Solution Combustion Synthesis Research Articles

Mesoporous TiO2 and Fe-containing TiO2 prepared by solution combustion synthesis as catalysts for the photodegradation of paracetamol.

Water pollution due to emerging contaminants, e.g., pharmaceuticals, is one of the most frequently discussed issues. Among them, paracetamol received great attention due to its physico-chemical properties, persistence, and adverse environmental effects. Different techniques were employed for its degradation and, among them, photodegradation is considered one of the most suitable to pursue the aim. This work aimed to synthesize mesoporous TiO2, even with the presence of iron, through a one-pot method, with an enhanced ability to abate paracetamol. Precisely, pure and iron-containing (3.5 wt%) TiO2 were successfully obtained employing an uncommon procedure for this kind of material, mainly solution combustion synthesis (SCS). Moreover, a traditional hydrothermal method and a commercial Degussa P25 were also investigated for comparison purposes. The samples were characterized through N2-physisorption at - 196°C, XRD, XPS, EDX,DR UV-Vis, and FESEM analysis. The catalytic activity was investigated for the abatement of 10ppm of paracetamol, under UV irradiation in acidic conditions (pH = 3) and in the presence of H2O2. As a whole, the best-performing catalysts were those obtained through the SCS procedure, highlighting a complete removal of the organic pollutant after 1h in the case of Fe/TiO2_SCS, thanks to its highly defective structure and the presence of metal Fe. To better investigate the performance of both pure and Fe-containing SCS samples, further oxidation tests were performed at pH = 7 and in the absence of H2O2. Noteworthy, in these conditions, the two samples exhibited different behaviors, highlighting different mechanisms depending on the presence or absence of iron in the structure. Finally, a kinetic study was conducted, demonstrating that a first order is suitable for its abatement.

Structural, morphological, and magnetic features of granular TbFeO3 perovskite synthesized via direct solution combustion synthesis

Structural, morphological, and magnetic features of granular TbFeO3 perovskite synthesized via direct solution combustion synthesis

A novel aloe vera mediated Bismuth–Magnesium–Copper nanocomposite for radiation shielding applications

In the current study, Bismuth-Magnesium-Copper nanocomposites (BMC NCs) are synthesized using versatile solution combustion synthesis using Alovera extract as a reducing agent. As obtained BMC NCs are characterized using standard techniques. Bragg’s reflections confirmed the formation of multi-phase BMC NCs with crystal sizes 18.11 nm and 21.12 nm. The surface morphology of BMC NCs confirmed the agglomeration of spherical-shaped nanoparticles. EDAX spectrum analyzed the presence of Bi, Mg, and Cu. The direct energy gap is found to be 3.08 eV. X-ray/gamma radiation shielding properties are then evaluated using a NaI(Tl) detector coupled with MCA. Shielding parameters are slightly higher than lead. Neutron shielding parameters are compared with conventional shielding materials. Scattering length is found to be 8.8 fm, and neutron absorption cross-section and neutron attenuation parameters of BMC NCs are found to be efficient when compared with lead, concrete, and steel. Bremsstrahlung radiation shielding parameters are computed at 1.511 MeV. Bremsstrahlung efficiency is comparable to lead, bremsstrahlung dose rate and specific bremsstrahlung constant are found to be more in comparison with lead. Thus, BMC NCs are highly efficient in shielding X/gamma ray and neutron radiations.

