The effect of ammonia solution concentration on the synthesis process of MgFe2O4 based on natural iron sand as adsorbent of Pb ions

2020 ◽  
Author(s):  
Eko A. Setiadi ◽  
Nining S. Asri ◽  
Yara A. Wijayanti ◽  
Anggito P. Tetuko ◽  
Perdamean Sebayang
Keyword(s):  
Solution Concentration ◽  
Ammonia Solution ◽  
Synthesis Process ◽  
Natural Iron ◽  
Pb Ions

scholarly journals Growth of SiO2 microparticles by using modified Stὂber method: Effect of ammonia solution concentration and TEOS concentration

2020 ◽  
Author(s):  
Shrestha Bhattacharya ◽  
Aishik Basu Mallick ◽  
Mrinal Dutta ◽  
Sanjay K. Srivastava ◽  
P. Prathap ◽  
...  
Keyword(s):  
Solution Concentration ◽  
Ammonia Solution ◽  
Method Effect ◽  
Teos Concentration

scholarly journals Impact of Preparative pH on the Morphology and Photocatalytic Activity of BiVO4

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Yongbiao Wan ◽  
Sihong Wang ◽  
Wenhao Luo ◽  
Lianhua Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Ammonia Solution ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blue Solution ◽  
Absorption Performance ◽  
The Impact

Adjusting pH with an ammonia solution during the synthesis, single-crystalline BiVO4has been prepared using Bi(NO3)3·5H2O and NH4VO3as starting materials through aqueous-phase precipitation at room temperature. The prepared samples are characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM). The impact of pH on structure, surface morphology, visible-light photocatalytic activity, and light absorption performance of BiVO4is explored and discussed. During the synthesis process, neither extremely acidic (low pH) nor basic (high pH) conditions are desirable for the formation of BiVO4in monoclinic phase. The highest photocatalytic performance on the degradation of a methylene blue solution is observed under pH=7.0for BiVO4in monoclinic scheelite, which is attributed to its small grain size and marked surface oxygen evolution ability.

Synthesis of SnO2 Nanoparticles with Varying Particle Sizes and Morphologies by Hydrothermal Method

2011 ◽  
Vol 415-417 ◽  
pp. 585-589
Author(s):  
Dong Xin Wang ◽  
Xu Jin Bao ◽  
Jing Ming Zhong ◽  
Ben Shuang Sun
Keyword(s):  
Hydrothermal Method ◽  
Tin Oxide ◽  
Heating Temperature ◽  
Great Influence ◽  
Solution Concentration ◽  
Ammonia Solution ◽  
Particle Sizes ◽  
Tin Chloride ◽  
Tin Oxide Nanoparticles ◽  
Xrd Patterns

Using ammonia solution and tin chloride as the precursors: tin oxide nanoparticles with different particle sizes and morphologies were synthesised by varying the concentration, heating temperature and ripening time via hydrothermal method. The particles synthesised were characterised by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The TEM micrographs show that rod-like nanoparticles were synthesised when the SnCl4 solution concentration was less than 1.0 mol/L, which was changed to oval shape when the concentration increased above 2.0 mol/L. Polygonal shaped nanoparticles were observed at 220 °C for 48 hours. It was also found that changing temperature had little effect on the morphology but great influence on the size of the particles, which increased from 10 nm to 120 nm from 160 °C to 220 °C and 12 nm to 55 nm from 6 h to 48 h at 200 °C, respectively. XRD patterns indicated that all of nanoparticles synthesised were tin oxide.

SYNTHESIS AND CHARACTERIZATION OF 3D CARBON NANOTUBES

MRS Advances ◽  
2018 ◽  
Vol 3 (1-2) ◽  
pp. 103-108
Author(s):  
Oxana V. Kharissova ◽  
Beatriz Ortega Garcia ◽  
Patsy Y. Arquieta Guillén ◽  
Hugo V. Galindo Cuevas ◽  
Romeo Selvas Aguilar
Keyword(s):  
Carbon Nanotubes ◽  
3D Structure ◽  
Three Dimensional ◽  
Multiwall Carbon Nanotubes ◽  
Solution Concentration ◽  
Synthesis Process ◽  
Synthesis Time ◽  
Research Areas ◽  
Functionalization Of Carbon Nanotubes ◽  
Nanoparticles Of Silver

