scholarly journals Biosynthesis and characterization of zinc ferrite (ZnFe2O4) via Antidesma bunius L. fruit extract

2021 ◽  
Vol 926 (1) ◽  
pp. 012061
Author(s):  
V A Fabiani ◽  
F I P Sari ◽  
Nur’aini ◽  
S A Putri
Keyword(s):  
Calcination Temperature ◽  
High Intensity ◽  
Zinc Ferrite ◽  
Coprecipitation Method ◽  
Ftir Analysis ◽  
Fruit Extract ◽  
Calcination Temperatures ◽  
Wave Numbers ◽  
Diffraction Peaks

Abstract Biosynthesis of ZnFe2O4 via Antidesma bunius L fruit extract has been carried out. In this synthesis, Zn(NO3)2.6H2O and Fe(NO3)3.9H2O were used which act as precursors of Zn2+ and Fe3+ ions with a coefficient ratio of 1:2 using the coprecipitation method with variations in calcination temperatures of 500 °C, 600 °C and 700 °C. The precursor used is NaOH. XRD data showed that there are diffraction peaks of ZnFe2O4 in all samples but at a calcination temperature of 700,°C the diffraction peaks of ZnFe2O4 with high intensity are more visible at 2Θ = 31.78°, 34.42°, 35.2°, 36.22°, 56.61° this peak corresponds to the peak ZnFe2O4 diffraction (JCPDS 22-1012) in addition there is also a peak of ZnO at 2Θ = 31.7°, 34.4°, 36.2°, 47.5°, 62.8°, 66.5° and 69.2° (JCPDS 36-1451). FTIR analysis showed that the Zn-O stretching group was at wave numbers 837 cm-1, 870 cm-1, 1058 cm-1, 1065 cm-1, and 1350 cm-1. The Zn-O-Zn strain is found at wave numbers 1350 cm-1, 1633 cm-1, and 1634 cm-1, respectively. The appearance of these bonding groups proves that the synthesis of ZnFe2O4 has been formed.

scholarly journals Characterization of Varietal Differences in Essential Oil Components of Hops (Humulus lupulus) by SFC–FTIR Spectroscopy

2000 ◽  
Vol 83 (3) ◽  
pp. 621-626 ◽  
Author(s):  
Rita H Auerbach ◽  
Kenan Dost ◽  
George Davidson
Keyword(s):  
Essential Oil ◽  
Chromatographic Method ◽  
Flow Cell ◽  
Humulus Lupulus ◽  
Ftir Analysis ◽  
Varietal Differences ◽  
Wave Numbers ◽  
Oil Components

Abstract A supercritical fluid chromatographic method combined with Fourier-transform infrared spectroscopy detection (SFC–FTIR) was developed for determination of varietal differences in essential oil constituents in hops (Humulus lupulus). Infrared spectra (IR) of the major constituents of essential oil of hops were taken as films deposited on AgCl discs and compared with those obtained after chromatographic separation in the IR flow-cell with supercritical carbon dioxide (scCO2). Spectra from AgCl discs were comparable to those in scCO2, but in scCO2 most of the bands appeared approximately 8–10 cm−1 to higher wave numbers. Open-tubular SFC–FTIR analysis of the essential oil of 4 different hop varieties was performed. The SFC–FTIR chromatograms showed differences in the location and relative intensity of the peaks depending on the variety, which was further confirmed by consideration of their FTIR spectra.

scholarly journals Synthesis and Characterization of Polystyrene/CuO-Fe2O3 Nanocomposites from Natural Materials as Hydrophobic Photocatalytic Coatings

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Ratnawulan Ratnawulan ◽  
Ramli Ramli ◽  
Ahmad Fauzi ◽  
Sukma Hayati AE
Keyword(s):  
Contact Angle ◽  
Calcination Temperature ◽  
Sessile Drop ◽  
Sol Gel ◽  
Basic Material ◽  
Copper Ferrite ◽  
Natural Materials ◽  
Hydrophobic Coating ◽  
Calcination Temperatures

This study reports on the synthesis, characterization of polystyrene(PS)/CuO-Fe2O3 nanocomposites, and their application as hydrophobic coatings. CuO and Fe2O3 materials were synthesized from natural materials by the milling method. Meanwhile, the PS/CuO-Fe2O3 nanocomposites were synthesized by the sol-gel method. Furthermore, the hydrophobic coating on the glass substrate was made by the spin-coating. To obtain highest value of contact angle, the composition of both CuO and Fe2O3 in nanocomposite as well as calcination temperatures were varied. Sample characterization was conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet visible (Uv-Vis) spectrophotometry analysis. The Sessile drop method was used to determine the contact angle of the layer. The results showed that PS/CuO-Fe2O3 nanocomposite was successfully obtained with a crystal size between 40–52 nm and grain size of 92 nm. In addition to the basic material of composites, hematite and tenorite, the presence of copper ferrite phase was also identified. The CuO-Fe2O3 composition and its large calcination temperature also plays an effective role in the magnitude of the contact angle. The highest value of contact angle obtained was 125.46° at 3:1 composition and calcination temperature of 200 °C. We found that the PS/CuO-Fe2O3 composite was hydrophobic, but the photocatalyst activity was very small at 0.24%.

