Influence Of Calcination Temperature Research Articles

Influence of Calcination Temperature on the NH3–SCR Performance of CeTiOx Catalysts Derived from Ce–Ti MOFs

Influence of Calcination Temperature on the NH₃–SCR Performance of CeTiO_<i>x</i> Catalysts Derived from Ce–Ti MOFs

Influence of Calcination Temperature on the Physicochemical Properties of Synthesized Hydroxyapatite from Cow Bone Waste

The chemical similarity found in hydroxyapatite (HA) with natural bone makes it a popular choice for bone replacement. Therefore, in recent years, there has been an increasing tendency towards manufacturing HA from biological sources or waste, such as animal bone waste. Using naturally derived HA can benefit the economy, the environment, and human health. Therefore, this paper reports on the extraction of HA from cow bone waste using a simple and cost-effective technique. The bone powder was calcined in a furnace at temperatures ranging from 700°C to 1000°C for two hours. Then, the synthesized HA was characterized using a Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD). FESEM images revealed that HA particles with non-uniform spherical morphology were produced where the size increases with the calcination temperature. This finding is consistent with the average value of particle diameter measured at a temperature of 1000°C (0.783±0.268 µm) which is much greater than at a temperature of 700°C (0.272±0.128 µm). EDX analysis revealed that the Ca/P ratio value obtained in this study indicates non-stoichiometric HA production. XRD analysis shows that only the HA phase is present and there is no secondary phase generated from the calcination process. Meanwhile, FTIR analysis can detect the main group elements of the HA which were OH- and PO43-. The findings obtained in this study prove the effectiveness of this method in producing highly crystalline HA powder from cow bone waste using the thermal treatment method.

Investigation the Influence of Calcination Temperature on Structural, Electrical and Gas Sensing Properties MnO&lt;sub&gt;2&lt;/sub&gt; Thick Films

Metal oxide nanoparticles are widely used in various fields, including catalysis, sensing, energy storage, and more. Manganese dioxide (MnO2) is a promising material for gas sensors due to its sensitivity to various gases, including oxidizing and reducing gases. The calcination temperature affects their size, crystallinity, surface area, and other properties. In the present research work, the influence of calcination temperature on the structural, electrical and gas sensing properties of MnO2 nanoparticles or nanopowders was investigated. The MnO2 nanopowder was calcinated at 200, 400, 600, and 800 °C in a muffle furnace for 4 hours. After that, using the calcinated powder of MnO2, the thick films were prepared using the standard screen printing technique. The structural characterizations were investigated using SEM, EDS, and XRD. It has been found that as the calcination temperature is increased, the electrical, structural, and gas-sensing properties of MnO2 change. The prepared thick films calcinated at 200, 400, 600, and 800 °C are labeled as samples 1, 2, 3, and 4, respectively, in this paper. It has been found that sample 4 shows maximum resistivity, a more specific surface area, a smaller crystallite, and a maximum gas response to H2S gas. The maximum sensitivity was found to be 76.32% to H2S gas at operating temperature 120 °C. The response and recovery time was also found quickly.

Influence of calcination temperature on the structural properties of hydrothermally synthesized LiMn1.5Ni0.5O4 cathode material: a comparative study for calculating crystallite size and lattice strain

Influence of calcination temperature on the structural properties of hydrothermally synthesized LiMn1.5Ni0.5O4 cathode material: a comparative study for calculating crystallite size and lattice strain

Optimization of Yb:CaF2 Transparent Ceramics by Air Pre-Sintering and Hot Isostatic Pressing