Investigation of electrochemical and photoluminescence properties of Dy[formula omitted] doped SrO/BaO/Al2O3 nanocomposite for supercapacitor and display applications

The current study investigates the synthesis and characterization of dysprosium-doped strontium barium aluminum nanocomposites (SBAD NCs), aiming to enhance their suitability for display and supercapacitor applications. SBAD NCs are synthesized by Solution combustion synthesis using aloevera extract as a reducing agent. Multi-phase formation of NCs due to SrO, BaO, and γ-Al2O3 phases was confirmed by PXRD analysis, and crystallite size is found to be in the range of 26 nm to 36 nm. SEM analysis confirmed the surface morphology and the elemental composition was affirmed by the EDAX spectrum which confirmed the purity of the synthesis. The blue shift in the UV–visible absorption peak with increasing dopant concentration suggests a rise in the direct energy band gap from 4.07 eV to 4.11 eV. FTIR analysis confirmed functional groups and fingerprint region affirmed the presence of SrO, BaO, and AlO bonds. Photoluminescence analysis performed under excitation wavelength 276 nm revealed a prominent emission peak at 565 nm, and the CIE values fall in the yellow-green region of visible spectra. The CCT value was found to be 4490 K–4542 K which might find an application as a nanophosphor in cool light-emitting diodes. The tailored nanocomposites exhibit exceptional electrochemical performance characterized by superior specific capacitance, and improved charge–discharge kinetics, as evaluated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance is found to be in the range of 103.26 F/g to 173.24 F/g at a scan rate of 10 mV/s with increasing Dy3+ dopant concentration from 1 mol% to 9 mol% respectively. The dysprosium-doped SBAD NCs emerge as promising candidates for high-performance energy storage systems and vibrant display technologies, offering a synergistic integration of efficient energy storage and vivid display functionalities.

Fabrication, sintering behavior, and strength of tritium breeding ceramic pebbles with Pb addition

Lithium ceramics are regarded as potential candidates for tritium breeding in fusion reactors. Lead (Pb) was added to the ceramic to improve the strength and tritium release properties. The Li2TiO3-0.5Li4SiO4–Pb ceramic powders with the Pb contents of 5 wt% and 20 wt% were prepared by microwave-induced solution combustion synthesis. It was confirmed that the Pb was in the form of the Li2PbO3 phase in the powders. The Li2TiO3, Li4SiO4, and Li2PbO3 crystallites were composited at nanoscale level, which was confirmed by the transmission electron microscopy (TEM). During high-temperature sintering, the Li2PbO3 was transformed into PbO, which facilitated the densification process at low temperatures. The chemical state in the sintered body was characterized by X-ray photoelectron spectroscopy (XPS) with 3 keV Ar+ sputtering. The binding energies for Pb were 137.2 and 142.2 eV. There was almost no change in peak position during Ar+ sputtering, showing that Pb was firmly adherent with oxygen atoms. Besides, the as-synthesized powders were used for the pebble fabrication. The average crush load of Li2TiO3-0.5Li4SiO4–20%Pb pebbles sintered at 1223 K was 124 N, which was much higher than that without Pb addition. It was proved that the crush load increased almost linearly with the increase in the size of the pebbles. Thus, the bending strength of the sintered ceramic body was used to evaluate the mechanical properties. Further, the grain growth kinetics was studied. It was confirmed that the Pb addition reduced the activation energy of grain growth, which realized the densification of the ceramic pebbles at low temperatures.

Synthesis of Li doped MgFe2O4 nanoparticles for humidity sensor applications

Recently, there has been a greater emphasis on researching the potential use of ferrite nanoparticles as humidity-sensing materials. We report on the humidity-sensing properties of Mg1-yLiyFe2O4 (y = 0, 0.01, 0.03 and 0.05), which were synthesized using the solution combustion synthesis route. According to the XRD analysis, it was observed that both the unit cell volume and the crystallite size increased as the concentration of lithium-ion increased. The crystallite size was measured to be 17-22 nm, indicating the presence of nanomaterials. Moreover, the material exhibited a single phase with the Fd-3m space group, suggesting its structural integrity and uniformity. The FE-SEM images revealed that the porous nature of the material became more pronounced with higher concentrations of Li, indicating potential benefits for sensing applications. The synthesized powder demonstrated promising characteristics for use in humidity sensors. Specifically, it was noted that increasing the Li composition led to a notable increase in resistance, particularly significant for the Li = 0.05 concentration, which exhibited the highest average sensitivity. This suggests that Li doping at this concentration effectively enhances resistance, a crucial aspect for sensor functionality. The response and recovery times of thin film humidity sensors fabricated from these materials were determined to be 9 and 12 seconds, respectively. These times indicate rapid and efficient sensing capabilities, essential for real-time monitoring applications. Moreover, the newly discovered sensing material exhibited exceptional stability and reproducibility, further highlighting its potential for practical sensor applications. In summary, the synthesized materials show great promise for humidity sensor applications due to their enhanced sensitivity, rapid response and recovery times, as well as their stability and reproducibility. These findings open up avenues for the development of advanced sensing technologies with improved performance and reliability.

