Effect Of Calcination Temperature Research Articles

Synthesis of rice husk–based–mesoporous silica nanoparticles by facile calcination

Abstract The growing industrial demand for mesoporous silica nanoparticles (MSNs) necessitates the exploration of alternative raw materials due to the limited availability of traditional sources. Rice husk, an environmentally sustainable by-product, offers a cost-effective solution with reduced environmental impact. This study investigates the synthesis of MSNs from rice husk using the sol-gel method, focusing on the effect of calcination temperature on their physical and chemical properties. Characterization confirmed the successful synthesis of MSNs. Fourier transform infrared spectroscopy identified siloxane groups in all samples, indicating silicate materials. Scanning electron microscopy-energy dispersive spectroscopy revealed a spherical-like morphology with silica as the primary component. Transmission electron microscopy measured the average particle sizes of control, 400°C calcined, and 600°C calcined MSNs as 50.5 nm, 49.3 nm, and 53.1 nm, respectively. X-ray diffraction analysis indicated the presence of silica phases in all samples. Surface area analysis showed a significant decrease in surface area (653 m²/g to 113 m²/g) and pore volume (0.9 cm³/g to 0.1 cm³/g) with increasing calcination temperature, while pore size slightly increased from 2.6 nm to 2.7 nm. Calcination temperature influences the removal of CTAB surfactants, enhances silicate bond strength, and increases silicon purity, resulting in reduced surface area and pore volume without altering the basic morphology or crystal structure of the MSNs. The synthesized MSNs, with their large surface area and unique properties, demonstrate potential for diverse applications, including their use as nanocontainers for corrosion inhibitors

Effect of Calcination Temperature on the Transformation of Spent NCM811 into Efficient TMO Electrocatalysts

Abstract The expansion of electric vehicles has increased spent lithium-ion batteries (LIBs) containing valuable transition metals. Recycling these materials reduces economic costs and addresses resource shortages. Additionally, transition metal-based catalysts derived from spent LIBs can replace expensive noble metal catalysts. This study examines the catalytic performance of spent LiNi0.8Co0.1Mn0.1O2 (NCM811) materials, enhanced by adjusting mixed valence states and defect structures. Increasing calcination temperature transformed the layered structure into spinel and rock salt phases, inducing mixed valence states. Consequently, the optimized NCM catalysts exhibited improved catalytic activity in both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The ORR onset potential increased by 0.07 V, while the OER overpotential decreased by about 26.9%. In a zinc-air battery, the optimized catalyst demonstrated a discharge capacity of 792.1 mAh g⁻1 and stable performance over 100 cycles. Operando X-ray absorption spectroscopy (XAS) confirmed Mn as the main active site, with Ni and Co enhancing Mn's activity as electron donors and acceptors. These findings suggest that calcination-induced structural changes and mixed valence states enhance Mn site reactivity, improving catalytic performance. Overall, this study highlights the feasibility of repurposing spent LIB cathode materials into efficient electrocatalysts, thereby improving the economic viability and sustainability of catalyst development.

Calcination Temperature Effects on Ni/ZrO2 Catalysts for Dry Reforming of Methane

In this study, calcination temperatures (550, 650, and 750 °C) are utilized to analyze theefficiency of Ni-based catalyst for dry reforming of methane (DRM), a potential technique forreduction in greenhouse gases and synthesis of syngas. Ni catalysts were obtained from theimpregnation of 10 wt.% Ni onto ZrO2 prepared in the laboratory. A study of the synthesizedcatalysts was carried out using characterization techniques such as N2 physisorption, XRD,FTIR, and SEM. This analysis showed that calcination temperature affects the catalytic activityof the material investigated in the study. For those catalysts showing initially fairly highconversion of methane (more than 50 %), an increase in calcination temperature resulted in alower conversion of methane. It is believed that Ni nanoparticles sinter at higher temperatures resulting in decreased active surface area of the catalyst which in turn minimizes the number of active sites for the DRM reaction. On the other hand, for the catalysts with lower initial activity below 40 %, the effect of calcination temperature to the catalyst activity was not highly significant. This could be because the Ni particles in these catalysts are larger, or else the metalsupport bonds are not so strong that the catalysts cannot resist sintering at high temperatures. From the tested catalysts, NZS-10 has shown the highest performance with the average conversion of CH4 and CO2 at 60.5% and 62% respectively, and the lowest deactivation rate of 5%. This superior performance can be attributed to a combination of factors, including high surface area, optimal Ni particle size, strong metal-support interactions, resistance to sintering, and a well-developed porous structure. Fine-tuning certain characteristics of the NZS-10 catalyst can make the catalyst more efficient and have longer stability.

