even in challenging environments. In this study, a colorimetric sensor based on imprinted polymer and Fe3O4 nanoparticles (NPs) was developed, enabling the detection of glucose at micromolar levels, observable by the naked eye. Fe3O4 NPs were prepared using a sol–gel method and served as cores for the deposition of polydopamine (PDA) via in situ polymerization. An imprinting process created glucose-imprinted PDA, resulting in molecular cavities on the PDA surface, with the polymeric layer approximately 25 nm thick. The surface of the Fe3O4 NPs facilitated the degradation reaction of H2O2 to produce hydroxyl radicals (•OH), which subsequently oxidized 3,3′,5,5′-Tetramethylbenzidine (TMB) to its oxidized form (TMB+), causing a color change from colorless to blue. The cavities played a crucial role in the sensing mechanism, connecting the catalytic surface of the Fe3O4 NPs to the surrounding environment. When glucose molecules occupied the cavities, the catalytic activity decreased, leading to a corresponding variation in color change depending on glucose concentration. Leveraging these advantages, the imprinted PDA was applied to detect glucose in aqueous solutions and human plasma with a limit of detection as low as 10 µM. The sensor exhibited high selectivity towards glucose over other common analytes in human blood, such as lysine, Ca2+, and K+, along with reproducibility, maintaining approximately 73 % of its sensing signal after six cycles of reuse. This study demonstrates the detection of glucose by the naked eye at micromolar levels. The detection procedure can be conducted outside of laboratory settings, presenting a highly promising approach for glucose detection in real-world applications, particularly in remote areas.

Correction: Magnetization response and magnetoelectric coupling of Mn-doped BiFeO3 thin films–microwave-assisted sol–gel approach

Correction: Magnetization response and magnetoelectric coupling of Mn-doped BiFeO3 thin films–microwave-assisted sol–gel approach

3D printed high–strength polyimide aerogel metamaterials for sound absorption and thermal insulation

The structural manufacturing of high–performance polyimide (PI) aerogels is challenging because of the insufficient mechanical strength and rheological properties of sol–gel ink, and PI aerogels have limited application. In this study, a PI aerogel–based Helmholtz resonator (PIHM) and its acoustic metamaterial were innovatively constructed using freeze casting–assisted extrusion printing process and building block–assembly strategy, featuring a micro–perforated panel (MPP) sound–absorbing structure. The PIHM with a density of 0.294g·cm−3 achieved a compressive strength of 10.2MPa because of its periodically distributed honeycomb topology. Moreover, the PIHM not only retained the lightweight and thermal insulation characteristics of aerogels but also exhibited excellent sound–absorption performance because of the dual dissipation of sound waves by the MPP structure and PI aerogel framework. By serially connecting PIHMs with different aerogel pore sizes and leveraging the distinct acoustic properties of the layered structure along with the significant increase in relative mass resistance and acoustic impedance, the acoustic metamaterial achieved absorption coefficient peaks of 0.82–0.91 at 622–726Hz, considerably widening the bandwidth with an absorption coefficient greater than 0.8. Finally, the composite sound–absorbing panel fabricated from a PIHM combined with common building materials demonstrated strong practicability and versatility. This research has pioneered a viable method for manufacturing PI aerogels with functional structures through 3D printing, expanding their application in the field of sound absorption and thermal insulation, and paving the way for the study of aerogel metamaterials in construction.

Robust, lightweight, thermally-insulating felt assembled by hollow and continuous yttria-stabilized ZrO2 fibers

Advanced hollow ceramic fiber materials with excellent thermal insulation and lightweight characteristics are urgently needed in rapidly developing areas such as aerospace. However, creating such hollow ceramic fiber materials has proven to be extremely challenging for current synthetic techniques. Here, we introduce a facile approach for the production of hollow yttria-stabilized zirconia (YSZ) fiber felts through sol–gel solution centrifugal spinning. It is found that the hollow structure can be effectively controlled by adjusting the mass ratios of inorganic salts and PVP, as well as the calcination temperatures. The resulting hollow YSZ felts exhibit low density (38 mg cm−3), robust tensile strength (439.56 ± 24.23 kPa), significant stretchability (>10 %), exceptional oxidation and high-temperature resistance, refractory properties, and outstanding thermal insulation characteristics (0.019 W/m K−1 at room temperature and 0.103 W/m K−1 at 1000℃). The successful synthesis of such fascinating materials may provide new insights into the design and development of hollow ceramic fibers.