Oxide/metal interface enhancement for improved dispersion strengthening mechanism in oxide-strengthened tungsten

The addition of secondary ceramic particles has shown to be effective in enhancing the mechanical properties of tungsten alloys. The diverse strengthening effects observed with various secondary particles necessitate further investigation. Herein, three ultrafine-grained, oxide-dispersed-strengthened tungsten alloys were prepared using solution combustion synthesis combined with low-temperature sintering. We thoroughly investigated the influence of Al2O3, La2O3, and Y2O3 on the microstructure and mechanical properties of tungsten, as well as their respective strengthening mechanisms. A detailed comparison revealed discrepancies between the yield strength experimentally measured and the theoretically predicted strength based on conventional grain refinement strengthening and dispersion strengthening theories, highlighting the significance of the intrinsic nature of dispersed oxides. Electron microscopy analysis and density functional theory calculations revealed that, compared to other oxides, the heterogeneous interface of Al2O3 with W exhibited minimal lattice distortion and the highest work of separation, resulting in a robust interface bonding. The prepared W–Al2O3 alloy showed exceptional performance with Vickers hardness HV0.2 of 698.9 and yield strength of 2488 MPa. Its yield strength surpassed that of W–Y2O3 and W–La2O3 alloys, as well as other commonly reported refractory metal materials.

Dry Reforming of Methane over Mn-modified Ni-based Catalysts

AbstractNi-based bi- and trimetallic Mn, Mg and aluminum containing catalysts prepared by the solution combustion synthesis (SCS) method were tested in dry reforming of methane (DRM). As a comparison 12 wt.% Ni/α-Al2O3 catalyst prepared by wet impregnation was also investigated. The catalysts were characterized by means of XRD, N2 physisorption, H2-TPR, CO2-TPD, NH3-TPD, TPO, CHNS, TGA, SEM and TEM. Formation of crystalline MnAl2O4 was observed at high temperatures during SCS. The average nickel particle size varied in the range of 12–36 nm. Addition of Mn promoted reduction of Ni and elevated the amount and strength of the basic sites. Graphical Abstract

Solution Combustion Synthesis of New Composites Based on Iron Oxide and Mango Waste for Heterogeneous Photocatalysis with UV and Solar Radiation

Solution Combustion Synthesis of New Composites Based on Iron Oxide and Mango Waste for Heterogeneous Photocatalysis with UV and Solar Radiation

Solution combustion synthesis of zinc and calcium aluminate spinel phase materials: optical and structural properties

Solution combustion synthesis of zinc and calcium aluminate spinel phase materials: optical and structural properties

Microstructure and thermoelectric properties of porous CaMnO3/CaMn2O4 composite prepared by spray solution combustion synthesis

Oxides are attractive and promising compounds for application as thermoelectric materials owing to thermal and chemical stability, cost-effectiveness, and environmental safety. In this work, CaMnO3 perovskite hollow spheres were synthesized by spray solution combustion synthesis. The effect of the fuel glycine on the phase composition, morphology, and microstructure of CaMnO3 was studied, and the influence of synthesis parameters on the characteristics of the sintered materials was investigated. The porous CaMnO3 (porosity 10–20%) forms by pressureless sintering at 1473 K, which is accompanied by the precipitation of marokite CaMn2O4. It is possible to alter the porosity level as well as marokite and pore size in the CaMnO3/CaMn2O4 composite by tailoring the fuel amount, which, in turn, affects the thermoelectric properties. The zT value of 0.13 at 1073 K, to the best of our knowledge, is the highest zT reported for the undoped CaMnO3 material.

