Effect of Mixed-Phase TiO2/PVA Nanofibers on the Degradation on Methyl Orange

2015 ◽  
Vol 1107 ◽  
pp. 353-358
Author(s):  
Norizan Mohammed Lot ◽  
S. Nafisah Md. Rashid ◽  
Umi Sarah Jais ◽  
M. Kamil Abd Rahman
Keyword(s):  
Methyl Orange ◽  
Reaction Rate ◽  
Sol Gel ◽  
Average Diameter ◽  
Mixed Phase ◽  
Electrospinning Technique ◽  
X Ray ◽  
First Order ◽  
Reaction Rate Constants ◽  
Sol Gel Process

We report on the synthesis of nanostructured TiO2for various structural phases and observed the rate of degradation of methyl orange (MO) upon UV irradiation. Mixed phase nanocrystalline TiO2at temperature of 800°C shows higher rate of degradation of MO with the rate of 0.0203/min compared to other phases. This rate corresponds to the percentage of MO degradation of 58.85%, 71.69%, 86.25% and 91.82% for duration of 30, 60, 90 and 120 min of UV irradiations, respectively. The TiO2powder was prepared using titanium (IV) butoxide as the precursor via sol gel process. The samples were characterized using X-ray diffractometer (XRD) and field emission scanning electron microscopy (FESEM). The rate of degradation of MO after UV exposure was measured using UV-Vis spectrophotometer. The first order reaction rate constants (kapp) of anatase; mixed-phase; and rutile phases were 0.0130, 0.0203 and 0.0029, respectively, which shows that mixed-phase TiO2has higherkappvalue indicating higher rate of degradation. The PVA/TiO2nanofibers were produced via electrospinning technique and similar tests on the nanofibers were conducted.Energy dispersive X-ray spectroscopy (EDX) indicates significant presence of TiO2is in nanofibers and the average diameter of the nanofibers was 600 nm.

Enhanced Cr(VI) Removal from Landfill Leachates Using Nanoscale Zero-Valent Iron

2014 ◽  
Vol 905 ◽  
pp. 12-18
Author(s):  
Ting Yi Liu ◽  
Zhong Liang Wang ◽  
Xiao Xing Yan
Keyword(s):  
Citric Acid ◽  
Reaction Rate ◽  
Irreversible Process ◽  
Zero Valent Iron ◽  
Landfill Leachates ◽  
X Ray ◽  
First Order ◽  
Reaction Rate Constants ◽  
Nanoscale Zero Valent Iron ◽  
Pseudo First Order

Nanoscale zero-valent iron modified by citric acid (m-NZVI) was used to remove hexavalent chromium (Cr (VI)) from landfill leachates. Citric acid was useful to enhance the dispersion of NZVI. The results demonstrated that the m-NZVI particles were uniform with a mean diameter of 45.6 nm and the specific surface area was about 22.8 m2/g. The Cr (VI) removal rates increased as an increase of the dosage of m-NZVI and the temperature but decreased as an increase of pH and the initial concentration of HA. Cr (VI) adsorption kinetics followed a pseudo-first-order rate expression and the reaction rate constants ranged from 0.05 to 0.32 min-1. X-ray photoelectron spectroscope (XPS) analysis confirmed that the Fe (III)-critic acid and/or Cr (III)-HA compounds were formed on the m-NZVI surface, which could hinder the formation of Fe (III)-Cr (III) compounds. It was also shown that removing Cr (VI) by m-NZVI was a chemical controlled and irreversible process.

Preparation and Characterization of Pr2Ti2O7 by Sol-Gel Process

2017 ◽  
Vol 748 ◽  
pp. 413-417
Author(s):  
Chun Yu Long ◽  
Fang Fang Peng ◽  
Min Min Jin ◽  
Pei Song Tang ◽  
Hai Feng Chen
Keyword(s):  
Methyl Orange ◽  
Single Phase ◽  
Raw Materials ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Illumination Time ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Using Pr (NO3)3, butyl titanate, ethylene glycol and citric acid as main raw materials, praseodymium titanate (Pr2Ti2O7) was prepared by the sol-gel process. The samples were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), thermal gravity-differential thermal analysis (TG-DTA), diffuse-reflection spectra (DRS) and Fourier transform infrared (FT-IR). The effect of different calcination temperature and illumination time on the photocatalytic properties of Pr2Ti2O7 was investigated. It was found that the single phase Pr2Ti2O7 could be obtained through sol-gel process and calcination at 1000 °C. The Pr2Ti2O7 samples calcination at 1000 °C were uniform , and the resulting product had a particle size of 200 nm and an optical band gap of 3.26 eV. Under ultraviolet light, the degradation of methyl orange arrived to 80.11% after 180 min of photocatalytic reaction. The Pr2Ti2O7 samples showed good photocatalytic activity for decomposition of methyl orange.

