Porous Ceramic Humidity Sensors Using Sol-Gel Processed ZrTiO4 Nanoparticles

2006 ◽  
Vol 45 ◽  
pp. 1803-1808 ◽  
Author(s):  
I.C. Cosentino ◽  
E.N.S. Muccillo ◽  
F.M. Vichi ◽  
R. Muccillo
Keyword(s):  
Porous Ceramic ◽  
Mercury Porosimetry ◽  
Sol Gel ◽  
Average Particle Size ◽  
Nitrogen Adsorption ◽  
Zirconium Oxychloride ◽  
Average Particle ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Adsorption Analysis

Ceramic ZrTiO4 powders were prepared by a sol-gel method using zirconium oxychloride and titanium tetraisopropoxide. In situ high temperature X-ray diffraction results show that crystallization of the amorphous gel starts at 400°C. Single-phase ZrTiO4 nanoparticles of 46 nm average particle size, determined by nitrogen adsorption analysis, were obtained after heat treatment at 450°C for 1 h. After pressing these sinteractive powders, pellets with controlled pore size distribution were obtained by sintering at temperatures as low as 400°C. The analysis of pores by mercury porosimetry gives an average porosity of 45%. The electrical resistivity, determined by impedance spectroscopy measurements at 24°C under different humidity environments, shows the ability of these pellets to adsorb water vapor in the porous surfaces.

Synthesis and Characterization of Nanosized ZrTiO4 Powders Prepared by the Sol-Gel Method

2006 ◽  
Vol 530-531 ◽  
pp. 401-407 ◽  
Author(s):  
I.C. Cosentino ◽  
F.M. Vichi ◽  
E.N.S. Muccillo ◽  
R. Muccillo
Keyword(s):  
Mercury Porosimetry ◽  
Sol Gel ◽  
Average Particle Size ◽  
Nitrogen Adsorption ◽  
Zirconium Oxychloride ◽  
Average Particle ◽  
Titanium Tetraisopropoxide ◽  
Nanosized Powders ◽  
Gel Method ◽  
Sol Gel Method

Ceramic ZrTiO4 powders were prepared by a modified sol-gel method using zirconium oxychloride and titanium tetraisopropoxide. In situ high temperature X-ray diffraction results show that crystallization of the amorphous gel starts at 400 °C. Singlephase ZrTiO4 nanoparticles were obtained after heat treatment at 450 oC for 1 h. An average particle size of 46 nm has been determined by nitrogen adsorption analysis. After pressing these sinteractive powders, pellets with controlled pore size distribution were obtained by sintering at temperatures as low as 400 oC. The analysis of pores by mercury porosimetry shows an average porosity of 45 %. Pressing and sintering the nanosized powders prepared by that modified sol-gel technique produced pellets that are good candidates to be used in humidity sensing devices.

Synthesis of Cu Loaded TiO2 Nanoparticles for the Improved Photocatalytic Degradation of Rhodamine B

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660002 ◽  
Author(s):  
V. Kavitha ◽  
P. S. Ramesh ◽  
D. Geetha
Keyword(s):  
Titanium Dioxide ◽  
Rhodamine B ◽  
Sol Gel ◽  
Average Particle Size ◽  
Visible Spectrum ◽  
Xrd Analysis ◽  
Bandgap Energy ◽  
Average Particle ◽  
Titanium Tetraisopropoxide ◽  
Photoexcited Electron

Copper doped Titanium dioxide TiO2 nanoparticles were synthesized by sol–gel method using titanium tetraisopropoxide and copper sulfate as precursors. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), Photoluminesce spectroscopy (PL) and atomic force microscopy (AFM). XRD analysis confirms the formation of anatase titanium dioxide and average particle size was 35[Formula: see text]nm. Cu– TiO2 exhibits a shift in the absorption edge toward visible spectrum. The rate of recombination and transfer behavior of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. From SEM spherical shaped nanoparticles was observed. Comparing with pure TiO2 nanoparticles, Cu doped TiO2 photocatalyst exhibited enhanced photocatalytic activity under natural sunlight irradiation in the decomposition of rhodamine B aqueous solution. The maximum 97% of degradation efficiency of Rhodamine B was observed at 0.6% Cu–TiO2 within 180[Formula: see text]min. The photocatalytic efficiency of Rhodamine B of Cu doped TiO2 nanoparticle was higher than the pure TiO2, which could be attributed to the small crystallinity intense light absorption in Sunlight and narrow bandgap energy of Copper.

Photocatalytically Active Cotton Fabrics Produced with Anatase Synthesized Using a Low-Temperature Sol-Gel Process

2018 ◽  
Vol 762 ◽  
pp. 408-412
Author(s):  
Raivis Eglītis ◽  
Gundars Mežinskis
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Anatase Nanoparticles ◽  
Pre Treatment

In this work two different hydrosols were used to impregnate a commercially available cotton fabric with anatase nanoparticles to give it photocatalytic activity. To increase the activity, different pre-treatment methods were applied. The nanoparticle size was determined using dynamic light scattering and x-ray diffraction and the fabrics were examined using scanning electron microscopy. Photocatalytic activity was measured using the degradation of methyl-orange while irradiating the samples with UV light. The synthesis method allowed to produce anatase with an average particle size of 32 to 37 nm depending on the synthesis method used.