Yb:CaF2 transparent ceramics represent a promising laser gain medium for ultra-short lasers due to their characteristics: low phonon energy, relatively high thermal conductivity, negative thermo-optical coefficient, and low refractive index. Compared to single crystals, Yb:CaF2 ceramics offer superior mechanical properties, lower cost, and it is easier to obtain large-sized samples with proper shape and uniform Yb3+ doping at high concentrations. The combination of air pre-sintering and Hot Isostatic Pressing (HIP) emerges as a viable strategy for achieving high optical quality and fine-grained structure of ceramics at lower sintering temperatures. The properties of the powders used in ceramic fabrication critically influence both optical quality and laser performance of Yb:CaF2 ceramics. In this study, the 5 atomic percentage (at.%) Yb:CaF2 transparent ceramics were fabricated by air pre-sintering and hot isostatic pressing (HIP) using nano-powders synthesized through the co-precipitation method. The co-precipitated powders were optimized by studying air calcination temperature (from 350 to 550 °C). The influence of calcination temperature on the microstructure and laser performance of Yb:CaF2 ceramics was studied in detail. The 5 at.% Yb:CaF2 transparent ceramics air pre-sintered at 625 °C from powders air calcined at 400 °C and HIP post-treated at 600 °C exhibited the highest in-line transmittance of 91.5% at 1200 nm (3.0 mm thickness) and the best laser performance. Specifically, a maximum output power of 0.47 W with a maximum slope efficiency of 9.2% at 1029 nm under quasi-CW (QCW) pumping was measured.

Effective electromagnetic wave absorption strategy: Unlocking the potential of NiCo2O4 as an absorber

This study addresses a scientific challenge by elucidating the influence of calcination temperature on the properties and electromagnetic wave absorption capabilities of NiCo2O4, a material whose performance is inherently tied to its preparation process. Specifically, we systematically investigate how varying calcination temperatures not only diversify the material’s composition and morphology but also enhance its electromagnetic wave absorption properties. By controlling the calcination temperature, we not only achieve the successful synthesis of NiCo2O4 but also unravel intricate correlations among calcination conditions, material composition, and wave absorption performance. Notably, NiCo2O4 sample calcined at 400 °C exhibits remarkable electromagnetic wave absorption, marked by an exceptional maximum reflection loss of −53.93 dB and a broad absorption bandwidth spanning 6.24 GHz. These insights contribute to advancing the frontiers of NiCo2O4 utilization, particularly in the realm of electromagnetic wave absorption and beyond, underscoring the novelty and impact of our research.

Influence of calcination temperature on the 3D nanoscale topography of LaMnO3 thin films: A comprehensive surface analysis

In this paper, we present a comprehensive study on the 3D nanoscale topography of LaMnO3 thin films, focusing on the influence of calcination temperature on surface morphology. The study reveals significant structural, chemical, and morphological changes as a function of the calcination temperature. XRD analysis confirmed the formation of the orthorhombic LaMnO3 structure at 700 °C, 750 °C, and 800 °C, with increasing unit cell volume and crystallite size observed at higher temperatures. FTIR spectra identified characteristic functional groups associated with molecular vibrations, indicating the perovskite structure. SEM imaging showed grain growth with temperature, while EDS analysis confirmed compound formation and substrate interactions. AFM analysis revealed increased surface roughness with temperature, attributed to nucleation and crystal growth. Morphological and microtextural analyses further detailed changes in surface features, peaks, valleys, and voids. Fractal characterization highlighted variations in surface texture with temperature, with a decrease in dominant wavelength indicating changes in microtexture complexity. Overall, the findings provide insights into the temperature-dependent properties of LaMnO3 thin films, essential for optimizing growth conditions and understanding their potential applications in various fields.

Influence of calcination temperature and particle size distribution on the physical properties of SrFe12O19 and BaFe12O19 hexaferrite powders

The paper deals with the economic optimisation of ferrite powder preparation during producing hard ferrite magnets. The magnetic properties of ferrites are investigated by replacing feedstock and reducing calcination temperature and particles in the order of tens of microns. The granulates about 8–10 mm in size were calcined for 2 h in the temperature range from 1100 °C to 1300 °C and additionally crushed and milled to an average particle size of about 80–90 µm. The scanning electron microscopy images confirmed the agglomerates of particles with different shapes and sizes in tens of µm. The X-ray diffraction measurements revealed that, besides the SrFe12O19 and BaFe12O19 phases, there was also the presence of 2–39% hematite. The highest values of maximum energy product (BH)max = 930 J/m3 and remanent magnetic induction Br = 72.8 mT were obtained at a calcination temperature of 1300 °C. The Henkel plots confirmed the presence of exchange-coupling and dipolar magnetic interactions at lower and higher magnetic fields, respectively. The strength of interactions was also dependent on the calcination temperature. Replacing strontium with barium led to a deterioration of the magnetic parameters, which were optimal at a lower calcination temperature (1100 °C). This phenomenon was partly overcome by reducing the mean particle size of Ba-based hexaferrites to 45–50 µm.