Plasma‐catalytic CO2 methanation over NiO/bentonite catalysts prepared by solution combustion synthesis

AbstractA solution combustion synthesis (SCS) process to prepare nickel catalyst over bentonite (NiO/Ben) is reported. Compared to the traditional impregnation method, NiO/ben produced by SCS has smaller nickel particle size and higher dispersion. With a metal loading of 20 wt%, the afforded NiO/Ben demonstrates excellent catalytic activity for CO2 methanation in a dielectric barrier discharge reactor. In certain discharge conditions (H2:CO2 ratio of 5 in feed gas, discharge input power of 45 W, and gas hourly space velocity of 11 320 h−1), CO2 conversion and CH4 selectivity are as high as 55.8% and 84.6%, respectively. Under the conditions of plasma configuration, the strong interaction between the nickel species and the support plays an important role in the CO2 methanation process.

Effect of Ni/SiO2 catalyst preparation method on methane decomposition and CO2 gasification cycles

Catalytic methane decomposition is a promising reaction to produce CO2-free hydrogen from methane-rich feedstock with solid carbon as a by-product. Significant research conducted on this reaction to find ways to manage and utilize this solid carbon. In this work, the methane decomposition reaction is followed by Reverse Boudouard Reaction using CO2 feedstock to convert the solid carbon to carbon monoxide, which is a valuable starting component for many chemical applications. Realizing this promising concept would require a catalyst that is efficient for both reactions. Herein, we explored the potential of using solution combustion synthesis (SCS) to make a 5 wt% of Ni supported SiO2 catalyst and benchmarked it versus the conventional impregnation method. The catalyst prepared by SCS showed an improved performance at different temperatures, space velocities, and catalyst pellet sizes. The SCS catalyst successfully completed five repeated cycles reaching up to 38.1 h of stable time on stream operation, whereas the impregnated catalyst was not able to complete the second testing cycle with only 14 h of time on stream operation. A thorough characterization using XRD, H2 and O2 TPR, TEM, SEM, XPS, and Raman spectroscopy were conducted to provide an adequate explanation for the observed performances for both catalysts. The Ni nanoparticles size and distribution, the strength of the metal support interaction, and the nature of graphitic carbon were the key factors affecting the catalytic performance. Insights on how to make an optimal catalyst for this promising process is identified which is a step forward toward making separated H2 and CO streams from methane feedstock and CO2, respectively.

Improving the electrochemical performance of LiNi0.5Mn1.5O4 by ZnO nanocrystals coating

The cathodic material LiNi0.5Mn1.5O4 was produced by the Solution Combustion Synthesis method (SCS). The as-made crystalline nanoparticles were annealed at 900 °C, obtaining micron-sized particles, and then coated with ZnO nanocrystals at a weight relation between 0.5 and 2.5 wt%, also using the SCS method. The nanocrystalline porous coating was confirmed by XRD, SEM and TEM. Electrochemical measurements verified that all materials coated with ZnO nanoparticles improved their electrochemical properties concerning the uncoated material, preventing degradation over the cycles, and stability along cyclic voltammetry cycles. It was observed that a 1 wt% ZnO coating presents the best improvement in discharge capacity and rate capability, and that the charge transfer resistance of the coated material is reduced to 1/3 of the uncoated one after 100 electrochemical cycles. In this work, the simple, time and energy saving SCS method was verified to obtain nanoshell-coated LNMO microparticles with improved electrochemical performance.

