Effect of pH Value on the Synthesis of NiO Nanoparticles and Microstructure of NiO Based Composite Anode

2021 ◽  
Vol 317 ◽  
pp. 447-453
Author(s):  
Noor Hidayah Aniza Zakaria ◽  
Nafisah Osman

NiO nanoparticle was synthesized by a sol-gel method with three different pH values namely pH=1, 7 and 11, and then calcined at temperature of 450 ᵒC. The influence of different pH values on the physical properties of NiO nanoparticles were investigated by a particle size analyzer (PSA), field emission scanning electron microscope (FESEM) and X-ray diffractometer (XRD). Structural analysis confirmed that a cubic structure of NiO nanoparticle was obtained without any secondary phase for NiO powders prepared with pH=1, while the peak of secondary phase (Ni) appeared for NiO powders prepared with pH= 7 and 11. Morphological observation showed that the NiO nanoparticles prepared with pH=7 and 11 tend to form more agglomerates compared to one prepared with pH=1. The average diameter of NiO nanoparticles with pH 1, 7 and 11 were approximately in the range of 19-26 nm, 21-28 nm, and 24-30 nm, respectively. NiO powder that was synthesized with pH=1 was further used to prepare composite anode of NiO Nps-BaCe0.54Zr0.36Y0.1O2.95 (BCZY) powder. Unfortunately a composite of NiO Nps-BaCeO3-BaZrO3 was obtained instead of BCZY and governed by agglomerates with size in the range of 70-300 nm.

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Jothi M ◽  
Sowmiya K

Nickel Oxide (NiO) is an important transition metal oxide with cubic lattice structure. NiO is thermally stable that is suitable for tremendous applications in the field of optic, ceramic,glass, electro-chromic coatings, plastics, textiles, nanowires, nanofibers, electronics,energy technology, bio-medicine, magnetism and so on. In this present study, NiO nanoparticles were successfully synthesized by sol-gel technique. Nano-sols were prepared by dissolving Nickel-Chloride [NiCl2.6H2O] in NaOH solvent and were converted into nano structured gel on precipitation. A systematic change in preparation parameters like calcination temperature, time, pH value has been noticed in order to predict the influence on crystallite size. Then the prepared samples were characterized by the X-ray Diffraction Spectroscopic (XRD), UV-VIS Spectroscopy, Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). From XRD, the average crystalline-size has been calculated by Debye-Scherrer Equation and it was found to be 12.17 nm and the band gap energy of Nickel oxide (NiO) from UV studies reveals around 3.85 eV. Further, EDX and FTIR studies, confirm the presences of NiO nanoparticles. The SEM study exhibits the spherical like morphology of Nickel oxide (NiO). Further from PSA, the mean value of NiO nanoparticles has been determined.


2013 ◽  
Vol 678 ◽  
pp. 80-85 ◽  
Author(s):  
Krishnasamy Sakthivel ◽  
T. Venkatachalam

Thin films of TiO2 have been deposited on well cleaned glass substrates by Sol-Gel dip-drive coating technique. The films have been prepared at three different pH values (1, 3.5 & 9) of Sol and annealed in muffle furnace at 550°C for one hour and are allowed to cool to room temperature. The films were characterized by XRD, EDAX, SEM and UV-Vis Spectrophotometer. The as deposited films were found to be amorphous in nature. The annealed films exhibit anatase in crystalline structure. The EDAX results have shown that all the films are maintained with TiO2 in composition. The XRD results reveal that they are nano-crystalline in nature and the crystalline nature increases with pH of the Sol. The transmittance and absorbance spectra have shown that the films are transparent and band gap of the films are of the order of 3.2eV. The ab initio studies of TiO2 (using GGA) was performed with Vienna ab initio Simulation package and the band structure and effective masses of the electrons and holes were determined.


2015 ◽  
Vol 31 ◽  
pp. 93-102 ◽  
Author(s):  
Farrakh Shahzad ◽  
Karl Ettinger ◽  
Ilse Letofsky-Papst ◽  
Julia Weber ◽  
Peter Knoll

NiO nanoparticles are successfully prepared by sol-gel technique. A systematic change in preparation parameters like calcination temperature, calcination time and pH value has been done in order to study the influence on crystallite size. The prepared samples are characterized by X-ray diffractometer, Transmission electron microscopy, Energy dispersive x-rays analysis and Raman spectroscopy. It is shown that crystallite size mainly depends on the calcination temperature rather than pH value or calcination time.


2013 ◽  
Vol 821-822 ◽  
pp. 618-621
Author(s):  
Yan Hua Lu ◽  
Ming Su Song ◽  
Jie Lin

In this paper, nanosol of titanium dioxide was prepared by sol-gel method using tetrabutyl-titanate as a precursor. The Particle Size Analyzer test results showed that the average diameter of the particles was less than 10 nm, and most particle size ranged from 6nm to 16nm. The prepared mechanism was discussed and then applied to fixation of vegetable turmeric dyed tussah silk. The fixation results indicated that the rubber fastness and washing fastness increased remarkably and the K/S values changed a little.


2019 ◽  
Vol 17 (41) ◽  
pp. 75-81
Author(s):  
Baha Fakhry Shehab

Hydrophobic silica aerogels were successfully preparation by an ambient pressure drying method from sodium silicate (Na2SiO3) with different pH values (5, 6, 7, 8, 9 and 10). In this study, acidic HCl (1M), a basic NH4OH (1M) were selected as a catalyst to perform the surface modification in a TMCS (trimethylchlorosilane) solution. The surface chemical modification of the aerogels was assured by the Fourier transform infrared (FTIR) spectroscopic studies. Other physical properties, such as pore volume and pore size and specific surface area were determined by Brunauer-Emmett- Teller (BET) method. The effect of pH values on the bulk density of aerogel. The sol–gel parameter pH value in the sol, have marked effects on the physical properties of the silica aerogels produced by this technique. The density and the hydrophobic tendency of the aerogels were significantly influenced.