Photocatalysis by Mixed Oxides Containing Niobium, Vanadium, Silica, or Tin

Nb-Sn, V-Sn mixed-metal oxides and Nb-Si, V-Si metal oxide–silicas were successfully synthesized through a “soft” templating method, in which appropriate amounts of metal salts (either niobium(V) chloride, or vanadium(IV) oxide sulfate hydrate or tin(II) chloride dihydrate) or tetraethyl orthosilicate (TEOS) were mixed with hexadecyltrimethylammonium chloride (HDTA) or sodium dodecyl sulfate (SDS) solutions to obtain a new series of mesoporous oxides, followed by calcination at different temperatures. As-obtained samples were characterized by SEM, TEM, XRD, and UV-Vis spectra techniques. The photocatalytic activities of the samples were evaluated by degradation of methyl orange II (MO) under simulated sunlight irradiation. The effects of metal species and calcination temperature on the physicochemical characteristic and photocatalytic activity of the samples were investigated in detail. The results indicated that, compared to pure oxides, mixed-metal oxide showed superior photocatalytic performance for the degradation of MO. A maximum photocatalytic discoloration rate of 97.3% (with MO initial concentration of 0.6·10−4 mol/dm3) was achieved in 300 min with the NbSiOx material, which was much higher than that of Degussa P25 under the same conditions. Additionally, the samples were tested in the photochemical oxidation process, i.e., advanced oxidation processes (AOPs) to treat the commercial non-ionic surfactant: propylene oxide ethylene oxide polymer mono(nonylphenyl) ether (N8P7, PCC Rokita). A maximum of 99.9% photochemical degradation was achieved in 30 min with the NbSiOx material.

Formulating Single Phasic Silicorhenanite (α- and β-Na2Ca4(PO4)2SiO4) Bioactive Glass Materials Competing with Commercial Crystalline Hydroxyapatite Bone Mineral for Biomedical Applications.

Hydroxyapatite (HAP) is a well-known medically renowned bioactive material known for its excellent biocompatibility and mechanical stability, but it lacks fast bioactivity. The restricted release of ions from hydroxyapatite encourages the search for a faster bioactive material that could replicate other properties of HAP. A new sol-gel-mediated potentially bioactive glass material that could mimic the structure of HAP but can surpass the performance of HAP bioactively has been formulated in this study. Lefebvre et al. suggested that the silicorhenanite phase with the formula Na2Ca4(PO4)2SiO4 is isostructural to hydroxyapatite; however, data in support of this hypothesis are scant. This study succeeds in developing fast apatite-growth-inducing bioactive glass particles similar to the structure of hydroxyapatite. Also, for the first time, the existence and evolution of two forms of silicorhenanite (α- and β-Na2Ca4(PO4)2SiO4) have been unraveled, and their properties have been explored. The effect of calcination temperature on the phase formation of the biomaterial is notified by looking into the result that heat treatment to 900 °C resulted in α-Na2Ca4(PO4)2SiO4 (Sili 900) and 1000 °C yielded β-Na2Ca4(PO4)2SiO4 (Sili 1000). This study conveys a new finding that the hydroxyapatite is isostructural to β-Na2Ca4(PO4)2SiO4 but not to α-Na2Ca4(PO4)2SiO4. Raman spectroscopic analysis proved this structural similarity of Sili 1000 and c-HAP, with relative spectra possessing phosphate bands and the irrelevance of Sili 900 to Sili 1000 and c-HAP. The in vitro MTT assay using NIH 3T3 fibroblasts and in vivo wound healing study confirm the enhanced bioactivity and compatibility of Sili 900 and Sili 1000 compared to c-HAP, favored by the presence of a silica matrix and semicrystallinity. pH analysis proved the rapid ionic leaching out from Sili 900 and Sili 1000 and the faster reactivity of Sili 1000 with the fluid. This rapid burst of ions enhances the clotting ability of the Sili 1000 bioactive material and can be a good ibuprofen drug carrier, which is a potential challenger to hydroxyapatite.