Synthesis of lithium doped magnesium ferrites and their vibrational and magnetic properties: Correlation of experimental and density functional theory

Recently, there has been an increased focus on investigating the possible use of ferrite nanoparticles as magnetic memory devices. In this study, we report on the structural, microstructural, Raman, density functional theory and magnetic characteristics of Mg1-xLixFe2O4 (x = 0, 0.15, 0.3, 0.45, 0.5 and 0.75). Samples were synthesized by solution combustion synthesis method. Samples were subjected to characterize X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Raman Spectra. XRD reveals that all synthesized samples show a single phase formation and unit cell volume, crystallite size varied with an increase in Lithium-ion concentration. SEM micrographs confirmed the porous nature increases with the rise of Li concentration. Particles are agglomeration and spherical type of nature was confirmed by TEM images. Further, Raman Spectra confirms the spinel cubic structure of MgFe2O4 nanoparticles belongs to the Fd3m space group. Despite the fact that the full unit cell has 56 atoms (Z = 8), the smallest Bravais cell consists of only 14 atoms (Z = 2). Consequently, in order to understand this effect, the electronic structure of pure and doped models was investigated through the Band Structure and Density of States (D.O.S.) profiles. First the crystalline structure of pure and Li-doped MgFe2O4 was analyzed based on the optimized lattice parameters and M − O (M = Mg, Li and Fe) bond distances. The band-gap was computed to be 2.54 eV being a direct transition between two points, in an excellent agreement with the experimental measurements. To investigate the temperature dependent magnetic properties, the M − H loops of Li doped MgFe2O4 nanoparticles traced at below and above room temperature over the applied magnetic field ±60 kOe. The M − H loops recorded at above and below room temperature demonstrated that the ferromagnetic nature of the sample. Further, the magnetic properties was investigated using temperature dependent FC and ZFC magnetization measurements. Above room temperature, the ZFC and FC curves show irreversibility and split at certain temperatures, as well as a broad maximum in ZFC curves at blocking temperature (TB). Saturation magnetization (Ms) values are higher at 15 K compared to 300 K, attributed to reduced thermal fluctuation. Our results suggest that synthesized materials are useful for room temperature magnetic memory device application.

Sr0.99Zr(PO4)2:0.01Eu3+ ceramic glass for photoluminescence applications

This paper reports the first-time synthesis of Sr0.99Zr(PO4)2:0.01Eu3+ nanophosphor via solution combustion method using glycine as fuel at a fuel-to-oxidizer ratio of 1:1. The PXRD pattern confirmed the formation of the desired phase, while the Scherrer calculation revealed an average particle size of approximately 60 nm. Scanning electron microscopy (SEM) further corroborated the particle size, estimating it around 75 nm. The material exhibited a characteristic mesoporous structure, a hallmark of the solution combustion synthesis technique. Photoluminescence (PL) spectroscopy revealed two intense emission peaks at 590 nm and 615 nm, attributed to Eu3+ ions, suggesting potential applications in LED technology. CIE coordinates indicated emission close to the white region defined by the NTSC standard

Low-temperature synthesis of transparent conducting La-doped BaSnO3via rejuvenation of the dried peroxo-precursor

In this article, we develop a low-temperature route for the synthesis of the high figure-of-merit transparent conductor, La-doped BaSnO3. Towards this, we first study the evolution of the cubic perovskite phase of the undoped BaSnO3 during solution combustion synthesis. A peroxo/superoxo precursor synthesized via H2O2 assisted co-precipitation is employed as the oxidizing agent. Typically, precursor drying is detrimental to the low-temperature conversion of the precursor to crystalline BaSnO3. The synthesis procedure developed herein is agnostic to the altered precursor composition obtained under the particular drying conditions. This is achieved by re-solvation of the precursor with ethyl alcohol prior to the annealing. The added ethanol plays the role of fuel, enabling an exothermic reaction of the components of the mixture, providing the heat of reaction for conversion and crystal growth. Complete conversion of the precursor to phase-pure BaSnO3 with a three-fold increase in the crystallite size at lower temperatures is thus achieved. We then demonstrate the facile incorporation of lanthanum as a dopant through this method. The low-temperature synthesized lanthanum substituted BaSnO3 displays optical absorption in the NIR region corresponding to free carrier generation, and n-type conductivity.