Direct Epoxidation of Hexafluoropropene Using Molecular Oxygen over Cu-Impregnated HZSM-5 Zeolites

This study explores a novel method of directly epoxidizing hexafluoropropene with molecular oxygen under gaseous conditions using a Cu/HZSM-5 catalytic system (Cu/HZ). An in-depth investigation was conducted on the catalytic performance of Cu-based catalysts on various supports and Cu/HZ catalysts prepared under different conditions. Cu/HZ catalysts exhibited better catalytic performance than other porous medium-supported Cu catalysts for the epoxidation of hexafluoropropene by molecular oxygen. The highest propylene oxide yield of 35.6% was achieved over the Cu/HZ catalyst prepared under conditions of 350 °C with a Cu loading of 1 wt%. By applying characterization techniques including XRD, BET, NH3-TPD, and XPS to different catalyst samples, the relationship between the interaction of Cu2+ and HZSM-5 and the reactivity of the catalyst was studied, thereby elucidating the influence of calcination temperature and loading on the reactivity. Finally, we further proposed the possible mechanism of how isolated Cu2+ and acid sites improve catalytic performance.

Fabricating Spinel-Type High-Entropy Oxides of (Co, Fe, Mn, Ni, Cr)3O4 for Efficient Oxygen Evolution Reaction.

Fabricating efficient oxygen evolution reaction (OER) electrocatalysts is crucial for water electrocatalysis. Herein, the spinel-type high-entropy oxides of (Co, Fe, Mn, Ni, Cr)3O4 were synthesized through the high-temperature calcination approach. The influences of calcination temperatures on structures and electrochemical properties were investigated. The optimized catalyst of HEO-900 contains the hybrid structure of regular polyhedrons and irregular nanoparticles, which is beneficial for the exposure of electrochemically active sites. It was identified that the abundant high-valence metal species of Ni3+, Co3+, Fe3+, Mn4+, and Cr3+ are formed during the OER process, which is generally regarded as the electrochemically active sites for OER. Because of the synergistic effect of multi-metal active sites, the optimized HEO-900 catalyst indicates excellent OER activity, which needs the overpotential of 366 mV to reach the current density of 10 mA cm-2. Moreover, HEO-900 reveals the prominent durability of running for 24 h at the current density of 10 mA cm-2 without clear delay. Therefore, this work supplies a promising route for preparing high-performance multi-metal OER electrocatalysts for water electrocatalysis application.

Immobilization of 137Cs in NaY type zeolite matrices using various heat treatment methods

The accumulation of liquid radioactive waste presents a significant global challenge, necessitating effective strategies for safe management. This study investigates the immobilization of 137Cs radionuclides, a prominent component of liquid radioactive waste, in ceramic matrices based on 137Cs-saturated NaY Faujasite zeolite. Various thermal methods were employed, including cold pressing and sintering, cold pressing and sintering with microwave assistance, hot pressing, and spark plasma sintering, to enhance immobilization capabilities. Zeolite powder was saturated with 137Cs radionuclides using an adsorption technique with low-activity model liquid radioactive waste. In-situ XRD and dilatometry methods were used to study the thermal behavior during NaY Faujasite annealing. The influence of calcination temperature on lattice parameters and crystallite size was assessed. Immobilization effectiveness was evaluated through relative density, Vickers microhardness, compressive strength, and metal ion leaching kinetics. Mechanistic evaluation was performed using XRD and SEM-EDX studies. Results showed that spark plasma sintering exhibited the highest efficiency for immobilizing 137Cs radionuclides in NaY Faujasite matrices. This research contributes to liquid radioactive waste management by providing insights into the thermal behavior and enhanced immobilization capabilities of ceramic matrices.