2021 ◽  
pp. 123-133
Author(s):  
Anastasiya Igorevna Smirnova ◽  
Alla Borisovna Dyagileva ◽  
Aleksandra Yevgen'yevna Prismakova ◽  
Ol'ga Yur'yevna Derkacheva

The concept and flow model of a structured dispersed system obtained on the basis of sulfate lignin modified by Sol-gel method in the presence of aluminum-containing components in the form of nepheline concentrate are considered. The systems are mainly systems of non-Newtonian behavior, characterized by phenomena of destruction and formation of new structures in the shear flow, and the nature of the flow depends on the characteristics of interaction between system components, which are defined as their concentrations, and process conditions of the synthesis, at which the change of the adhesion forces between particles and at the moment cannot be generalized and described existing well-known equations of flow.As a result of the study, it was found that an increase in the concentration of sulfate lignin under various synthesis conditions, but with a constant amount of mineral component, leads to the formation of a new modified product, while there is a tendency to increase the parameters of kinematic viscosity and shear stress at the corresponding pH values of synthesis. Under conditions of excessive lignin concentrations of more than 400 mg/dm3, when self-organizing in the matrix of a new form, lignin dominance leads to a decrease in the strength characteristics of the polymer for all its forms obtained at different pH values. It is established that the kinematic viscosity and shear stress of water dispersions in this system depend on both the pH value of their synthesis and the concentration of the initial lignin, which determines the mechanisms of self-organization of the new modified structure.


2013 ◽  
Vol 319 ◽  
pp. 134-139
Author(s):  
Mehtap Demirel ◽  
Bunyamin Aksakal ◽  
Nese Basak

Hydroxyapatite (HA) based bone grafts were synthesized by sol-gel method at various pH values 5, 7, 9 and 12, respectively. In order to ascertain the influence of the obtained bone grafts on the morphology, sinterability and mechanical properties, each composition was sintered at 11500C, and quantitative phase analysis was characterized by XRD and FTIR. The microstructures were studied via SEM-EDX and the validation of mechanical properties was evaluated by compression and Vickers hardness tests. The density of HA synthesis samples with different pH values before and after sintering were measured. Besides, the cytotoxicity analysis were conducted for all grafts having various pH values. The experimental results revealed that the density and mechanical strenght of HA based bone grafts were increased with increasing pH value. The highest hardness and strength were obtained for the samples having pH=12. Furthermore, the samples with pH=12 exhibited the best densification and properties when compared to the samples at pH of 5, 7 and 9. The cytotoxicity tests also indicated that the pH=7-12 value showed no toxicity to osteoblast cells at 0,1 and 0,3 µM concentration, whereas HA synthesis sample at pH=5 value with 0,3 µM concentration induced significantly and reduced cell viability.


e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiangbo Wang ◽  
Zhong Xin

AbstractPolymethylsilsesquioxane (PMSQ) microspheres with an average diameter of 30nm to 6μm were prepared from methyltrimethoxysilane (MTMS) by a two-step sol-gel method in the presence of hexadecyl trimethyl ammonium chloride (HTAC). The reaction conditions including the concentration of HTAC, water/MTMS ratio, pH value and the temperature in condensation reaction were examined, and aggregation of the microspheres was not observed during the preparation process. Moreover, the structure and thermal stability of PMSQ microspheres were investigated by FT-IR, XRD, TGA, and so on.


1995 ◽  
Vol 18 (1) ◽  
pp. 53-60 ◽  
Author(s):  
S. D. Han ◽  
S. Y. Huang ◽  
G. Campet ◽  
M. A. Kennard ◽  
Y. M. Son

The evolution of the specific surface area and crystallite size of SnO2powders, prepared from a sol-gel process, was studied as a function of the calcination temperature of the stannic hydroxyde colloid, and for two different pH values (7.5 and 12.5) of the colloïdal state. The samples were characterized by TGA, IR spectroscopy, BET, and XRD techniques. The crystallite size and specific surface area were strongly affected not only by the calcination temperature, but unexpectedly, by the initial pH value of the colloïdal state. A framework model, relating the pH dependence to the resulting properties, is presented.


2000 ◽  
Vol 42 (7-8) ◽  
pp. 283-290 ◽  
Author(s):  
H.-C. Tsai ◽  
R.-A. Doong

A sol-gel based fiber-optic biosensor with acetylcholinesterase as the biorecognition element has been developed for the rapid determination of organophosphorus pesticides. Nine fluorescent indicators, acridine, acridine orange, neutral red, DAPI, rhodamine B, fluorescein, umbelliferone, FITC on celite and FITC-dextran, have been examined to optimize the fiber-optic system. Results showed that acridine and FITCs were sensitive to the change of pH value caused by the enzyme-substrate catalysis reaction. However, the sensitivity of acridine was 260 times lower than that of FITCs. Higher toxicity of acridine to acetylcholinesterase than FITC was also observed. Moreover, the high-molecular-weight FITC-dextran showed low leakage rate when immobilizing using sol-gel technology, showing that the FITC-dextran was a suitable pH sensitive fluorescent indicator for the OPPs biosensor. The response of the fiber-optic biosensor to the substrate, acetylcholine, was highly reproducible (RSD=3.5%). A good linearity of acetylcholine in the range from 0.5 to 20 mM was also obtained (R2=0.98). Furthermore, a 30% inhibition can be achieved in 30min when 152 ppb paraoxon was added into the system. The results show the possibility for real-time determination of organophosphorus pesticides by using the biosensor developed in this study.


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