THE EFFECT OF CALCINATION TEMPERATURE AND HOLDING TIME ON STRUCTURAL PROPERTIES OF CALCIA POWDERS DERIVED FROM EGGSHELL WASTE

This study investigates the effects of calcination temperature and holding time on the structural properties of calcia (CaO) powders. The raw material used in this study is chicken eggshell waste, which was cleaned, dried, ground, and sieved for uniform particle size. The synthesis of calcia powder was performed by calcining the powder at 900°C and 1000 °C for 5, 10, and 15 hours. XRD, BET, and SEM analyses were employed to evaluate crystal structure, textural properties, and microstructure of the calcined powders. The Rietveld analysis reveals the identified crystalline phases were calcia up to 95.6 mol% and calcium hydroxide as secondary phase. Results indicate that higher calcination temperatures and extended holding times increase particle size and reduce BET surface area, significantly altering pore size distribution. Specifically, elevated temperatures promote sintering and grain growth, leading to smaller average pore radii and decreased total pore volume. The BET surface area ranges from 7.431 m2/g to 1.772 m2/g for samples calcined at 900 °C and from 3.202 m²/g to 0.711 m²/g for samples calcined at 1000 °C. Correspondingly, the average particle radius increases from 183.51 nm to 769.55 nm at 900 °C and from 425.83 nm to 1918.10 nm at 1000 °C as the holding time extends. BJH analysis reveals that longer holding times broaden pore size distribution due to the merging of smaller pores.

Solid-State Reaction Synthesis of CoSb2O6-Based Electrodes Towards Oxygen Evolution Reaction in Acidic Electrolytes: Effects of Calcination Time and Temperature

Mitigating global warming necessitates transitioning from fossil fuels to alternative energy carriers like hydrogen. Efficient hydrogen production via electrocatalysis requires high-performance, stable anode materials for the oxygen evolution reaction (OER) to support the hydrogen evolution reaction (HER) at the cathode. Developing noble metal-free electrocatalysts is therefore crucial, particularly for acidic electrolytes, to avoid reliance on scarce and expensive metals such as Ir and Ru. This study investigates a low-cost, solvent-free solid-state synthesis of CoSb2O6, focusing on the influence of calcination time and temperature. Six samples were prepared and characterized using powder X-ray diffraction (PXRD), energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) analysis, field-emission scanning electron microscopy (FESEM), and electrochemical techniques. A non-pure CoSb2O6 phase was observed across all samples. Electrochemical testing revealed good short-term stability; however, all samples exhibited Tafel slopes exceeding 200 mV dec−1 and overpotentials greater than 1 V. The sample calcined at 600 °C for 6 h showed the best performance, with the lowest Tafel slope and overpotential, attributed to its high CoSb2O6 content and maximized {110} facet exposure. This work highlights the role of calcination protocols in developing Co-based OER catalysts and offers insights for enhancing their electrocatalytic properties.

The Impact of Ultra-Low Temperature Quenching Treatment on the Pore Structure of Natural Quartz Sand

The effective removal of impurities from natural quartz is a very challenging subject, but there is no relevant study on the mesoscopic structure of quartz sand particles, and there is still a lack of direct evidence on the structure-activity relationship between mesoscopic structure and purification effect. In this paper, the effects of calcination temperature, calcination time, quenching frequency and grinding frequency on the formation of mesoscopic fractures in natural quartz sand were studied, and a linear regression model was established by fractal and differential methods. The results show that the cracked structure of quartz sand and its variation law have remarkable fractal characteristics, and that thermal expansion and phase transformation are the main factors affecting the cracked structure and specific surface area of quartz sand. The non-phase change thermal expansion results in the formation of semi-closed wedge-shaped fractures in the open fractures of quartz sand, resulting in a significant decrease in the specific surface area of the cracked sand. On the contrary, the phase change expansion is conducive to the generation of more Me10 mesoporous fractures and the increase of the specific surface area of cracked sand. In addition, thermal stress and mechanical force are more likely to form Me50 and Me10 mesoporous cracks, where the average proportion of Me50 is higher than 75%. Based on this, the linear regression model between the fractal dimension and the pore volume distribution, SBET, is further established, and the correlation coefficient R2 is mostly above 96%. In addition to offering insightful findings for the investigation of the structure-activity relationship between the purification effect and the mesoscopic structure of quartz sand, this paper also establishes the groundwork for the advancement of high purification technologies for natural quartz sand.

