scholarly journals Syntheses of Nanostructured Magnesium Carbonate Powders with Mesoporous Structures from Carbon Dioxide

2021 ◽  
Vol 11 (3) ◽  
pp. 1141
Author(s):  
Fernando J. Rodríguez-Macías ◽  
José E. Ortiz-Castillo ◽  
Erika López-Lara ◽  
Alejandro J. García-Cuéllar ◽  
José L. López-Salinas ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Magnesium Carbonate ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
Aqueous Synthesis ◽  
Synthesis Time ◽  
X Ray

In this work, we present the results of two synthesis approaches for mesoporous magnesium carbonates, that result in mineralization of carbon dioxide, producing carbonate materials without the use of cosolvents, which makes them more environmentally friendly. In one of our synthesis methods, we found that we could obtain nonequilibrium crystal structures, with acicular crystals branching bidirectionally from a denser core. Both Raman spectroscopy and X-ray diffraction showed these crystals to be a mixture of sulfate and hydrated carbonates. We attribute the nonequilibrium morphology to coprecipitation of two salts and short synthesis time (25 min). Other aqueous synthesis conditions produced mixtures of carbonates with different morphologies, which changed depending on drying temperature (40 or 100 °C). In addition to aqueous solution, we used supercritical carbon dioxide for synthesis, producing a hydrated magnesium carbonate, with a nesquehonite structure, according to X-ray diffraction. This second material has smaller pores (1.01 nm) and high surface area. Due to their high surface area, these materials could be used for adsorbents and capillary transport, in addition to their potential use for carbon capture and sequestration.

Synthesis and Analysis of High Surface Area Vanadium Carbide Nanoparticles

2012 ◽  
Vol 585 ◽  
pp. 95-99 ◽  
Author(s):  
M. Mahajan ◽  
K. Singh ◽  
O.P. Pandey
Keyword(s):  
Surface Area ◽  
Vanadium Carbide ◽  
High Surface ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
X Ray ◽  
Transmission Electron ◽  
Product Powder ◽  
Scanning Electron

Vanadium carbide is known for its applications due to extreme hardness and high melting point. In this present work, vanadium carbide nanoparticles have been synthesized in a specially designed stainless steel autoclave by solvothermal route using vanadium pentoxide (V2O5) as precursor along with a hydrocarbon acetone (C3H6O) in the presence of reducing agent magnesium (Mg). The optimization of reaction time was studied at constant temperature of 800oC. The product powder was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and Brunauer – Emmett – Teller (BET) techniques. The results indicate that the product was vanadium carbide having particle size of about 30 nm with high surface area.

scholarly journals Preparation of Ammonia Dealuminated Metakaolinite and Its Adsorption against Bixin

2020 ◽  
Vol 20 (4) ◽  
pp. 791
Author(s):  
Winda Rahmalia ◽  
Jean-Francois Fabre ◽  
Thamrin Usman ◽  
Zéphirin Mouloungui
Keyword(s):  
Surface Area ◽  
Room Temperature ◽  
High Surface ◽  
High Surface Area ◽  
Total Pore Volume ◽  
Adsorption Properties ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudo Second Order

This study aims to prepare dealuminated metakaolinite which has a high surface area by using NH4OH as an activator. The natural kaolinite sample was treated at 600 °C for 6 h in order to obtain metakaolinite. A dealuminated metakaolinite was then prepared by the repeated activation method using concentrated ammonia (5 M NH4OH) at room temperature. Depending on the nature of each type of material, natural kaolinite, NH4OH treated kaolinite, metakaolinite and NH4OH treated metakaolinite were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET-N2) measurements. XRD and FTIR results confirmed that structural transformation from kaolinite to metakaolinite had occurred. According to SEM-EDS data, the activation of metakaolinite by NH4OH allowed the dealumination of metakaolinite. The increase in the Si/Al ratio was almost twice as high as in kaolinite. BET-N2 analysis showed that the specific surface area and the total pore volume increased significantly after activation. Its adsorption properties were tested against bixin. Bixin adsorption on dealuminated metakaolinite followed pseudo-second order kinetic where k2 = 0.20 g/mg min. The adsorption isotherm followed the Langmuir model where qm = 0.72 mg/g.