Investigating the effects of calcination temperature on porous clay heterostructure characteristics

This study focuses on finding the optimal calcination temperature for synthesizing porous clay heterostructures (PCH). PCH was prepared using montmorillonite at different temperatures (200–800 °C) in a closed N2 environment. Samples were characterized via N2-physisorption, scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) to investigate the influence of calcination temperature. Characterizations show that the PCH composite exhibits an increasing surface profile observed by increasing specific surface area, changes in crystalline phases, porous surface, and varied particle size distribution. The position (degree and wavelength) and intensities of minerals and functional groups in PCH shift with temperature, as observed in both FTIR and XRD. This shows that variables such as heating rate, calcination temperature, and environment affect the structural changes in the clay material. In terms of active phase development, structural behavior, and material strength, the correct calcination temperature proved to be crucial.

A novel low-cobalt single-crystal lithium-rich manganese-based layered oxide cathodes with enhanced electrochemical performances

Single-crystal (SC) morphology of lithium-rich manganese-based layered oxides (LLOs) cathode materials, due to their stable structure and absence of excess grain boundaries, holds promise for addressing issues such as oxygen loss and poor cycle stability in traditional polycrystalline (PC) cathode materials. In this study, a low-cobalt SC LLOs cathode material with excellent electrochemical performances is successfully synthesized by the molten salt method and the appropriate calcination temperature. The SC LLOs cathode calcined at 900 °C exhibits superior physical properties. Its particle size of D50 is 332 nm, which results in an optimal average Li+ diffusion coefficient (DLi+) value of 10−10.29 cm2 s−1. At C/10 (1C = 250 mA g−1), it delivers the first discharge capacity of 242 mAh g−1 with an initial Coulombic efficiency (ICE) of 73.8 %. After 200 cycles at C/3, it maintains the capacity retention of 80.8 %. This work extensively elaborates on the influence of calcination temperature on the particle size, physical properties and electrochemical stability of low-cobalt SC LLOs cathode materials, which would provide effective guidance for the design of high-performance SC cathode materials.

Study on the Influence of Calcination Temperature of Iron Vitriol on the Coloration of Ancient Chinese Traditional Iron Red Overglaze Color.

Iron red, a traditional Jingdezhen overglaze color, is primarily colored with iron oxide (Fe2O3). In traditional processes, the main ingredient for the iron red overglaze color, raw iron red, is produced by calcining iron vitriol (FeSO4·7H2O). Analysis of ancient iron red porcelain samples indicates that the coloration is unstable, ranging from bright red to dark red and occasionally to black. Addressing this, the present study, from a ceramic technology standpoint, conducts a series of calcination experiments on industrial iron vitriol at varying temperatures. Utilizing methodologies such as differential scanning calorimetry-thermogravimetry (DSC-TG), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy with X-ray energy dispersive spectrometry (SEM-EDS), and optical microscopy (OM), this research scientifically explores the impact of iron vitriol's calcination temperature on the coloration of traditional Jingdezhen iron red overglaze color. The findings indicate that from room temperature to 550 °C, the dehydration of iron vitriol resulted in the formation of Fe2(SO4)3 and a minimal amount of α-Fe2O3, rendering the iron red overglaze color a yellowish-red shade. At 650 °C, the coexistence of Fe2(SO4)3 and α-Fe2O3 imparted a brick-red color to the iron red. As the temperature was elevated to 700 °C, the desulfurization of Fe2(SO4)3 produced α-Fe2O3, transitioning the iron red to an orange red. With further temperature increase to 750 °C, the particle size of α-Fe2O3 grew and the crystal reflectivity decreased, resulting in a purplish-red hue. Throughout this stage, the powder remained in a single α-Fe2O3 phase. Upon further heating to 800 °C, the crystallinity of α-Fe2O3 enhanced, giving the iron red overglaze color a dark red or even black appearance.

