scholarly journals SiO2:MgMnO3: An Efficient Heterogeneous Catalyst for One Pot Synthesis of 1H-Pyrazolo[1,2-b]phthalazine-5,10-dione Derivatives

2020 ◽  
Vol 32 (10) ◽  
pp. 2489-2494
Author(s):  
S.S. Sagar ◽  
R.P. Chavan
Keyword(s):  
Surface Area ◽  
Average Particle Size ◽  
Bet Surface Area ◽  
High Yield ◽  
Average Particle ◽  
One Pot ◽  
Short Reaction Time ◽  
Investigative Techniques ◽  
Current Procedure ◽  
Efficient Heterogeneous Catalyst

The present study deals with hydrothermal synthesis of SiO2 composite MgMnO3 catalyst. The obtained polycrystalline product was analyzed by using physical investigative techniques including XRD, SEM, EDAX, TEM, SAED and BET surface area. The product corresponded to average particle size of 100 nm by TEM images. The BET surface area was found 234.38 cm2/g for SiO2 composite MgMnO3 catalyst which indicates a good catalytic property. The synthesized catalyst was applied for the synthesis of 1H-pyrazolo[1,2-b]-phthalazine-5,10-dione in presence of ethanol as a solvent at 80 ºC. The current procedure and catalyst offers the gains of clean reaction, short reaction time, high yield, easy purification and financial availability of the catalyst.

An Efficient Multicomponent Synthesis of Octahydroquinazolinone Derivatives Using Novel Recyclable Grafted Fe APA-Complex Catalyst

2018 ◽  
pp. 30-35
Author(s):  
S. L. Sangle ◽  
S. S. Ghumare
Keyword(s):  
Bet Surface Area ◽  
High Yield ◽  
Catalyst Loading ◽  
Multicomponent Synthesis ◽  
Complex Catalyst ◽  
One Pot ◽  
Short Reaction Time ◽  
Investigative Techniques ◽  
The One ◽  
Octahydroquinazolinone Derivatives

Recoverable and recyclable heterogeneous grafted Fe-APA complex efficiently catalyzed the one-pot synthesis of octahydroquinazolinone derivatives via multicomponent reaction of dimedone, aromatic aldehyde, and urea using methanol as a solvent. The desired products were obtained with 84–96 % yields. The present approach offers several significants such as short reaction time, high yield, easy purification, minimum catalyst loading, and use as an alternative catalyst. Grafted Fe APA complex were synthesized and characterized by various analytical investigative techniques like FTIR, NMR, Mass, XRD, SEM, EDAX, TEM with SAED, and BET surface area.

Development of Heterostructured Ferroelectric SrZrO3/CdS Photocatalysts with Enhanced Surface Area and Photocatalytic Activity

2020 ◽  
Vol 20 (6) ◽  
pp. 3770-3779 ◽  
Author(s):  
Umar Farooq ◽  
Farheen Naz ◽  
Ruby Phul ◽  
Nayeem Ahmad Pandit ◽  
Sapan Kumar Jain ◽  
...  
Keyword(s):  
Particle Size ◽  
Dielectric Constant ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Room Temperature ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Bet Surface Area ◽  
Cds Nanoparticles ◽  
Average Particle

This paper reports the attempt to develop an efficient heterostructure photocatalyst by employing SrZrO3 as ferroelectric substrate with deposited nanostructured CdS semiconductor on the surface. Primarily bare SrZrO3 and CdS nanoparticles were synthesized by using polymeric citrate precursor and co-precipitation routes, respectively. The chemical deposition technique was used to develop the CdS over the surface of the pre-synthesized SrZrO3 nanoparticles. The synthesized bare nanoparticles and their heterostructure were characterized by XRD which shows the formation of orthorhombic and face centred cubic (FCC) phases of SrZrO3 and CdS, respectively. TEM was used to estimate the morphology and particle size of as-synthesized nanoparticles, which shows the average particle size of 14, 24 and 25 nm for SrZrO3, CdS and SrZrO3/CdS, respectively. The BET surface area of SrZrO3, CdS and SrZrO3/CdS samples was found to be 299, 304 and 312 m2/g respectively. Methylene blue was used as model pollutant to determine the photocatalytic activity of the synthesized nanomaterials. The heterostructure shows an enhanced activity as compared to bare nanoparticles. Dielectric constant and dielectric loss of the nanoparticles was investigated as a function of frequency at room temperature and as a function of temperature at 500 kHz. The room temperature dielectric constant for SrZrO3, CdS and SrZrO3/CdS was found to be 13.2, 17.8 and 25.5 respectively at 100 kHz.