EFFECT OF CALCINATION TEMPERATURE ON THE PHASE COMPOSITION AND MAGNETIC PROPERTIES OF THE BOEHMITE WITH ADSORBED FERROCENE

The effect of calcination temperature in air of finely dispersed boehmite powders with ferrocene adsorbed at room temperature from n-hexane solution on X-ray diffraction patterns and EPR spectra of calcined samples was studied. It has been shown that calcination in air of boehmite samples with adsorbed ferrocene leads to the decomposition of ferrocene molecules, stabilization of two types of magnetic centers in the structure of boehmite (at 200 and 400°C) and aluminum oxide (at 600°C) caused by two types of magnetic centers -Fe3+ ions with g-factor values, equal to 4.3 and 2.0. The signal at g = 4.3 is attributed to isolated Fe3+ ions in the structure of boehmite and aluminum oxide in a local field of oxygen anions with a rhombic environment. The signal at g = 2.0 is most likely due to Fe3+ ions bound by dipole interaction for samples with a low concentration of supported ferrocene (<0.1 wt.%) and superpara/ferromagnetic FeOx particles for samples of the calcination product of boehmite with a high content (>0.1 wt.%) of ferrocene. With increasing content of adsorbeded ferrocene, concentrations of Fe3+ ions with g-factor values equal to 4.3 and 2.0 grow disproportionately, and mainly the growth of the concentration of superpara/ferromagnetic FeOx particles on the oxide surface is observed.

The effect of calcination temperature on the structure and activity relationship of V/Ti catalysts for NH3-SCR

Calcination temperature can remarkably influence the physicochemical properties of V2O5/TiO2 catalysts by adjusting the redox sites and acid sites.

Effect of Calcination Temperature and Holding Time on MCAS Formation through the Solid-State Method: Structural and Phase Analysis

Effect of Calcination Temperature and Holding Time on MCAS Formation through the Solid-State Method: Structural and Phase Analysis

The effect of manganese doping and calcination temperature on polarization, structural and magnetic properties of multiferroic LuFe(1-)Mn O3 system

The effect of manganese doping and calcination temperature on polarization, structural and magnetic properties of multiferroic LuFe(1-)Mn O3 system

Tailoring Structural, Microstructural, Dielectric and Gas Sensing Properties of SnO2 Nanoparticles: Size Matters

This manuscript reports on the characteristics of SnO2 nanoparticles (NPs) prepared using the conventional sol-gel technique and showcases the effect of calcination temperature on crystal structure, size, and gas-sensing properties. Rietveld refinement of diffraction profiles of SnO2 NPs calcined at 400 °C [SnO2@400] and 600 °C [SnO2@600] showed that both the samples possess tetragonal phase having space group P 4 / 2 mnm . FESEM microimages of SnO2@400 and SnO2@600 were subjected to morphological analysis using an image processing method. The results showed that the grains exhibited swelling as the calcination temperature increased as per the Ostwald ripening process. High-resolution transmission electron microscopic (HRTEM) image depicted (110) lattice plane orientation with d = 0.34 nm consistent with XRD studies. Thus, the dielectric constant ε ′ was increased from 38 to 56 as the temperature rose to 600 °C from 400 °C. Simultaneously, electrical resistance increased from 0.77 × 106 Ω to 1.27 × 106 Ω with rise in the calcination temperature of SnO2 NPs from 400 °C to 600 °C. The investigation on sensing acetone gas revealed that the SnO2@600 sample possessed the maximum sensing response along with a shorter recovery time compared with SnO2@400.