Synthesis of titanium dioxide nanoparticles for enhanced photocatalytic activity in the degradation of emerging contaminants

The study investigates the impact of calcination temperature and the addition of H2O2 on the properties of TiO2 synthesized through the sol–gel method. The photoactivity of TiO2 in degrading Paracetamol revealed that the optimal calcination temperature was identified as 350 °C, attributed to a smaller crystallite size, higher surface area, and the anatase phase. Adding H2O2 during TiO2 preparation influenced the porous structure and photoactivity. Transmission electron microscopy revealed nanoparticles with average sizes of 12 ± 3 nm. TiO2 prepared with H2O2 showed improved photoactivity, possibly due to surface modifications, removing 98 % of Paracetamol. The addition of scavengers influenced the degradation efficiency, confirming the involvement of reactive species such as hydroxyl radicals. In summary, the study provides valuable insights into the influence of calcination temperature and H2O2 addition on the properties and photoactivity of TiO2, emphasizing the importance of optimal synthesis conditions for enhanced performance in environmental remediation applications.

Study on the Role of Additives in Calcination Desulfurization Process of High Sulfur Petroleum Coke

Due to the high sulfur content of high sulfur petroleum coke, sulfur-containing gas will be produced in the production process, reducing product quality and other problems, resulting in increased production costs and equipment corrosion. How to reduce the sulfur content of high sulfur petroleum coke is of great significance to improve the utilization rate of high sulfur petroleum coke and the sustainable development of related industries. In this paper, the desulfurization of high sulfur petroleum coke was carried out by using the additive-assisted high-temperature calcination method. It was found that the desulfurization effect of different kinds of desulfurization additives was different, among which MO1, MC2, MC1 desulfurization effect was better, and the desulfurization rate could reach 68%, 58%, 56%. After compounding the three desulfurizers, the desulfurization rate can be up to 75%, and then the influence of calcination temperature and time on the desulfurization rate was investigated. Finally, the physicochemical properties of petroleum coke before and after desulfurization were analyzed by X RD, FT-IR.

Effect of calcination temperature on structure evolution of hematite nanoparticles

The objective of this study is to investigate the transition structure of iron oxide, specifically the change from magnetite to hematite, as well as the influence of calcination temperature on the structural growth of hematite nanoparticles. The magnetite was extracted from the native iron sand in Indonesia using the coprecipitation procedure. To generate hematite, magnetite was calcined at various temperatures (350, 500, 650, and 800 °C). The structural changes resulting from the effect of calcination temperature were investigated by combining a number of characterisation methods. The crystal structure was examined using synchrotron x-ray diffraction (SRD) and the local structure was examined using x-ray absorption spectroscopy (XAS). Crystallite size was calculated using the Debye-Schrerrer equation at the most dominant SRD peak. Surface morphology was investigated using scanning electron microscopy (SEM). SRD data revealed that the sample calcined at 350 °C displayed both the Fe3O4 and α-Fe2O3 phases, while higher temperatures revealed the single-phase α-Fe2O3. Furthermore, an increase in calcination temperature was shown to be associated with an increase in crystallinity and crystallite size. For the samples H350 and H800, the crystallinity increased from 95.56 to 98.17%. In the magnetite, H350, H500, H650, and H800 samples, the crystallite size increased from 9.57 to 29.55, 16.40, 28,48, 29.26, and 29.55 nm. Higher calcination temperatures, on the other hand, increase the interatomic distance while decreasing the Debye–Waller factor, according to XAS fitting data. It can be inferred that around 500 °C, the transition from Fe3O4 to single-phase α-Fe2O3 was observed. While a greater calcination temperature of at least 800 °C would alter the structural parameters, it would not affect the phase.

