Facile Sol-Gel Synthesis of Mesoporous TiO2 in Ionic Liquids

2013 ◽  
Vol 389 ◽  
pp. 53-56
Author(s):  
Shu Guo ◽  
Sheng Xu Lu ◽  
Hui Ding ◽  
Zai Feng Shi

The mesoporous TiO2 particles was conveniently prepared in a room temperature ionic liquid (RTILs) of 1, 3-di-(3-propionyloxy) imdazolium tetrafluoroborate [DiprCOOBF4 system. The obtained materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorptiondesorption analysis. XRD patterns revealed that only rutile phase is formed in the RTILs. The TEM micrographs as well as N2 adsorptiondesorption measurements show that the prepared products exhibited wormlike pore structures. The FTIR (Fourier Transform Infrared Spectra) demonstrate the carboxylate groups attach via bidentate or bridging coordination to the TiO2 surface.

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sanja Ćulubrk ◽  
Željka Antić ◽  
Vesna Lojpur ◽  
Milena Marinović-Cincović ◽  
Miroslav D. Dramićanin

Herein we presented hydrolytic sol-gel synthesis and photoluminescent properties of Eu3+-doped Gd2Ti2O7pyrochlore nanopowders. According to Gd2Ti2O7precursor gel thermal analysis a temperature of 840°C is identified for the formation of the crystalline pyrochlore phase. Obtained samples were systematically characterized by powder X-ray diffraction, scanning and transmission electron microscopy, and photoluminescence spectroscopy. The powders consist of well-crystalline cubic nanocrystallites of approximately 20 nm in size as evidenced from X-ray diffraction. The scanning and transmission electron microscopy shows that investigated Eu3+-doped Gd2Ti2O7nanopowders consist of compact, dense aggregates composed entirely of nanoparticles with variable both shape and dimension. The influence of Eu3+ions concentration on the optical properties, namely, photoluminescence emission and decay time, is measured and discussed. Emission intensity as a function of Eu3+ions concentration shows that Gd2Ti2O7host can accept Eu3+ions in concentrations up to 10 at.%. On the other hand, lifetime values are similar up to 3 at.% (~2.7 ms) and experience decrease at higher concentrations (2.4 ms for 10 at.% Eu3+). Moreover, photoluminescent spectra and lifetime values clearly revealed presence of structural defects in sol-gel derived materials proposing photoluminescent spectroscopy as a sensitive tool for monitoring structural changes in both steady state and lifetime domains.


2004 ◽  
Vol 848 ◽  
Author(s):  
Lidia Armelao ◽  
Davide Barreca ◽  
Gregorio Bottaro ◽  
Andrea Caneschi ◽  
Claudio Sangregorio ◽  
...  

ABSTRACTThis work is focused on the sol-gel synthesis of pure and Ca-doped LaCoO3 nanopowders. The samples were prepared starting from methanolic solutions of cobalt (II) acetate (Co(CH3COO)2·4H2O), lanthanum (III) nitrate (La(NO3)3·6H2O) and calcium (II) acetate (Ca(CH3COO)2·H2O). After solvent evaporation, the obtained powders were dried under vacuum and subsequently treated in air up to 1273 K. The system evolution under thermal annealing was studied by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), while the chemical composition was analyzed by X-ray Photoelectron (XPS) and X-ray Excited Auger electron (XE-AES) spectroscopies. The temperature and field dependence of the magnetic properties of the Ca-doped samples were investigated, and compared to those of the corresponding pure LaCoO3 powders.


2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.


2005 ◽  
Vol 20 (3) ◽  
pp. 563-566 ◽  
Author(s):  
Tetsuji Saito ◽  
Hiroyuku Takeishi ◽  
Noboru Nakayama

We report a new compression shearing method for the production of bulk amorphous materials. In this study, amorphous Nd–Fe–B melt-spun ribbons were successfully consolidated into bulk form at room temperature by the compression shearing method. X-ray diffraction and transmission electron microscopy studies revealed that the amorphous structure was well maintained in the bulk materials. The resultant bulk materials exhibited the same magnetic properties as the original amorphous Nd–Fe–B materials.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Aidong Tang ◽  
Yuehua Deng ◽  
Jiao Jin ◽  
Huaming Yang

A novel nanocomposite ZnFe2O4-TiO2/MCM-41 (ZTM) was synthesized by a sol-gel method and characterized through X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N2adsorption-desorption, Raman spectroscopy, and ultraviolet visible (UV-vis) spectrophotometry. The results confirmed the incorporation of ZnFe2O4-TiO2nanoparticles inside the pores of the mesoporous MCM-41 host without destroying its integrity. ZnFe2O4nanoparticles can inhibit the transformation of anatase into rutile phase of TiO2. Incorporation of ZnFe2O4-TiO2within MCM-41 avoided the agglomeration of nanoparticles and reduced the band gap energy of TiO2to enhance its visible light photocatalytic activity. UV-vis absorption edges of ZTM nanocomposites redshifted with the increase of Zn/Ti molar ratio. The nanocomposite approach could be a potential choice for enhancing the photoactivity of TiO2, indicating an interesting application in the photodegradation and photoelectric fields.


1999 ◽  
Vol 562 ◽  
Author(s):  
Michelle Chen ◽  
Suraj Rengarajan ◽  
Peter Hey ◽  
Yezdi Dordi ◽  
Hong Zhang ◽  
...  

ABSTRACTSelf-annealing properties of electroplated and sputtered copper films at room temperature were investigated in this study, in particular, the effect of copper film thickness, electrolyte systems used, as well as their level of organic additives for electroplating. Real-time grain growth was observed by transmission electron microscopy. Sheet resistance and X-ray diffraction measurements further confirmed the recrystallization of the electroplated copper film with time. The recrystallization of electroplated films was then compared with that of sputtered copper films.


2019 ◽  
Vol 9 (22) ◽  
pp. 4878 ◽  
Author(s):  
Jae-Hun Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Hong Joo Kim ◽  
Phan Quoc Vuong ◽  
...  

X-Ray radiation sensors that work at room temperature are in demand. In this study, a novel, low-cost real-time X-ray radiation sensor based on SnO2 nanowires (NWs) was designed and tested. Networked SnO2 NWs were produced via the vapor–liquid–solid technique. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM) analyses were used to explore the crystallinity and morphology of synthesized SnO2 NWs. The fabricated sensor was exposed to X-rays (80 kV, 0.0–2.00 mA) and the leakage current variations were recorded at room temperature. The SnO2 NWs sensor showed a high and relatively linear response with respect to the X-ray intensity. The X-ray sensing results show the potential of networked SnO2 NWs as novel X-ray sensors.


2016 ◽  
Vol 5 (4) ◽  
pp. 196
Author(s):  
R. Palomino-Merino ◽  
R. Lozada-Morales ◽  
J. Martínez-Juárez ◽  
G. Juárez-Díaz ◽  
J. Carmona-Rodriguez ◽  
...  

Nanocrystalline Er-doped TiO2 was prepared by sol-gel at room temperature. X-ray diffraction, photoacoustic spectroscopy (optical absorption), transmission electron microscopy (TEM), and electron dispersion microscopy (EDS) were carried out on both as-prepared and thermally-annealed (air at 700 ºC) samples, revealing the anatase crystalline phase of TiO2. The samples exhibit an average grain size from 38 to 5.1 nm, as the nominal concentration of Er varies from 0 % to 7 %. The photoacoustic spectra evidence the absorption edge at 300 nm attributed to TiO2, as well as several electronic transitions which are atomic energy absorption-line levels characteristics of Er.


2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.


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