ABSTRACTA nanomaterial that attracts the attention in a variety of research areas is multiwall carbon nanotubes (MWCNTs), due to their good mechanical proprieties, and high electrical and thermal conductivity. For this reason, the preparation of three-dimensional (3D) structures from them draws interest because it opens new horizons to produce materials with novel properties and useful applications. In this investigation the synthesis of 3D nanotube carbon (nanoforest type) functionalized with nanoparticles of silver, aluminum, and iron was studied. A 3D structure was produced in the form of aligned microchannels. The functionalization of carbon nanotubes with nanoparticles of silver, aluminum or iron during the synthesis process of carbon nanotubes, was carried out through spray-pyrolysis with different synthesis time and solution concentration. The results were characterized through microscopy SEM, TEM and Raman’s spectroscopy.

scholarly journals Defects Promoted Topotactic Transformation from Co(OH)2 Nanodiscs To Co3O4 Nano Octahedra

2019 ◽  
Vol 25 (3) ◽  
pp. 335-339
Author(s):  
Fei HUI ◽  
Chunhui WANG ◽  
Yanhui CHEN ◽  
Junfeng ZHOU ◽  
Pierce MAGUIRE ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrogen Bonds ◽  
Ammonia Solution ◽  
Synthesis Process ◽  
Image Simulation ◽  
Transmission Electron ◽  
Edge Dislocations ◽  
Topotactic Transformation

Topotactic transformation was one of the most frequently related processes in the synthesis process of cobalt oxide nanomaterials. Microstructural evolution studies of this process inform and enable the process of controlling the shape of the final products. One such topotactic transformation was investigated here, the transition from Co(OH)2 hexagonal nano platelets to Co3O4 octahedra by a hydrothermal method in an ammonia solution. Evolution of phase and microstructure was studied during different stages of the reaction to reveal the criteria which prompt this transformation. A phase transformation from Co(OH)2 to CoOOH and hence to Co3O4 was observed. High resolution transmission electron microscopy and image simulation were utilised to disclose the role of defects in the topotactic transformation. A high density of defects including edge dislocations and displacements was found on the surface of dried Co(OH)2 nano platelets. The coexistence of CoOOH domains embedded in the Co(OH)2 surface indicates the absence of the hydrogen bonds of the starting materials. The breaking of hydrogen bonds leads to bonding variation and the further creation of defects, finally prompting the transformation from Co(OH)2 to CoOOH. The breaking of hexagonally arranged hydrogen bonds creates seeds for the formation of Co3O4. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.22005

scholarly journals Application of AgNPs/rGO Modified Nylon Fabric in Strain Sensing

2021 ◽  
Vol 2109 (1) ◽  
pp. 012017
Author(s):  
Yongqiang Yang ◽  
Yongsong Tan ◽  
Qun Wang ◽  
Yihu Shu ◽  
Qinsheng Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Screen Printing ◽  
Strain Sensor ◽  
Solution Concentration ◽  
Ammonia Solution ◽  
Strain Sensing ◽  
Nylon Fabric ◽  
Reduced Graphene ◽  
Different Strains

Abstract The graphene oxide slurry was printed on the pre-stretched and non-pre-stretched nylon fabric by screen printing, and immersed in silver ammonia solution of different concentrations, and then reduced to obtain silver nanoparticles/reduced graphene oxide (AgNPs/rGO) modified nylon fabric with excellent conductivity. The surface morphology of the fabric was observed, and the performances of the fabric sensor that was scraped with graphene oxide slurry between the pre-stretched and non-pre-stretched states were explored. The resistance responses of the nylon fabric finished with different concentrations of silver ammonia solution under different strains (1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%) were investigated. The results showed that the nylon strain sensor was more sensitive and stable when the graphene oxide slurry was scraped in the pre-stretched state, and while the silver ammonia solution concentration was 10 mg/mL, the nylon fabric had maximum sensitivity and lowest hysteresis performance.

Surface Modification of Carbon Electrodes for Supercapacitor Using Ammonia Water

2011 ◽  
Vol 396-398 ◽  
pp. 1265-1268 ◽  
Author(s):  
Ren Qing Wang ◽  
Mei Gen Deng
Keyword(s):  
Surface Modification ◽  
Activated Carbon ◽  
Specific Capacitance ◽  
Carbon Materials ◽  
Solution Concentration ◽  
Ammonia Solution ◽  
Constant Current ◽  
Power Performance ◽  
Ammonia Water ◽  
Constant Current Charge

In this work, activated carbon was modified by ammonia water. Cyclic voltammetry and constant current charge-discharge were used to characterize the electrochemical performance of the samples in 1.0 mol/L Et4NBF4-PC solution. As a result, optimal conditions for surface modification of activated carbon have been examined as an ammonia solution concentration of 5wt.%. Specific capacitance can be improved significantly by surface modification of carbon materials. The specific capacitance of the carbon modified with 5.0wt.% ammonia water reached 114 F/g at a current density of 3.0 mA/cm2, which is 14% higher than that of untreated sample. In addition, the modified carbon materials possess excellent power performance.