In vitro immersion study and characterization of biomimetic bovine hydroxyapatite scaffolds: Influence of calcination temperature (600 and 1000 °C) on apatite formation

This work reports on the properties of natural bovine hydroxyapatite (HAp) scaffolds calcined at temperatures of 600 and 1000 °C and on the effects of apatite formation on these calcined scaffolds during immersion experiments in Hank's Balanced Salt Solution (HBSS) from 0 to 28 days. The study systematically identifies different mechanisms that determine the formation of the apatite layer. First, compositional analysis of the scaffolds by inductively couple plasma (ICP) reveals significant differences in macromineral content, which includes calcium, phosphorus, magnesium, and sodium. Subsequent X-ray diffraction (XRD) analysis reveals the presence of hydroxyapatite in both scaffolds, while the 1000 °C sample has additional β-whitlockite due to the higher calcination temperature. Further investigation by Fourier Transform Infrared Spectroscopy (FTIR) and Raman analyzes revealed carbonated HAp in the 600 °C scaffolds and characteristic bands of HAp in the 1000 °C scaffolds. Morphological changes during immersion, documented by Scanning Electron Microscopy (SEM) images, display leaf-like and cauliflower-like structures in the 600 °C sample and rash-like features leading to leaf-type apatite formation in the 1000 °C sample. High-Resolution Transmission Electron Microscopy (HR-TEM) showed elongated crystals in both samples, confirming exclusive HAp presence in the 600 °C sample and the coexistence of HAp and β-whitlockite phases in the 1000 °C sample. After 28 days of immersion, TEM images at 600 °C reveal ordered apatite particles, while the 1000 °C images exhibit random apatite formation, confirmed by Energy Dispersive X-ray Spectroscopy in TEM (EDS-TEM). In addition, both scaffolds calcined at 600 and 1000 °C showed biocompatibility, as cytotoxicity tests confirmed a remarkable 100 % cell viability, underlining their non-toxicity. The scaffolds calcined at 600 and 1000 °C therefore exhibit high bioactivity and viability, supporting their suitability for bone tissue engineering applications.

Effect of calcination temperature on structural, morphological elastic and electrical properties of MgO nanoparticles synthesized by combustion method

This study explores the influence of calcination temperature on the properties of MgO nanoparticles (MgO NPs) synthesized via the solution combustion method. Through X-ray diffraction (XRD) and scanning electron microscopy (SEM), structural and morphological changes were investigated. Elastic and dielectric properties were analyzed using computational tools and impedance spectroscopy. Results show that the prepared nanomaterial is belongs to a cubic system and a space group of F m −3 m. Increasing in the calcination temperature (550 °C and 750 °C) enhances crystallinity, reduces defects, and improves structural uniformity. Elastic properties exhibit notable improvements, with Young's modulus increasing from 356.43 GPa for pristine MgO to 364.6 GPa for MgO calcined at 750 °C. Dielectric studies were conducted in the frequency range from 50 to 5 MHz at room temperature. Dielectric analysis reveals enhanced properties, including increased dielectric constant and AC conductivity with rising temperature. The study emphasizes the pivotal role of calcination temperature in tailoring MgO NPs for diverse applications.

Surface functionalized visible light-responsive yttrium orthovanadate for photocatalytic hydrogen production

Yttrium orthovanadate (YVO4), a wide-bandgap photocatalyst was tuned into a visible responsive material by anchoring an organic framework on the surface of YVO4 nanoparticles using polyethyleneimine (PEI). The surface organic framework was identified as the decomposed PEI derivatives with the carbonyl and carboxylic acid functional groups by the FTIR and XPS analyses. The top of the valence band (VB) was raised and the bottom of the conduction band was moved down; hence, the band gap of YVO4 was reduced to absorb the light in the visible region for all three synthesized samples, which was confirmed by DRS UV–Vis analysis. The functional groups facilitated more water molecules on the YVO4 surface via hydrogen bonding; hence, the YVO4 surface acquired superhydrophilicity. Among the three YI, YII, and YIII samples synthesized with three different calcination temperatures of 80, 260 and 400 °C respectively, YII showed many advantageous photocatalytic properties. The optimum loading of organic compounds obtained on YII surface at 260 °C, which improved the surface area, visible light absorption, hydrophilicity, and exciton's life. Hence, YII showed a better performance of 3.75 mmol h−1g−1cat H2 production than YI and YII. This work interestingly revealed the influence of calcination temperature on surface functionalization and the performance of catalytic materials.