In situ hydrothermal synthesis of visible light active sulfur doped TiO2 from industrial TiOSO4 solution

A cost-effective industrial TiOSO4 solution was employed to fabricate visible light active sulfur-doped titanium dioxide (S-TiO2) via a facile hydrothermal method. The effect of calcination temperature on morphology, particle size, crystallinity, and photocatalytic property of S-TiO2 was systematically investigated. Successful incorporation of sulfur into TiO2 was confirmed by carbon-sulfur analysis, X-ray photoelectron spectroscopy (XPS), and Energy dispersive spectrometer (EDS). The research results demonstrated that calcination temperature significantly impacted the crystallinity, specific surface area, sulfur content, and light absorption properties of S-TiO2. The catalyst calcined at 400 °C revealed the highest photocatalytic activity, with a rate constant of 0.02408 min−1, approximately 25 times higher than commercial P25 catalyst. The higher activity was attributed to the synergistic effect of well-crystallized anatase phase, specific surface area, and red shift of spectral absorption.

Effect of Ethanol Treatment and Calcination Temperature on Water Vapor Adsorption properties of MCM-41.

MCM-41, a mesoporous material with a high surface area and tunable pore size, shows great potential for water vapor adsorption. However, due to its large pore size, the effective adsorption capacity at medium to low relative partial pressures is limited in adsorption chiller applications. In this work, MCM-41 was successfully synthesized at room temperature using cetyltrimethylammonium bromide (CTAB) as a templating agent. Pore size modulation was achieved by treating the MCM-41 gel with ethanol. The results indicated that ethanol likely exerted an inward force on the pore channels, reducing the pore size from 3.418 to 2.583 nm. The water vapor adsorption properties and hydrothermal stability of the ethanol-treated samples were significantly enhanced. Additionally, a dual-atmosphere calcination process at 450 °C was established, showing results comparable to the conventional 550 °C process in terms of template removal. The sample, which combined dual-atmosphere calcination with ethanol treatment, demonstrated a significant increase in the water vapor adsorption capacity, achieving a 1.3-fold improvement compared to the untreated sample. These results provide a feasible reference for the application of MCM-41 in adsorption chillers.

Energy-efficient Carbon-doped TiO2 for Visible Light Degradation of Methyl Orange: Preparation, Performance, and Mechanism

Water pollution caused by textile dyes has become a serious issue, making the treatment of sewage urgent. Carbon-doped TiO2 (C-doped TiO2), using alkanes and polyols as carbon sources, has been found to be light-responsive in degrading dyes. However, there is a lack of studies on the interfacial interaction between carboxylic acids and TiO2. Therefore, citric acid, a triprotic, hexadentate carboxylic acid, was used to dope TiO2 through solvothermal-calcination. The effects of carbon content and calcination temperature on the photodegradation performance of C-doped TiO2 were investigated. The band gap energy of C-doped TiO2 was found to be narrower (2.67 eV) than that of undoped TiO2 (2.88 eV). After carbon doping, the absorption band extended from the UV to the visible regions, lowering the energy required for electron excitation. The functional groups present on C-doped TiO2 assisted in the adsorption of methyl orange (MO), assisting in photodegradation. Only the anatase phase of TiO2 was observed at calcination temperatures between 250 and 400 °C. Photoluminescence analysis revealed that a lower carbon content and slightly higher calcination temperature resulted in better interfacial charge separation and transfer efficiency. The 10 wt% C-doped TiO2 calcined at 300 °C demonstrated the best MO photodegradation efficiency of 62.1% under visible light illumination. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Effect of calcination temperature on the performance of hydrothermally grown cerium dioxide (CeO2) nanorods for the removal of Congo red dyes

