scholarly journals Synthesis of Silica Particles Using Ultrasonic Spray Pyrolysis Method

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 463
Author(s):  
Srecko Stopic ◽  
Felix Wenz ◽  
Tatjana-Volkov Husovic ◽  
Bernd Friedrich
Keyword(s):  
Spray Pyrolysis ◽  
Sol Gel ◽  
Ultrasonic Spray Pyrolysis ◽  
Silica Particles ◽  
Cement Industry ◽  
Submicron Particles ◽  
Spherical Particles ◽  
Spray Pyrolysis Method ◽  
X Ray ◽  
Ultrasonic Spray

Silica has sparked strong interest in hydrometallurgy, catalysis, the cement industry, and paper coating. The synthesis of silica particles was performed at 900 °C using the ultrasonic spray pyrolysis (USP) method. Ideally, spherical particles are obtained in one horizontal reactor from an aerosol. The controlled synthesis of submicron particles of silica was reached by changing the concentration of precursor solution. The experimentally obtained particles were compared with theoretically calculated values of silica particles. The characterization was performed using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). X-ray diffraction, frequently abbreviated as XRD, was used to analyze the structure of obtained materials. The obtained silica by ultrasonic spray pyrolysis had an amorphous structure. In comparison to other methods such as sol–gel, acidic treatment, thermal decomposition, stirred bead milling, and high-pressure carbonation, the advantage of the ultrasonic spray method for preparation of nanosized silica controlled morphology is the simplicity of setting up individual process segments and changing their configuration, one-step continuous synthesis, and the possibility of synthesizing nanoparticles from various precursors.

LPG Synthesis from Syngas over Cu/ZnO-Pd-β Catalysts Prepared by Ultrasonic Spray Pyrolysis

2015 ◽  
Vol 659 ◽  
pp. 252-256
Author(s):  
Sudarat Chaiwatyothin ◽  
Wittawat Ratanathavorn ◽  
Tharapong Vitidsant ◽  
Prasert Reubroycharoen
Keyword(s):  
Spray Pyrolysis ◽  
Fixed Bed ◽  
Ultrasonic Spray Pyrolysis ◽  
Product Distribution ◽  
Fixed Bed Reactor ◽  
Spherical Particles ◽  
Gaseous State ◽  
X Ray ◽  
Ultrasonic Spray ◽  
Co Conversion

Synthesis of nanoCu/ZnO catalyst for LPG production was prepared by ultrasonic spray pyrolysis (USP). Hollow spherical particles were obtained by USP technique using an aqueous solution of Cu (NO3)3.6H2O and Zn (NO3)3.3H2O with different concentration of 0.05, 0.1 and 0.5 molar under the pyrolysis temperatures of 600, 700 and 800°C. Mists of the solution were generated from the precursor solution by ultra sonic vibrators at frequency of ~1.7 MHz. The physicochemical properties of catalysts were characterized by X-ray diffraction, temperature-programmed reduction, scanning electron microscope, nitrogen adsorption-desorption, and energy dispersive X-ray spectrometer. The results showed that increasing in precursor concentration resulted in a large particle and particles size distributed in a range of 0.63-1.21 μm. Particles prepared at pyrolysis temperature 700°C exhibited homogeneous in size and shape compared to other temperature. The catalytic activity of nanoCu/ZnO-Pd-β catalysts was performed in a fixed-bed reactor for synthesizing LPG. The reaction took place at 260°C, 3.0 MPa, and the ratio of H2/CO = 2/1. All the products from the reactor were in gaseous state, and analyzed by on-line gas chromatography. The results showed that %CO conversion was high but decreased rapidly with increasing reaction time. Cu/ZnO catalyst prepared by co-precipitation gave higher %CO conversion than that prepared by ultrasonic spray pyrolysis. Moreover, hydrocarbon product distribution for Cu/ZnO catalyst produced at concentration 0.1 M 700°C by ultrasonic spray pyrolysis gave the highest LPG selectivity.

scholarly journals NdFeB Magnets Recycling Process: An Alternative Method to Produce Mixed Rare Earth Oxide from Scrap NdFeB Magnets

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 716
Author(s):  
Elif Emil Kaya ◽  
Ozan Kaya ◽  
Srecko Stopic ◽  
Sebahattin Gürmen ◽  
Bernd Friedrich
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis ◽  
Leach Liquor ◽  
Spray Pyrolysis Method ◽  
Ndfeb Magnets ◽  
X Ray ◽  
Ultrasonic Spray ◽  
Pyrolysis Method

Neodymium iron boron magnets (NdFeB) play a critical role in various technological applications due to their outstanding magnetic properties, such as high maximum energy product, high remanence and high coercivity. Production of NdFeB is expected to rise significantly in the coming years, for this reason, demand for the rare earth elements (REE) will not only remain high but it also will increase even more. The recovery of rare earth elements has become essential to satisfy this demand in recent years. In the present study rare earth elements recovery from NdFeB magnets as new promising process flowsheet is proposed as follows; (1) acid baking process is performed to decompose the NdFeB magnet to increase in the extraction efficiency for Nd, Pr, and Dy. (2) Iron was removed from the leach liquor during hydrolysis. (3) The production of REE-oxide from leach liquor using ultrasonic spray pyrolysis method. Recovery of mixed REE-oxide from NdFeB magnets via ultrasonic spray pyrolysis method between 700 °C and 1000 °C is a new innovative step in comparison to traditional combination of precipitation with sodium carbonate and thermal decomposition of rare earth carbonate at 850 °C. The synthesized mixed REE- oxide powders were characterized by X-ray diffraction analysis (XRD). Morphological properties and phase content of mixed REE- oxide were revealed by scanning electron microscopy (SEM) and Energy-dispersive X-ray (EDX) analysis. To obtain the size and particle size distribution of REE-oxide, a search algorithm based on an image-processing technique was executed in MATLAB. The obtained particles are spherical with sizes between 362 and 540 nm. The experimental values of the particle sizes of REE- oxide were compared with theoretically predicted ones.