Solution Combustion Synthesis of Ce‐based Composite Oxygen Carriers for Chemical Looping Reforming of Methane

Efficient activation and the conversion of methane to value‐added products have long attracted interest. Chemical looping reforming has become a competitive technology to transform methane into syngas that can act as raw material for various chemicals. In this paper, the methane chemical looping reforming reactivity of the Ce‐Co composite oxygen carriers fabricated with different preparation methods, including solution combustion, ball‐milling, hydrothermal, and co‐precipitation method, are investigated on a fixed‐bed. Various bulk/surface characterizations (TEM, XRD, BET, XPS, Raman, etc.) were applied to reveal the effect of preparation methods on the properties of these oxygen carriers. The results indicate that the oxygen carrier prepared by the solution combustion method exhibits excellent methane conversion, high syngas yield, and desirable H2/CO ratio, as well as stable regenerability because of its relatively small crystal size, large specific surface area, high oxygen vacancy concentration and Ce3+/Ce4+ ratio. This work may be helpful in the preparation of highly active and stable oxygen carriers for chemical looping reforming reaction of methane.

Anti-oncogenic Potential and Inflammation Modulatory Response of Green Synthesized Biocompatible Silver Nanoparticles.

This study presents a novel approach to synthesizing silver nanoparticles (Ag NPs) using a solution combustion synthesis (SCS) method with Catharanthus roseus (C. roseus) leaf extract. The NPs were thoroughly characterized through X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Transmission electron microscopy (TEM), and Selected area electron diffraction (SAED), elucidating their crystal structure. Notably, the synthesized Ag NPs exhibited a significant dose-dependent decline in viability of the MDA-MB 231 breast cancer cell line, with an IC50 value of 13.3 μg/mL, underscoring their potential as potent anticancer agent. Beyond cytotoxicity, the study pioneers an investigation into the biocompatibility of Ag NPs by blood hemolsysis, providing critical insights into their safety and biomedical applicability. Furthermore, this research uncovers a distinctive facet of Ag NPs, revealing their inhibitory effects on the inflammatory enzyme secretory phospholipase A2 (sPLA2), a recognized biomarker for breast cancer. The demonstrated in vitro and in vivo inhibition of sPLA2 highlights the multifaceted potential of Ag NPs in not only targeting cancer cells but also modulating inflammatory responses associated with breast cancer, positioning the study at the forefront of advancements in nanomedicine and cancer therapeutics.

Solution combustion synthesis of Bi2Fe4O9 possessing enhanced magnetic and photocatalytic properties

Bismuth ferrites have attracted much attention in recent years because of the possibility of their promising practical applications in sensing systems as well as digital memory.In this study, nanocrystalline material based on bismuth ferrite with mullite-like structure was synthesized by solution combustion technique. The results of XRD confirmed the formation of a Bi2Fe4O9 orthorhombic phase with an average crystallite size 60 ± 3 nm. The composition, morphology and porosity were characterized by SEM/EDX and helium pycnometry. The peculiarities of the material formation from the initial mixture with a glycine deficiency by subsequent calcination of the combustion product in air, were characterized by XRD, EDX and simultaneous thermal analysis.Magnetic properties of the substance were studied by Mössbauer spectroscopy and magnetometry which showed that its magnetization is enhanced in comparing to similar materials by several times. Specific features in the Bi2Fe4O9 magnetization with changing temperature were analyzed for the first time.The photocatalytic activity of Bi2Fe4O9 during the decay of rhodamine B has been studied. It is demonstrated that the degradation of rhodamine B increased by about 70% when irradiated with visible light.