Flower Buds Like MgO Nanoparticles: From Characterisation to Indigo Carmine Elimination

2018 ◽  
Vol 73 (11) ◽  
pp. 975-983 ◽  
Author(s):  
A. Modwi ◽  
L. Khezami ◽  
Kamal K. Taha ◽  
Hajo Idriss
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Indigo Carmine ◽  
High Surface Area ◽  
Dye Adsorption ◽  
Nitrogen Adsorption ◽  
Magnesium Carbonate ◽  
Flower Buds ◽  
X Ray ◽  
Pseudo Second Order

AbstractHere, we demonstrate a pyrolysis route for the synthesis of flower buds like magnesium oxide nanoparticles using a magnesium carbonate precursor without additional chemicals. The effect of heating at different time intervals upon the structure and morphology of the acquired nanostructures were investigated via X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and Fourier transformation infrared spectroscopy. Nitrogen adsorption was employed to study its porosity. The obtained data confirmed the formation of target nanoparticles that exhibited increasing sizes as pyrolysis time was lengthened. As a consequence a high surface area up to 27 m2 g−1 was recorded for the sample heated for 1 h duration. Furthermore, Indigo Carmine dye adsorption was carried out using the largest surface area species which showed an adsorption capacity of 158 mg g−1. The adsorption was found to comply with the Langmuir isotherm and it follows the pseudo-second-order kinetics. The diffusion process showed intra-particle along with film diffusion mode.

scholarly journals Growth of Hierarchically Structured High-Surface Area Alumina on FeCrAl Alloy Wires

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Chandni Rallan ◽  
Aaron Akah ◽  
Patrick Hill ◽  
Arthur Garforth
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
Entire Study ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Fecral Alloy ◽  
Time Periods ◽  
Metastable Alumina

The formation of metastable alumina phases due to the oxidation of commercial FeCrAl alloy wires (0.5 mm thickness) at various temperatures and time periods has been examined. Samples were isothermally oxidised in air using a thermogravimetric analyzer (TGA). The morphology of the oxidised samples was analyzed using an Electronic Scanning Electron Microscope (ESEM) and X-ray on the surface analysis was done using an Energy Dispersive X-Ray (EDX) analyzer. The technique of X-Ray Diffraction (XRD) was used to characterize the phase of the oxide growth. The entire study showed that it was possible to grow high-surface area gamma alumina on the FeCrAl alloy wire surfaces when isothermally oxidised above 800°C over several hours.

Preparation of High Surface Area Ni-SDC Cermets Using a Surfactant-Assisted Co-Precipitation Method

2006 ◽  
Vol 942 ◽  
Author(s):  
Sang Joon Park ◽  
Tae Wook Eom ◽  
Jae Eun Oh ◽  
Hae Kwang Yang ◽  
Kyung Hwan Kim
Keyword(s):  
Surface Area ◽  
Cetyltrimethylammonium Bromide ◽  
High Surface ◽  
High Surface Area ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Phases ◽  
Co Precipitation ◽  
Surfactant Assisted

ABSTRACTA surfactant-assisted co-precipitation method was employed for obtaining high surface area Ni-SDC with improved structural properties for SOFC applications. In the work, a cationic surfactant, cetyltrimethylammonium bromide(CTAB) was employed with NiCl2, SmCl3 and CeCl3 as precursors and NH4OH as mineralizer. The elimination of surfactants upon calcination gives rise to the formation of high surface area NiO-SDC. When calcined at 600°C, the powders with surface area of 249 m2/g, were obtained and the pore size was 14.45 nm. The powders consist of two phases, the cubic NiO and SDC confirmed with X-ray diffraction identification.