scholarly journals The Characterization of Heterogeneous Nanocatalyst of Biohydroxyapatite-Lithium and its Application for Converting Malapari Seed Oil (Milletia pinnata L.) to Biodiesel

2018 ◽  
Vol 34 (4) ◽  
pp. 1817-1823
Author(s):  
I. Nengah Simpen ◽  
I. Made Sutha Negara ◽  
Ni Made Puspawati
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Seed Oil ◽  
Surface Acidity ◽  
Average Particle Size ◽  
Bet Surface Area ◽  
Average Particle ◽  
Bovine Bone ◽  
Heterogeneous Nanocatalyst ◽  
Surface Basicity

Heterogeneous nanocatalyst of biohydroxyapatite-lithium (HA-Li) has been prepared through modification of HA extracted from bovine bone waste with Li at various calcination temperatures (400-700oC). Characterizations of the heterogeneous catalysts were including surface acidity-basicity, functional groups, BET surface area, particle size, and surface morphology. Optimization of catalyst ratios (1-7%) with the best characterization was applied for converting Malapari seed oil (Milletia pinnata L.) to biodiesel. The characterization results showed that HA-Li catalyst calcinated at 600oChad the highest surface basicity and Lewis acid sites revealing specific functional group of O-Li at wavenumber of 1612.49 cm-1. BET surface area of HA-Li catalyst decreased with increased average particle size. SEM analysis suggested that morfology of catalysts formed stack of agglomerates. The highest yield of biodiesel obtained on a catalyst ratio of 5% was 88.16%. GC-MS analysis showed 10 peaks, and 5 of the peaks exhibiting the highest percentage area were identified as methyl oleic, methyl palmitic, methyl erusic, methyl stearic, and methyl linoleic.

Synthesis of Nanocrystalline α-Al2O3 Using a 2-Step Calcination Method

2006 ◽  
Vol 317-318 ◽  
pp. 199-202
Author(s):  
M.J. Cho ◽  
Sang Heum Youn ◽  
Jae Jun Kim ◽  
Kyu Hong Hwang ◽  
B.S. Jun ◽  
...  
Keyword(s):  
Surface Area ◽  
Metal Ion ◽  
Average Particle Size ◽  
Homogeneous Solution ◽  
Polymerization Reaction ◽  
Bet Surface Area ◽  
Complexing Agent ◽  
Average Particle ◽  
Al2o3 Particles ◽  
Α Al2o3

Nanocrystalline α-Al2O3 powders have been prepared by the pyrolysis of a resin compound of aluminum with polyester by a two-step calcination process. A polymeric precursor was prepared using a complexing agent to keep the metal ions in homogeneous solution, which gives sufficient flexibility for the system to exist homogeneously throughout the reaction without undergoing precipitation. The metal-ion-polyester resin forms the precursor material on complete polymerization reaction of aluminum nitrate, citric acid and ethylene glycol. A single-phase α-Al2O3 powder resulted after calcinations above 1150°C, but during heat treatment α-Al2O3 particles grow very fast by coalescence. So 2-step calcination was used, where the first step was done in a reducing atmosphere at above 1150°C and second calcinations were done in oxidizing atmosphere at the relatively low temperature of 1000°C. The precursors and the heat-treated final powders have been characterized by X-ray diffractometry, thermogravimetry , transmission electron microscopy(TEM), and BET surface area analysis. The nanocrystalline α-Al2O3 particles obtained by this 2-step calcinations method had an average specific surface area of >170m2/g, with an average particle size between 40 and 60nm.

scholarly journals Synthesis and characterization of Fe3O4 nanoparticles by electrodeposition and reduction methods

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
Nurrulhidayah Salamun ◽  
How Xin Ni ◽  
Sugeng Triwahyono ◽  
Aishah Abdul Jalil ◽  
Ainul Hakimah Karim
Keyword(s):  
Surface Area ◽  
Ferric Oxide ◽  
Fe3o4 Nanoparticles ◽  
Average Particle Size ◽  
Hydrogen Atmosphere ◽  
Bet Surface Area ◽  
Average Particle ◽  
Chromium Vi ◽  
Removal Of Heavy Metals ◽  
Reduction Methods