This study investigates the transformation of CeO2 nanostructures through various calcination temperatures and their subsequent impact on morphological, structural, and photocatalytic properties. X-ray diffraction (XRD) analysis reveals the presence of cerium oxycarbonate in the uncalcined samples, transitioning to a face centered cubic CeO2 phase post-calcination at 500°C. The scanning electron microscopy (SEM) imaging delineates a morphological evolution from distinct, rod-like structures in the uncalcined state to sintered, agglomerated forms as calcination temperatures ascend from 500°C to 800°C. The crystallite size, calculated using Scherrer's Equation, displayed a proportional increase with temperature. The photocatalytic degradation of Congo red dye under UV light was analyzed using UV-Vis spectroscopy, with the calcined samples exhibiting varying degrees of adsorption and photocatalytic activity. The study found that higher calcination temperatures correlate with increased photocatalytic performance, potentially due to enhanced crystallinity. This assertion is supported by pseudo-first-order kinetic modeling, indicating improved photocatalytic efficiency with higher calcination temperatures, underlined by increasing rate constants. These findings underscore the intricate relationship between calcination-induced morphological and structural changes and the photocatalytic prowess of CeO2 nanostructures.

Cu–Zn Catalysts Derived From ZIF‐8 Applied in Ethynylation of Formaldehyde for 1,4‐Butynediol Synthesis: The Positive Effect of Carbon Layers

ABSTRACTCu‐based catalysts applied in ethynylation reaction of formaldehyde for 1,4‐butynediol synthesis has been widely concerned. The activity and stability of Cu‐based catalyst is still a challenging task in this field. Here, Cu–Zn catalysts derived from ZIF‐8 are prepared by a coprecipitation method and applied in ethynylation reaction of formaldehyde. All catalysts were characterized through thermogravimetric, x‐ray diffraction, N2 physical adsorption–desorption, transmission electron microscopy, H2‐temperture‐programmed reduction, x‐ray photoelectron spectroscopy, and Raman and Fourier transform infrared analysis. The effect of calcination temperature of ZIF‐8 on the catalyst structures and ethynylation performances are all investigated. The results show that CuO5h‐ZnO400 catalyst has the best catalytic activity, with a formaldehyde conversion of 98% and 1,4‐butynediol selectivity of 100%. It is mainly due to the presence of highly dispersed and small particle CuO. Moreover, CuO3h‐ZnO400 catalyst prepared by optimized conditions can further improve the stability in ethynylation reaction due to more carbon species on the surface of ZnO. The more carbon contents in Cu–Zn catalyst contribute to the ethynylation activity and stability due to the interaction between Cu and C species favoring Cu2C2 formed. In addition, the ethynylation reaction mechanism catalyzed by Cu–Zn catalyst is illustrated carefully. The Cu–Zn catalysts derived from ZIF‐8 can provide some ideas for the application in ethynylation reaction of formaldehyde for 1,4‐butynediol synthesis.

Green synthesis of ZnO nanoparticles using Cosmos caudatus: Effects of calcination temperature and precursor type on photocatalytic and antimicrobial activities

Green synthesis of ZnO nanoparticles using Cosmos caudatus: Effects of calcination temperature and precursor type on photocatalytic and antimicrobial activities

Effect of calcination temperature on the physicochemical properties of natural hydroxyapatite derived from Catla fish bone

Abstract The aim of this research is to investigate the effect of calcination temperature on the crystallinity and composition of hydroxyapatite derived from Catla bone waste using thermal calcination approach. To achieve this, bone waste was first cleaned and then thermally treated at varying calcination temperatures (650°C, 750°C, and 900°C) to yield hydroxyapatite. XRD and FTIR analyses revealed that elevating the calcination temperature leads to higher crystallinity and a reduction in carbonate content within the hydroxyapatite structure. FTIR analysis also revealed that calcination of Catla bone from 650 to 750 ·C will form B-type carbonated hydroxyapatite. Nonetheless, a biphasic calcium phosphate mixture, which is ascribed to the decomposition of hydroxyapatite phase into tricalcium phosphate was observed for product sintered at 900 ·C. Meanwhile, EDS analysis revealed the existence of trace elements, including Mg, K, Na, Si, and Sr within the crystal structure of all calcined products, irrespective of the employed calcination temperature. In conclusion, a calcination temperature of 650 °C emerged as the optimal choice for HAp extraction from Catla fish bone. This temperature not only maintained lower crystallinity but also preserved carbonate content, yielding single-phase HAp with properties well-suited for bone tissue engineering application.