Effects of Surfactant Concentration on the Microstructures of TiO2 Hollow Spheres by Hydrothermal Method

2013 ◽  
Vol 634-638 ◽  
pp. 2189-2192 ◽  
Author(s):  
Lian Ying Lu ◽  
Lin Xu ◽  
Ting Ting Yin ◽  
Guo Hong Wang
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
High Surface ◽  
Photovoltaic Cells ◽  
Hollow Spheres ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hollow Structures ◽  
Good Penetration

TiO2 hollow spheres were prepared by hydrothermal method using CTAB, glucose and (NH4)2TiF6 as surfactant, template and titanium source, respectively. The microstructures of hollow spheres TiO2 were characterized with X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR). The results showed the concentration of the CTAB obviously influenced the morphology of hollow spheres TiO2. This synthesis route may also extend to the preparation of hollow structures of other metal oxides. Because of the large specific surface area, porous structure, and good penetration, the hierarchical TiO2-derived hollow spheres may find great applications in catalysis, photovoltaic cells and high surface area electrodes.

scholarly journals Salt-Mediated Au-Cu Nanofoam and Au-Cu-Pd Porous Macrobeam Synthesis

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1701 ◽  
Author(s):  
Fred Burpo ◽  
Enoch Nagelli ◽  
Lauren Morris ◽  
Kamil Woronowicz ◽  
Alexander Mitropoulos
Keyword(s):  
Surface Area ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Electronic Conductivity ◽  
High Surface Area ◽  
Three Dimensional ◽  
Synthesis Methods ◽  
X Ray ◽  
Sensing Applications ◽  
Metal Composition

Multi-metallic and alloy nanomaterials enable a broad range of catalytic applications with high surface area and tuning reaction specificity through the variation of metal composition. The ability to synthesize these materials as three-dimensional nanostructures enables control of surface area, pore size and mass transfer properties, electronic conductivity, and ultimately device integration. Au-Cu nanomaterials offer tunable optical and catalytic properties at reduced material cost. The synthesis methods for Au-Cu nanostructures, especially three-dimensional materials, has been limited. Here, we present Au-Cu nanofoams and Au-Cu-Pd macrobeams synthesized from salt precursors. Salt precursors formed from the precipitation of square planar ions resulted in short- and long-range ordered crystals that, when reduced in solution, form nanofoams or macrobeams that can be dried or pressed into freestanding monoliths or films. Metal composition was determined with X-ray diffraction and energy dispersive X-ray spectroscopy. Nitrogen gas adsorption indicated an Au-Cu nanofoam specific surface area of 19.4 m2/g. Specific capacitance determined with electrochemical impedance spectroscopy was 46.0 F/g and 52.5 F/g for Au-Cu nanofoams and Au-Cu-Pd macrobeams, respectively. The use of salt precursors is envisioned as a synthesis route to numerous metal and multi-metallic nanostructures for catalytic, energy storage, and sensing applications.

scholarly journals Synthesis of high surface area mesoporous silica SBA-15 by adjusting hydrothermal treatment time and the amount of polyvinyl alcohol