Photocurrent in PZT/TiOx composite film prepared via self-assembly of perovskite matrix and ALD of titania

A novel approach for the preparation of ferroelectric composite films has been successfully developed by combining sol–gel evaporation-induced self-assembly (EISA) of porous lead zirconate titanate (PZT) films with atomic layer deposition (ALD) of titania. The EISA process, which utilizes a Brij-type surfactant, facilitates the formation of large columnar perovskite grains with narrow (∼20 nm) interconnected pores. ALD, employing the thermal reaction of titanium isopropoxide with water, ensures uniform titania growth within the pores throughout the film thickness, as demonstrated by transmission electron microscopy and ellipsometric porosimetry. The resulting PZT-TiOx composite films exhibit a pronounced photovoltaic current under visible light illumination, attributed to electron excitation from the valence band to Ti3+ states, followed by movement via a hopping conduction mechanism. The photocurrent value varies with the direction of polarization. This behavior presents a potential method for controlling photoconductivity through polarization, with possible applications in electronic and photonic devices.

Heater‐Embedded Visible‐Light Phototransistor Based on Cd‐Doped IGZO Film Fabricated through Microwave‐Assisted Sol–Gel Process

Heater‐Embedded Visible‐Light Phototransistor Based on Cd‐Doped IGZO Film Fabricated through Microwave‐Assisted Sol–Gel Process

Ga-doped ZnO nanoparticles for enhanced CO2 gas sensing applications

Gallium-doped zinc oxide (GZO) has demonstrated significant potential in gas-sensing applications due to its enhanced electrical and chemical properties. This study focuses on the synthesis, characterization, and gas-sensing performance of GZO nanoparticles (NPs), specifically targeting CO₂ detection, which is crucial for environmental monitoring and industrial safety. The GZO samples were synthesized using a sol–gel method, and their crystal structure was determined through X-ray diffraction (XRD), confirming the successful incorporation of gallium into the ZnO lattice. X-ray photoelectron spectroscopy (XPS) was employed to analyze the samples’ elemental composition and chemical state, revealing the presence of Ga in the ZnO matrix and providing insights into the doping effects. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy (EDS) was used to confirm the purity and elemental distribution of the synthesized samples, ensuring the homogeneity of the Ga doping. In-situ TEM measurements were also conducted on one of the three samples, with the smallest size. The experiment involved exposing the sample to argon (Ar) as a reference gas and carbon dioxide (CO₂) as the target gas to evaluate the sensor’s response under real-time conditions. The in-situ TEM provided nanoscale observation of changes in the crystal structure parameters, particularly the d-spacing, which exhibited significant alterations exceeding 3.2% when exposed to CO₂ and Ar gases. Furthermore, electron paramagnetic resonance (EPR) and optical joint density of states (OJDS) analyses were performed to examine the presence of paramagnetic defects and to comprehensively understand the electronic structure within the GZO sample, respectively.

High-Voltage NMC for LIBs via Ternary MOF-Lithium Carbonate System.

Systems for storing energy are essential for modern technology and daily life. Numerous investigations have been conducted, particularly on lithium-ion batteries. The development of the cathode active material is one of the areas of emphasis. On the NCM111 composition, which is widely utilized in lithium-ion batteries, there are development studies on doping, morphological modifications, and coating. In the presented work, a sol-gel process was utilized to manufacture ternary metal organic framework (MOF). MOFs, as a precursor, has many benefits for obtaining homogenous particles and lower thermal decomposition during process. However, lithium acetate or lithium hydroxide had been used for lithium source during sol-gel which are soluble in water. In contrast to the literature (e.g., using a cheap supply of lithium other than lithium hydroxide and acetate), lithium carbonate was used as lithium source in this study. Owing in part to the higher stability of lithium carbonate at lower temperatures, short-range ordered surface presence was seen during the high voltage cycling process. Nevertheless, the sample that produced with lithium carbonate (S6) exhibited stable cycling performance under high voltage conditions compared to the sample (R) produced with lithium acetate.

Effect of multivalent ion doping on magnetic, electrical, and dielectric properties of nickel ferrite nanoparticles

The nanoscale spinel structured ferrites co-doped with multi-valence ions are of great interest and proving to be promising for numerous applications. In light of this, herein we report tetravalent titanium ions (Ti4+) and divalent zinc ions (Zn2+) co-doped nickel ferrites with generic formula of NiFe2 − 2xTixZnxO4 (x = 0.00 ≤ x ≤ 0.20 in step of 0.05). The sol gel self combustion method in assistance with citric acid as fuel was employed to prepare the samples. The X-ray diffraction (XRD) analysis with Rietveld refinement was performed to confirm the single-phase cubic spinel structure. The sphere type grain morphology of the samples was revealed by SEM images. The compositional studies carried out by EDAX showed desired formation of the composition with absence of impurities in the samples. The characteristics bands belonging to the spinel ferrites were appeared in IR spectra confirming the successive sample forming. The different surface parameters including surface area and pore volume was estimated using Brunauer-Emmett-Teller (BET) analysis. The low coercive nature with soft magnetism was observed with the co-doping as revealed by M-H plots. The electric and dielectric parameters showed decrementing behaviour with increment in Ti4+-Zn2+ co-doping. This study outcome signifies that the Ti4+-Zn2+ co-doping in nickel ferrites could be a prominent for many nanoelectronics applications.