A Calcination Technology for Ultrafine La3NbO7 Powder Prepared by Sol-Gel Process

2011 ◽  
Vol 412 ◽  
pp. 271-274
Author(s):  
Ying Li ◽  
Qiang Xu ◽  
Ling Dai
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Average Particle Size ◽  
Complex Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Acid Complex ◽  
Calcination Process ◽  
Sol Gel Process

In order to prepare ultrafine La3NbO7 powder, a potential material for thermal barrier coatings, the calcination process of La3NbO7 was studied in this paper.The precursor of La3NbO7 was synthesized by using a citric acid complex method. A calcination process had been systematically investigated. The reaction temperature was determined by differential scanning calorimetry (DSC). The phase composition of powders was characterized by X-ray diffraction (XRD), and the morphology was obtained by scanning electron microscope (SEM). The results revealed that the single-phase La3NbO7 powder could be successfully prepared while the calcination temperature exceeded 800°C and a better morphology could be maintained at 800°C for 4 hours. Considering all above, an optimum calcination scheme was adopted at 800°C for 4 hours. The as-prepared La3NbO7 powders had a grain size of about 50nm and an average particle size of about 300nm.

Pb2+ and Ce3+ Doped SrZnO2: New Blue Luminescent Phosphors

2006 ◽  
Vol 916 ◽  
Author(s):  
Alp Manavbasi ◽  
Jeffrey C LaCombe
Keyword(s):  
Sol Gel ◽  
Average Particle Size ◽  
Broad Band ◽  
Emission Spectra ◽  
Broad Emission Band ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Broad Emission ◽  
Diffraction Patterns ◽  
Individual Particles

AbstractTwo new blue emitting phosphors, SrZnO2:Pb2+ and Ce3+ were synthesized by adipic acid and sucrose templated sol-gel routes, respectively. The resulting phosphor particles were fine, nanocrystalline and pure. The optimum activator concentrations were found to be 1 mol% Pb2+ and 12 mol% Ce3+. Two excitation bands centered at 283 and 317 nm, plus a weak shoulder at 275 nm were observed for Pb2+ doped samples, however only one broad excitation band with a maximum at 294 nm was observed for Ce3+ doped samples fired at 1000 °C for 2h. The emission spectra of SrZnO2:Pb2+ showed a very broad band extending from 374 to 615 nm with a maximum at ~455 nm which was ascribed to the 3P1 ¡æ 1S0 transition on the Pb2+ ions allowed by the strong spin-orbit (SO) coupling. Similarly, SrZnO2:Ce3+ showed a broad emission band extending from 374 to 609 nm and centered at 467 nm. This broad emission was attributed to the 5d1 ¡æ 4f1 transition of Ce3+ ions. The lower level 2F5/2 of the 4f1 is populated but the level 2F7/2 is almost empty at room temperature where all measurements were taken. The luminescence properties of Ce3+, K+ co-doped SrZnO2 revealed that the characteristic band locations remained the same and the ratio of emission to excitation intensities were constant. X-ray diffraction patterns showed that the SrZnO2 phase started to form at 900 °C (after 2 hrs), and the single-phase SrZnO2 obtained at 1000 °C. SEM micrographs of both phosphors have a rounded and filled morphology for individual particles with an approximate diameter of 50-250 nm. Dynamic light scattering studies revealed that average particle size is around 1 ¥ìm for both phosphors.

Effects of Preparation Conditions on Characters of Hydrophobic Silica Granular Aerogel and its Applications

2012 ◽  
Vol 600 ◽  
pp. 190-193 ◽  
Author(s):  
Wei Wei ◽  
Jing Yi Zhang ◽  
Li Ping Wu ◽  
Guo Tong Qin
Keyword(s):  
Particle Size ◽  
Ambient Pressure ◽  
High Surface ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Ambient Pressure Drying ◽  
Average Particle ◽  
Hydrophobic Silica

The hydrophobic silica granular aerogels were synthesized via sol-gel synthesis followed by ambient pressure drying. The tetraethyloxylane (TEOS) was used as original precursor. The aerogels were analyzed using nitrogen adsorption, scanning electron microscopy (SEM) and laser particle size analyzer. It was found that the aerogel was mesoporous material with high surface area. The aerogels were prepared in grain form by dipping into disperse solution in order to adsorption application. The average particle size of the aerogel was controlled by pH and disperse solution volume. The pH also affected gel time. The aerogels were used to absorb phenol from water. The saturated adsorption amount could reach up to 145 mg•g-1.

scholarly journals Preparation, characterization and analysis of zinc oxide nano-particles using a sol-gel technique as an inhibitor for bacteria

2020 ◽  
Vol 11 (1) ◽  
pp. 747-754
Author(s):  
Saja S. Al-Taweel ◽  
Rana S. Al-Taweel ◽  
Hasan M. Luaibi
Keyword(s):  
Zinc Oxide ◽  
Sol Gel ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Nano Particles ◽  
Klebsiella Pneumonia ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Atomic Force