2019 ◽  
Vol 17 (1) ◽  
pp. 963-971
Author(s):  
Ridhawati Thahir ◽  
Abdul Wahid Wahab ◽  
Nursiah La Nafie ◽  
Indah Raya
Keyword(s):  
Mesoporous Silica ◽  
Surface Area ◽  
Hydrothermal Treatment ◽  
Pore Volume ◽  
Pore Diameter ◽  
High Surface ◽  
High Surface Area ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe high surface area of mesoporous silica SBA-15 has been synthesized successfully by hydrothermal treatment with direct addition of PVA, triblock copolymer (P123) as a direct structure agent and tetraethyl orthosilicate (TEOS) as a precursor. The mesoporous silica SBA-15 have been characterized with nitrogen physisorption, scanning electron microscopy, Fourier transformed infrared spectroscopy, and x-ray diffraction. Measurement of nitrogen sorption indicated that with the addition of PVA, the surface area is increased but the pore volume and pore diameter is not significantly. The short time of hydrothermal treatment (20 h) and using x-ray diffraction, showed that the morphological structure of silica SBA-15 can be changed to a orthorhombic crystal system. The result of the FTIR and SEM-EDX characteristic indicated the functional groups and morphology of the SBA-15 with a narrow pore size distribution. The BET method has exhibited the largest surface area 1726 m2/g, pore volume 1.4 cm3/g, and pore diameter 3.2 nm. It can be suggested that the silica mesoporous SBA-15 will have potential application prospect in catalysis, storage, and adsorbent.

scholarly journals Synthesis, characterization, and reactivity of tungsten oxynitride

1998 ◽  
Vol 13 (8) ◽  
pp. 2321-2327 ◽  
Author(s):  
Toby E. Lucy ◽  
Todd P. St. Clair ◽  
S. Ted Oyama
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Continuous Transformation ◽  
X Ray ◽  
Synthesis Conditions ◽  
Temperature Programmed ◽  
Temperature Programmed Reaction

High surface area tungsten oxynitride has been prepared by the temperature programmed reaction (TPR) of WO3 with NH3. All samples were characterized by x-ray diffraction (XRD), nitrogen physisorption, CO chemisorption, and elemental analysis. Samples were prepared at different heating rates (β), and a Redhead analysis yielded an activation energy for nitridation of 109 kJ mol−1. A heating rate of 0.016 K s−1 gave optimal synthesis conditions. Solid state intermediates were studied by interrupting the temperature program at various stages. No distinct suboxide phases were found using XRD. The nitridation step was determined to be a continuous transformation from oxide to oxynitride. Surface area, CO uptake, and nitrogen weight % were all found to increase as the reaction progressed. Reactivity experiments showed reasonable hydrodeoxygenation (HDO) and hydrodenitrogenation (HDN) activity, but little hydrogenation (HYD) or hydrodesulfurization (HDS) activity.

scholarly journals Developing Eco-Friendly and Cost-Effective Porous Adsorbent for Carbon Dioxide Capture

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1962
Author(s):  
Mahboubeh Nabavinia ◽  
Baishali Kanjilal ◽  
Noahiro Fujinuma ◽  
Amos Mugweru ◽  
Iman Noshadi
Keyword(s):  
Carbon Dioxide ◽  
Surface Area ◽  
Co2 Capture ◽  
High Surface ◽  
Scale Up ◽  
Polymer Networks ◽  
High Surface Area ◽  
Excellent Thermal Stability ◽  
Doped Polymers ◽  
Metal Doped

To address the issue of global warming and climate change issues, recent research efforts have highlighted opportunities for capturing and electrochemically converting carbon dioxide (CO2). Despite metal doped polymers receiving widespread attention in this respect, the structures hitherto reported lack in ease of synthesis with scale up feasibility. In this study, a series of mesoporous metal-doped polymers (MRFs) with tunable metal functionality and hierarchical porosity were successfully synthesized using a one-step copolymerization of resorcinol and formaldehyde with Polyethyleneimine (PEI) under solvothermal conditions. The effect of PEI and metal doping concentrations were observed on physical properties and adsorption results. The results confirmed the role of PEI on the mesoporosity of the polymer networks and high surface area in addition to enhanced CO2 capture capacity. The resulting Cobalt doped material shows excellent thermal stability and promising CO2 capture performance, with equilibrium adsorption of 2.3 mmol CO2/g at 0 °C and 1 bar for at a surface area 675.62 m2/g. This mesoporous polymer, with its ease of synthesis is a promising candidate for promising for CO2 capture and possible subsequent electrochemical conversion.

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