scholarly journals Preparation and Characterization of a Calcium Carbonate Aerogel

2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
Johann Plank ◽  
Heinz Hoffmann ◽  
Joachim Schölkopf ◽  
Wolfgang Seidl ◽  
Ingo Zeitler ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Average Diameter ◽  
Supercritical Drying ◽  
Adsorption Method ◽  
X Ray ◽  
Sol Gel Process

We report on a facile method for the preparation of a calcium carbonate aerogel consisting of aggregated secondary vaterite particles with an approximate average diameter of 50 nm. It was synthesized via a sol-gel process by reacting calcium oxide with carbon dioxide in methanol and subsequent supercritical drying of the alcogel with carbon dioxide. The resulting monolith was opaque, brittle and had overall dimensions of  cm. It was characterized by X-ray powder diffraction, nitrogen adsorption method (BET), and scanning electron microscopy.

Fabrication of Li0.06(K0.5,Na0.5)0.94NbO3 Nanofibers by Electrospinning Technique

2019 ◽  
Vol 798 ◽  
pp. 218-222
Author(s):  
Supattra Wongsaenmai ◽  
Tawat Soitong
Keyword(s):  
Calcination Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Structural Phase ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Fiber Morphology ◽  
Electrospinning Technique ◽  
X Ray ◽  
Sol Gel Process

In this work, Li0.06(K0.5,Na0.5)0.94NbO3(KNNL) nanofibers were synthesized by sol–gel process and electrospinning technique. The thermal behaviour ofelectrospun fibers was characterized by thermogravimetric analysis (TG) to obtain the calcination temperature range. The structural phase formation and microstructure were characterized by X-ray diffraction technique (XRD) and scanning electron microscopy (SEM), respectively. The crystal structure was identified by XRD as a single-phase perovskite structure, with orthorhombic symmetry. The microstructure shows that the diameters are in the range of 80–160 nm. The electrospun fibers were calcined from 500°C to 900°C and observed the fiber morphology. With increasing calcination temperature, the fiber diameters decreased until the temperature up to 900 °C the morphology change from cylinder to square or rectangular shape grains.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

scholarly journals PENGARUH RUTE SINTESIS TERHADAP KEEFEKTIFAN PENGIKATAN GUGUS PDETA PADA SINTESIS Fe3O4@SiO2@PDETA

2019 ◽  
Vol 8 (1) ◽  
pp. 39 ◽  
Author(s):  
Susanto Susanto ◽  
Ricka Prasdiantika
Keyword(s):  
Raw Materials ◽  
Sol Gel ◽  
Trisodium Citrate ◽  
Modified Silica ◽  
X Ray ◽  
Dispersion Agent ◽  
Sol Gel Process ◽  
Synthesis Routes ◽  
Mixing Sequences ◽  
Scanning Electron

Synthesis of Fe3O4@SiO2 modified with propyldiethylenetriamine (Fe3O4@SiO2@PDETA) with variation of synthesis routes have been investigated. Research was begun with synthesis of Fe3O4 using dispersion agent of trisodium citrate at coprecipitation system through stirring using ultrasonic wave. Coating magnetite with propyldiethylenetriamine modified silica was carried out through sol-gel process with two different mixing sequences of raw materials (two synthesis routes) with main materials of Fe3O4 synthesized, N-[3-(Trimethoxysilyl)propyl]-diethylenetriamine (TMSPDETA) and Na2SiO3. The products were characterized by fourier transform infrared (FTIR) spectrophotometer and scanning electron microscope-energy dispersive X-ray (SEM-EDX). Results indicate that Fe3O4@SiO2@PDETA has been synthesized succesfully. Fe3O4@SiO2@PDETA synthesized through route 1 (magnetite mixed with a mixture TMSPDETA and Na2SiO3) contains more propyldiethylenetriamine group than that of through route 2 (magnetite mixed with Na2SiO3 solution, then mixed with TMSPDETA)

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