scholarly journals Mixed Oxides NiO/ZnO/Al2O3 Synthesized in a Single Step via Ultrasonic Spray Pyrolysis (USP) Method

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Duygu Yeşiltepe Özcelik ◽  
Burçak Ebin ◽  
Srecko Stopic ◽  
Sebahattin Gürmen ◽  
Bernd Friedrich
Keyword(s):  
Spray Pyrolysis ◽  
Mixed Oxides ◽  
Ultrasonic Spray Pyrolysis ◽  
Single Step ◽  
Spray Pyrolysis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasonic Spray ◽  
Oxide Phases ◽  
The Many

Mixed oxides have received remarkable attention due to the many opportunities to adjust their interesting structural, electrical, catalytic properties, leading to a better, more useful performance compared to the basic metal oxides. In this study, mixed oxides NiO/ZnO/Al2O3 were synthesized in a single step via the ultrasonic spray pyrolysis method using nitrate salts, and the temperature effects of the process were investigated (400, 600, 800 °C). The synthesized samples were characterized by means of scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and Raman spectroscopy analyses. The results showed Al2O3, NiO–Al2O3 and ZnO–Al2O3 systems with spinel phases. Furthermore, the Raman peaks supported the coexistence of oxide phases, which strongly impact the overall properties of nanocomposite.

scholarly journals Efficient Visible Light Photocatalytic Oxidation of NO on F- and N-Codoped SphericalTiO2Synthesized via Ultrasonic Spray Pyrolysis

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Jianhui Huang ◽  
Wahkit Cheuk ◽  
Yifan Wu ◽  
Frank S. C. Lee ◽  
Wingkei Ho
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Spray Pyrolysis ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Diffuse Reflectance Spectroscopy ◽  
Ultrasonic Spray Pyrolysis ◽  
Spray Pyrolysis Method ◽  
X Ray ◽  
Ultrasonic Spray

The fluorine- and nitrogen-codoped TiO2was synthesized by ultrasonic spray pyrolysis method with titanium tetrafluoride and urea as precursor. The codoped TiO2was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). Nitric oxide (NO) photocatalytic oxidation in gas-phase medium was employed as a probe reaction to evaluate the photocatalytic reactivity of the catalysts. The results indicated that spherical codoped TiO2photocatalysts with unique puckered surface were obtained by this method. The codoped catalysts have solely anatase crystalline structure. The optical characterization of the codoped catalysts showed that the codoped samples could be excited by visible light photons in the 400–550 nm and could efficiently oxidize NO under visible light irradiation. The mechanism of special morphology formation of prepared codoped TiO2structure is also discussed.

Preparation of Titanium-doped Indium Oxide Films by Ultrasonic Spray Pyrolysis Method

2013 ◽  
Vol 454 (1) ◽  
pp. 63-69
Author(s):  
Surapong Panyata ◽  
Sukum Eitssayeam ◽  
Gobwut Rujijanagul ◽  
Tawee Tunkasiri ◽  
Sumnuk Sirisoonthorn ◽  
...  
Keyword(s):  
Spray Pyrolysis ◽  
Indium Oxide ◽  
Oxide Films ◽  
Ultrasonic Spray Pyrolysis ◽  
Spray Pyrolysis Method ◽  
Ultrasonic Spray ◽  
Pyrolysis Method ◽  
Indium Oxide Films ◽  
Ultrasonic Spray Pyrolysis Method

scholarly journals Ultraviolet and violet-blue emission of Zn doped MgO/mg(OH)2 particles prepared by one step spray pyrolysis method

2018 ◽  
Vol 1 (1) ◽  
pp. 57-66
Author(s):  
Fenfen Fenda Florena ◽  
◽  
Dwindra Wilham Maulana ◽  
Ferry Faizal ◽  
Bambang Mukti Wibawa ◽  
...  
Keyword(s):  
Spray Pyrolysis ◽  
Doping Concentration ◽  
Blue Emission ◽  
Spherical Shape ◽  
Spherical Particles ◽  
Spray Pyrolysis Method ◽  
Excitation Spectra ◽  
X Ray ◽  
Pyrolysis Method ◽  
One Step

Spherical particles of Zn doped MgO were prepared by one-step spray pyrolysis method. The crystalline nature and particle size of the samples were characterized by X-ray diffraction analysis (XRD). The morphology of samples was studied by scanning electron microscope (SEM) and the presence of Zn in the sample was confirmed by energy dispersive X-ray analysis (EDX). The optical properties of the samples were investigated using photoluminescence spectroscopy (PL) analysis to obtain excitation and emission spectra of the samples. Results indicated that the doped MgO particles exhibited a cubic structure without hexagonal wurtzite structure as the Zn concentrations were increased. Spherical shape and porous particles are found with increasing of doping concentration. The optical band gap of MgO altered with the addition of doping concentration. A considerable redshift of about ~0.08 – 0.13 eV in the excitation spectra of 2.22 eV emission band was revealed in Zn doped MgO samples. It was highlighted that Zn doped MgO prepared by the spray pyrolysis generated emission at UV-Vis wavelength required for many applications.

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