scholarly journals FTIR study of hydrotalcite

2018 ◽  
Vol 11 (2) ◽  
pp. 147-156
Author(s):  
Miroslava Mališová ◽  
Michal Horňáček ◽  
Jozef Mikulec ◽  
Pavol Hudec ◽  
Vladimír Jorík
Keyword(s):  
Calcination Temperature ◽  
Spinel Structure ◽  
Ftir Analysis ◽  
Ftir Study ◽  
Calcination Temperatures ◽  
The Third ◽  
Two Samples ◽  
Co Precipitation

Abstract The aim of the research was the study of aluminium-magnesium hydrotalcite by FTIR analysis and detection of differences in structure due to calcination. Three types of samples were analysed. In the first two samples, cobalt was added into the structure and the third sample contained nickel and zinc. Hydrotalcite was prepared by one of the most common methods of hydrotalcite preparation, co-precipitation. After preparation, the samples were calcined at temperatures from 150 °C to 750 °C. Samples were compared in terms of calcination temperature; but in case of samples containing cobalt, two samples to each other. The most significant changes were noticed in the 500–700 cm−1 region, where a spinel structure was formed at higher calcination temperatures.

Synthesis and Characterization of Stabilized Tetragonal Nano Zirconia by Precipitation Method

2019 ◽  
Vol 56 ◽  
pp. 142-151
Author(s):  
Hassan Shokry ◽  
Marwa Elkady ◽  
Hesham Hamad
Keyword(s):  
Phase Transformation ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
Average Crystallite Size ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
Calcination Temperatures ◽  
Ft Ir ◽  
20 Nm

Nano sized ZrO2 nanopowder was synthesized by precipitation method. Phase transformation was investigated as a function of calcination temperature by XRD, SEM , and FT-IR. It is indicated that the thermal anneling from 400 to 800 °C resulted in increasing the average crystallite size from 12 to 20 nm. As the calcination temperature increased, the crystallite size and the agglomeration were increased. The increase in the monoclinic content and grain growth are caused by the calcination temperatures even calcination at 800 °C.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF Fe2O3 NANOPARTICLES USING Averrhoa bilimbi AS BIOMATERIAL CHELATING AGENT FOR NANOFLUIDS APPLICATION

2017 ◽  
Vol 13 (2) ◽  
pp. 133 ◽  
Author(s):  
Arie Hardian ◽  
Alvi Aristia Ramadhiany ◽  
Dani Gustaman Syarif ◽  
Senadi Budiman
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Chelating Agent ◽  
Xrd Analysis ◽  
Solid Particles ◽  
X Ray Diffraction ◽  
Calcination Temperatures ◽  
Basic Fluid ◽  
Sol Gel Synthesis

<p>The aim of this work was to determine the effect of calcination temperature on the characteristics of Fe<sub>2</sub>O<sub>3</sub> nanoparticles (NPs) in sol-gel synthesis. The obtained Fe<sub>2</sub>O<sub>3 </sub>NPs was then used as material for preparation of Fe<sub>2</sub>O<sub>3</sub>-water nanofluids. Nanofluids is a mixture between basic fluid like water and 1 - 100 nm solid particles (nanoparticles). Nanoparticles of Fe<sub>2</sub>O<sub>3</sub> have been synthesized from the local mineral Jarosite using sol-gel method by using starfruit (<em>Averrhoa bilimbi</em>) extracts as the chelating agent. The calcination temperature was then varied from 500 ºC to 700 ºC for 5 hours. Based on the X-Ray Diffraction (XRD) analysis, the diffraction pattern of obtained Fe<sub>2</sub>O<sub>3</sub> was relevant with the JCPDS data No. 33-0664 for α-Fe<sub>2</sub>O<sub>3 </sub>with hexagonal crystallite system. The crystallite size (Scherrer’s Equation) of obtained α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles at calcination temperatures of 500 ºC, 600 ºC and 700 ºC was 50 nm, 48 nm and 40 nm, respectively. The Surface Area of Fe<sub>2</sub>O<sub>3</sub> NPs at temperature of 500 ºC, 600 ºC and 700 ºC was 45.45 m<sup>2</sup>/g; 26.91 m<sup>2</sup>/g and 17.51 m<sup>2</sup>/g, respectively. Fe<sub>2</sub>O<sub>3</sub>-water nanofluids was relativly stable with zeta potential of -39.60 mV; -46.37 mV and -41.57 mV, respectively for 500 ºC, 600 ºC and 700 ºC calcination temperature. The viscosity of Fe<sub>2</sub>O<sub>3</sub>-water nanofluids was higher than the viscosity of water. The critical heat flux (CHF) value of water-Fe<sub>2</sub>O<sub>3</sub> nanofluids was higher than the CHF water. The highest CHF value for nanofluids was obtained by using α-Fe<sub>2</sub>O<sub>3</sub> nanoparticles with calcination temperature of 600 ºC which 34.99 % of increment compare to the base fluid (water).</p>

scholarly journals REMOVAL OF DYES IN SONGKET WASTE WATER BY USING PHOTOCATALYST Chitosan-TiO2