Influence of Precursor Solution Concentration on Zinc Oxide Nanostructures by Hydrothermal Growth

2014 ◽  
Vol 875-877 ◽  
pp. 562-566
Author(s):  
Zong Bo Huang ◽  
X.P. Zou ◽  
G.Q. Yang ◽  
X.M. Lv ◽  
C.L. Wei ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Precursor Solution ◽  
Solution Concentration ◽  
Ammonia Solution ◽  
Zinc Nitrate ◽  
Hydrothermal Growth ◽  
Zinc Oxide Nanostructures ◽  
Oxide Nanostructures ◽  
Precursor Solution Concentration

In this paper, various ZnO nanostructures, such as rods, flowers were grown on indium-tin-oxide (ITO) substrates by hydrothermal growth at low temperature, using the different concentrations of equimolar (1:1) zinc nitrate (Zn (NO3)26H2O) and methenamine (C6H12N4) mixed as precursors solution, and adding ammonia solution to control the pH levels. SEM, XRD were utilized to characterize morphologies and crystal structures of ZnO. It was indicated that the concentration of precursor solution leads to the significantly changes in the nanostructured ZnO. The possible growth mechanism is discussed in this work.

Sonocatalyzed Ammonothermal Preparation of Fine Lithium Niobate Powders

2008 ◽  
Vol 55-57 ◽  
pp. 37-40
Author(s):  
A. Rujiwatra ◽  
N. Thammajak ◽  
Y. Chimupala ◽  
Pitak Laoratanakul
Keyword(s):  
Lithium Niobate ◽  
Single Phase ◽  
Fine Powder ◽  
Critical Factor ◽  
Solution Concentration ◽  
Ammonia Solution ◽  
Lithium Nitrate ◽  
Ultrasonic Activation ◽  
Fine Powders ◽  
Single Phase Formation

The so-called sonocatalyzed ammonothermal technique has been developed for the preparation of lithium niobate fine powders from commercially as-received niobium pentoxide and lithium nitrate. The present work shows that the application of ultrasonic activation prior to the ammonothermal treatment can produce a single phase lithium niobate fine powder at a relatively low temperature of 220°C. The influences of Li-precursors, ammonia solution concentration, reaction temperature and time, as well as Li:Nb mole ratio - which is evidentially the most critical factor promoting a single phase formation - are discussed.

Calcium Carbonate Production through Direct Mineral Carbon Dioxide Sequestration

2014 ◽  
Vol 699 ◽  
pp. 1020-1025 ◽  
Author(s):  
Amin Azdarpour ◽  
Radzuan Junin ◽  
Mohammad Asadullah ◽  
Hossein Hamidi ◽  
Muhammad Manan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Particle Size ◽  
Calcium Carbonate ◽  
Reaction Temperature ◽  
Carbon Dioxide Sequestration ◽  
Solution Concentration ◽  
Ammonia Solution ◽  
Carbonate Production ◽  
Calcium Carbonates ◽  
Fgd Gypsum

Mineral carbon dioxide sequestration provides a leakage free and permanent method of CO2 disposal to produce environmentally benign and stable solid carbonates. FGD gypsum as a source of calcium was proposed as the potential feedstock in this study. The purpose of this laboratory study was to investigate the effects of reaction parameters such as CO2 pressure, reaction temperature, particle size, and ammonia solution concentration on calcium carbonate purity through Merseburg process. Increasing the reaction temperature as well as the pressure was very effective in improving the calcium carbonate purity. High purity calcium carbonate was produced when reaction temperature and CO2 was increased to 400 °C and 70 bar, resulting in 93% and 94% purity, respectively. Experimental results showed that reducing particle size was also effective in enhancing the calcium carbonate purity in which the smallest particles produced higher purity calcium carbonates rather than larger particles. The role of ammonia solution on calcium carbonate purity was found to be beneficial in improving the calcium carbonate purity in which increasing the ammonia solution increased calcium carbonate purity significantly in all experiments.

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