In this work, zinc oxide nanoparticles (ZnO - NPs) were prepared using a sol-gel methodology and tested for their antibacterial activity against each of the following pathogenic species: Escherichia coli, Klebsiella pneumonia, and Staphylococcus aureus by well diffusion assay. The sample prepared was characterized by different techniques: Atomic Force Microscope AFM; Fourier Transform Infrared FT-IR; Scanning Electron Microscope SEM and X-Ray Diffraction Spectroscopy XRD. The XRD result showed that ZnO - NPs presence in wurtzite the structure of ZnO. The AFM and SEM of the surface analysis indicate that the most ZnO – NPs appear approximately in a spherical shape with some agglomeration. The average particle size for  ZnO - NPs is nearly 37 nm. Volumes 25µl, 50µl, 75µl, 100µl, 125µl, and 150µl of 10 mg\ ml concentration of  ZnO - NPs were used, the antimicrobial activity results showed that ability for  ZnO - NPs to inhibit the growth of S.aureus increased as the solution volume increased, while the growing of (K. pneumonia) and (E. coli) was inhibited only with the volume 75µl where the inhibition zones diameters were 15mm and 10mm respectively.

scholarly journals PREPARATION AND STUDY OF FERRITE GARNET R3Fe5O12 (R=Y, Gd, Dy) NANOPARTICLES

2012 ◽  
Vol 15 (2) ◽  
pp. 27-34
Author(s):  
Nguyet Thi Thuy Dao ◽  
Duong Phuc Nguyen ◽  
Hien Duc Than
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Average Particle Size ◽  
Particle Morphology ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Ferrite Garnet ◽  
Transmission Electron ◽  
Scherrer Formula

This paper presents the synthesis and characterization of Y3Fe5O12, Gd3Fe5O12 and Dy3Fe5O12 nanoparticles by sol-gel method using initial salts solution of Y(NO3)3, Gd(NO3)3, Dy(NO3)3, Fe(NO3). The lattice constant, crystallite size and particle morphology of these ferrite garnet nanoparticles were studied by using X-ray diffraction and transmission electron microscopy (TEM). The results showed that the garnet samples prepared by this method were formed at 800oC, which is lower than the sintering temperature for ceramic bulk samples (1400oC). The particle size is in the range 25- 40 nm as observed via TEM image and the average particle size was found to be 37nm using Debye- Scherrer formula.

scholarly journals Fabrication and characterisation of Fe2O3/chitosan aerogel-like spheres

2021 ◽  
Vol 10 (1) ◽  
pp. 74-78
Author(s):  
Nhan Dang Thi Thanh ◽  
Don Truong Thi ◽  
Thang Le Quoc ◽  
Tien Tran Dong ◽  
Son Le Lam
Keyword(s):  
High Surface ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Surface Area ◽  
Hollow Structure ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Sol Gel Process ◽  
High Surface Area Materials

Presently, biopolymer materials have been given more attention for their outstanding properties, high efficiencies and promising applications in various fields. In this study, Fe2O3/chitosan aerogel-like spheres were successfully prepared from chitosan and FeCl3 by sol–gel process and freeze-drying to provide high-surface area materials. The factors affecting the material synthesis have been studied. The asprepared Fe2O3/chitosan material was characterized by Infrared Spectroscopy (IR), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) methods. The results showed that the aerogel spheres have a hollow structure made of chitosan nanofibril networks. Fe2O3 nanoparticles get high crystallinity and have an average particle size of 33 nm.

Sol–gel-based chemical synthesis of NdFeB hard magnetic nanoparticles

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840070 ◽  
Author(s):  
Jinshan Zhang ◽  
Wei Wu ◽  
Fangshi Meng ◽  
Hao Ding ◽  
Jiling Dong
Keyword(s):  
Saturation Magnetization ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Oxide Powders ◽  
Intermediate Phases ◽  
Washing Process ◽  
Oxide Phases

NdFeB nanoparticles were synthesized by a sol–gel method. Firstly, NdFeB gel was prepared by using citric acid and glycol as the gel, and the corresponding salts of Nd, Fe and boric acid. The gel was subsequently annealed under a high temperature condition to obtain NdFeB-oxide phases. Then NdFeB nanoparticles were yielded by reductive annealing of precursors. Microstructure, phase composition and magnetic properties were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM), and also differential scanning calorimetry (DSC) analysis was performed to determine the annealing temperature. At 400[Formula: see text]C, intermediate phases of Fe3BO5 and NdBO3 were formed and stable up to 600[Formula: see text]C; while at 800[Formula: see text]C, they would reacted in presence of oxygen to form NdFeO3 and B2O3. Nd2O3 and Fe2O3 were also formed at this temperature. SEM micrographs of reduced powders after washing process showed an average particle size below 100 nm in all the samples. VSM results showed the oxide powder formed at 800[Formula: see text]C had a coercivity of 1.55 kOe and a saturation magnetization of 1.08 emu/g. The powder synthesized by reduction of oxide powders at 800[Formula: see text]C had a coercivity of 1.02 kOe and a saturation magnetization of 14.17 emu/g.

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