2020 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Kurniawati - Oktarina
Keyword(s):  
Waste Water ◽  
Absorption Band ◽  
Uv Light ◽  
Liquid Waste ◽  
Water Medium ◽  
Ftir Analysis ◽  
Wave Numbers ◽  
Optimum Wavelength ◽  
Supporting Material

Photocatalyst is one of the catalysts that works when given a certain light and generally is a semiconductor that has a full valence band and an empty conduction band, such as TiO2. Synthesis of chitosan-TiO2 nanocomposite research has been carried out, nanocomposites produced from squid cartilage as chitosan-?. Nanocomposites are synthesized by combining chitosan as a supporting material and TiO2 which has a function as a high photocatalytic. Characterization of chitosan-TiO2 nanocomposites by FTIR and SEM / EDX which shows the functional groups and surface morphology of the nanocomposite. FTIR analysis shows the absorption band of O-Ti-O in the region of 678.98 cm-1 and the typical absorption of chitosan at wave numbers –OH 3425.58 cm 1, 3834.49 cm-1, and 3873.06 cm-1. From SEM / EDX analysis it can be seen that TiO2 is evenly distributed on the surface of chitosan. Then nanocomposite was applied with wrna procion in Palembang songket liquid waste. Chitosan-TiO2 nanocomposites from squid cartilage were able to degrade procion dyes in water medium with the help of UV light at the optimum wavelength of 520 nm, where the percentage of photodegradation was 54.47%. Which nanocomposite is also able to reduce the concentration of procion dyes from 5 mg / L to 1.9 mg / L with an initial acidity (pH) of 10.34 to 7.13. Key words: Photocatalyst, nanocomposites, Procion Red

EXAFS, XPS and TEM Characterization of SnO2-Based Emission Control Catalysts

1994 ◽  
Vol 368 ◽  
Author(s):  
Philip G. Harrison ◽  
Wayne Daniel ◽  
Nicholas C. Lloyd ◽  
Wan Azelee
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Relative Abundance ◽  
Emission Control ◽  
Exafs Data ◽  
Calcination Temperatures ◽  
Chromium Vi ◽  
Tem Characterization

ABSTRACTCatalysts formed by sorption of Cr(VI) on to tin(IV) oxide have been investigated by EXAFS, XPS and TEM. The latter shows that uncalcined catalysts comprise uniform, homogeneous particles of dimensions 2nm which increase to 4nm on calcination at 400°C. Calcination at higher temperatures results in an increase in particle size to 20nm × 30nm at 600°C, ca. 60nm at 800°C, and 90–100nm at 1000°C. XPS data show the evolution of chromium(III) species upon calcination and both chromium(VI) and chromium(III) species exist at all calcination temperatures. Chromium K-edge XANES also shows the presence of tetrahedral chromium(VI) species at all calcination temperatures, but the relative abundance decreases with increase in calcination temperature. Corresponding EXAFS data indicate that the uncalcined catalyst contains sorbed four-coordinated {Cr2O7} species whereas calcination produces six-coordinated {CrO6} species together with some residual tetrahedrally coordinated chromium. EXAFS data show that adsorbed {Cu(H2O)6} is the copper(II) species present prior to calcination of CuII-SnO2 catalysts.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

scholarly journals The Importance of Thermal Treatment on Wet-Kneaded Silica–Magnesia Catalyst and Lebedev Ethanol-to-Butadiene Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 579
Author(s):  
Sang-Ho Chung ◽  
Adrian Ramirez ◽  
Tuiana Shoinkhorova ◽  
Ildar Mukhambetov ◽  
Edy Abou-Hamad ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Calcination Temperature ◽  
Catalytic Properties ◽  
Catalyst Preparation ◽  
Preparation Methods ◽  
Calcination Temperatures ◽  
Alternative Process ◽  
Magnesium Silicates

The Lebedev process, in which ethanol is catalytically converted into 1,3-butadiene, is an alternative process for the production of this commodity chemical. Silica–magnesia (SiO2–MgO) is a benchmark catalyst for the Lebedev process. Among the different preparation methods, the SiO2–MgO catalysts prepared by wet-kneading typically perform best owing to the surface magnesium silicates formed during wet-kneading. Although the thermal treatment is of pivotal importance as a last step in the catalyst preparation, the effect of the calcination temperature of the wet-kneaded SiO2–MgO on the Lebedev process has not been clarified yet. Here, we prepared and characterized in detail a series of wet-kneaded SiO2–MgO catalysts using varying calcination temperatures. We find that the thermal treatment largely influences the type of magnesium silicates, which have different catalytic properties. Our results suggest that the structurally ill-defined amorphous magnesium silicates and lizardite are responsible for the production of ethylene. Further, we argue that forsterite, which has been conventionally considered detrimental for the formation of ethylene, favors the formation of butadiene, especially when combined with stevensite.

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