Magnetite (Fe3O4) nanoparticles have been studied extensively due to their good magnetic, optic and electric properties which offer a great potential of applications in many field especially in removal of heavy metals such as the adsorption of poisonous Cr(VI) ion in water. In addition, Fe3O4 is the only material that has up to now been use in human because it is the only material which is known to be biocompatible, without relevant toxicity in the applied dosage. In this study Fe3O4 nanoparticles were prepared by reduction of ferric oxide (Fe2O3) precursor at 598 K for 10, 20, 30 and 40 min. While, ferric oxide (Fe2O3) precursor was prepared by electrodeposition of iron plate in the N,N-dimethylformamide solvent and tetraethylammonium perchlorate and naphthalene as mediators at 263 K. Reduction of Fe2O3 was carried out with an isothermal heating at 598 K under hydrogen atmosphere. Fe2O3 and Fe3O4 were characterized with XRD, BET Surface area, FTIR, FESEM-EDX and TEM. The surface area of both Fe2O3 and Fe3O4 was 38 - 45 m2/g with the average particle size was 40 - 60 nm. The XRD result showed that the crystallinity of Fe3O4 increased with reduction time. The activity of Fe2O3 and Fe3O4 nanoparticles were tested on the adsorption of chromium (VI) at room temperature in which 30-40 % of Cr(VI) ion was adsorbed on the Fe2O3 and Fe3O4 nanoparticles.

scholarly journals Facile Hydrothermal and Solvothermal Synthesis and Characterization of Nitrogen-Doped Carbon Dots from Palm Kernel Shell Precursor

2021 ◽  
Vol 11 (4) ◽  
pp. 1630
Author(s):  
Yakubu Newman Monday ◽  
Jaafar Abdullah ◽  
Nor Azah Yusof ◽  
Suraya Abdul Rashid ◽  
Rafidah Hanim Shueb
Keyword(s):  
Carbon Dots ◽  
Batch Reactor ◽  
Average Particle Size ◽  
Research Work ◽  
Palm Kernel ◽  
Average Particle ◽  
One Pot ◽  
Palm Kernel Shell ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Carbon dots (CDs), a nanomaterial synthesized from organic precursors rich in carbon content with excellent fluorescent property, are in high demand for many purposes, including sensing and biosensing applications. This research focused on preparing CDs from natural and abundant waste, palm kernel shells (PKS) obtained from palm oil biomass, aiming for sensing and biosensing applications. Ethylenediamine and L-phenylalanine doped CDs were produced via the hydrothermal and solvothermal methods using one-pot synthesis techniques in an autoclave batch reactor. The as-prepared N-CDs shows excellent photoluminescence (PL) property and a quantum yield (QY) of 13.7% for ethylenediamine (EDA) doped N-CDs (CDs-EDA) and 8.6% for L-phenylalanine (L-Ph) doped N-CDs (CDs-LPh) with an excitation/emission wavelength of 360 nm/450 nm. The transmission electron microscopy (TEM) images show the N-CDs have an average particle size of 2 nm for both CDs. UV-Visible spectrophotometric results showed C=C and C=O transition. FTIR results show and confirm the presence of functional groups, such as -OH, -C=O, -NH2 on the N-CDs, and the X-ray diffraction pattern showed that the N-CDs were crystalline, depicted with sharp peaks. This research work demonstrated that palm kernel shell biomass often thrown away as waste can produce CDs with excellent physicochemical properties.

scholarly journals Commercial Cokes and Graphites as Anode Materials for Lithium - Ion Cells

1997 ◽  
Vol 496 ◽  
Author(s):  
David J. Derwin ◽  
Kim Kinoshita ◽  
Tri D. Tran ◽  
Peter Zaleski
Keyword(s):  
Electron Microscopy ◽  
Ethylene Carbonate ◽  
Average Particle Size ◽  
Chemical Properties ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Bet Surface Area ◽  
Average Particle ◽  
Electrochemical Characteristics ◽  
Wide Range

AbstractSeveral types of carbonaceous materials from Superior Graphite Co. were investigated for lithium ion intercalation. These commercially available cokes, graphitized cokes and graphites have a wide range of physical and chemical properties. The coke materials were investigated in propylene carbonate based electrolytes and the graphitic materials were studied in ethylene carbonate / dimethyl solutions to prevent exfoliation. The reversible capacities of disordered cokes are below 230 mAh / g and those for many highly ordered synthetic (artificial) and natural graphites approached 372 mAh / g (LiC6). The irreversible capacity losses vary between 15 to as much as 200 % of reversible capacities for various types of carbon. Heat treated cokes with the average particle size of 10 microns showed marked improvements in reversible capacity for lithium intercalation. The electrochemical characteristics are correlated with data obtained from scanning electron microscopy (SEM), high resolution transmission electron microscopy (TAM), X - ray diffraction (XRD) and BET surface area analysis. The electrochemical performance, availability, cost and manufacturability of these commercial carbons will be discussed.

Study on the kinetics of process for obtaining cobalt nanopowder by hydrogen reduction under isothermal conditions

2021 ◽  
Vol 1 (1) ◽  
pp. 49-56
Author(s):  
Hieр Nguyen Tien
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Average Particle ◽  
Isothermal Conditions ◽  
Electron Microscopes ◽  
Kinetics Of

The kinetics of metallic cobalt nanopowder synthesizing by hydrogen reduction from Co(OH)2 nanopowder under isothermal conditions were studied. Co(OH)2 nanopowder was prepared in advance by chemical deposition from aqueous solutions of Co(NO3)2 cobalt nitrate (10 wt.%) and NaOH alkali (10 wt.%) at room temperature, pH = 9 under continuous stirring. The hydrogen reduction of Co(OH)2 nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 270 to 310 °C. The crystal structure and composition of powders was studied by X-ray phase analysis. The specific surface area of samples was measured using the BET method by low-temperature nitrogen adsorption. The average particle size of powders was determined by the measured specific surface area. Particles size characteristics and morphology were investigated by transmission and scanning electron microscopes. Kinetic parameters of Co(OH)2 hydrogen reduction under isothermal conditions were calculated using the Gray–Weddington model and Arrhenius equation. It was found that the rate constant of reduction at t = 310 °C is approximately 1.93 times higher than at 270 °C, so the process accelerates by 1.58 times for 40 min of reduction. The activation energy of cobalt nanopowder synthesizing from Co(OH)2 by hydrogen reduction is ~40 kJ/mol, which indicates a mixed reaction mode. It was shown that cobalt nanoparticles obtained by the hydrogen reduction of its hydroxide at 280 °C are aggregates of equiaxed particles up to 100 nm in size where individual particles are connected to several neighboring particles by contact isthmuses.

Preparation and Antibacterial Performances of Electrocatalytic Zinc Oxide Nanoparticles with Diverse Morphologies

2021 ◽  
Vol 17 (9) ◽  
pp. 1824-1829
Author(s):  
Junlin Li ◽  
Xiangfei Li ◽  
Dong Liang ◽  
Xiaojuan Zhang ◽  
Qing Lin ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Surface Area ◽  
Zinc Oxide Nanoparticles ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zno Nps

This study exploits the potential of zinc oxide nanoparticles (ZnO-NPs) with diverse morphologies as catalysts and antibacterial agent. Spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were prepared by microemulsion method, solvent heat method and hydrothermal method, respectively. The structural characterizations of samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. XRD results revealed the formation of spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were all wurtzite crystal structure. SEM results showed that spherical ZnO-NPs had an average particle size of 30–40 nm, rod-shaped ZnO-NPs were about 500 nm long and 100 nm wide with obvious hexagonal crystals. Flower-shaped ZnO-NPs had a three-dimensional appearance with obvious petals. Results of electrochemical HER (Hydrogen evolution reaction) experiments revealed that spherical ZnO-NPs exhibited the highest electrocatalytic activity at the lowest potential voltage due to their largest specific surface area. The antibacterial property of ZnO-NPs samples were studied by the optical density method and disc diffusion method. All samples had antibacterial effects against E. coli. and flower-shaped ZnO-NPs showed the best antibacterial activity due to the largest surface area in comparison with spherical ZnO-NPs and rod-shaped ZnO-NPs, which promised the maximum Zn2+ release as bactericide mechanism that registered in the case of different ZnO-NPs morphologies.

scholarly journals Olive Leaves as Biotemplates for Enhanced Solar-Light Harvesting by a Titania-Based Solid

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1057
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
M. Carmen Herrera-Beurnio ◽  
Rafael C. Estévez ◽  
Francisco J. Urbano ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Average Particle Size ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Resonance Spectroscopy ◽  
Average Particle ◽  
Olive Leaves ◽  
Sem Images ◽  
X Ray

Olive leaves (by-product from olive oil production in olive mills) were used as biotemplates to synthesize a titania-based artificial olive leaf (AOL). Scanning electron microscopy (SEM) images of AOL showed the successful replication of trichomes and internal structure channels present in olive leaves. The BET surface area of AOL was 52 m2·g−1. X-ray diffraction (XRD) and Raman spectra revealed that the resulting solid was in the predominantly-anatase crystalline form (7.5 nm average particle size). Moreover, the synthesis led to a red-shift in light absorption as compared to reference anatase (gap energies of 2.98 and 3.2 eV, respectively). The presence of surface defects (as evidenced by X-ray photoelectron spectroscopy, XPS, and electron paramagnetic resonance spectroscopy, EPR) and doping elements (e.g., 1% nitrogen, observed by elemental analysis and XPS) could account for that. AOL was preliminarily tested as a catalyst for hydrogen production through glycerol photoreforming and exhibited an activity 64% higher than reference material Evonik P25 under solar irradiation and 144% greater under ultraviolet radiation (UV).

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