Synthesis, characterization and photocatalytic activity of 1D TiO2 nanostructures

2014 ◽  
Vol 70 (6) ◽  
pp. 972-979 ◽  
Author(s):  
Julieta Cabrera ◽  
Hugo Alarcón ◽  
Alcides López ◽  
Roberto Candal ◽  
Dwight Acosta ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Surface Area ◽  
Sol Gel ◽  
One Dimensional ◽  
Tio2 Anatase ◽  
1D Nanostructures ◽  
Sol Gel Process ◽  
Tio2 Nanopowders ◽  
The One ◽  
Tio2 Nanostructures

Nanowire/nanorod TiO2 structures of approximately 8 nm in diameter and around 1,000 nm long were synthesized by alkaline hydrothermal treatment of two different TiO2 nanopowders. The first precursor was TiO2 obtained by the sol-gel process (SG-TiO2); the second was the well-known commercial TiO2 P-25 (P25-TiO2). Anatase-like 1D TiO2 nanostructures were obtained in both cases. The one-dimensional (1D) nanostructures synthesized from SG-TiO2 powders turned into rod-like nanostructures after annealing at 400 °C for 2 h. Conversely, the nanostructures synthesized from P25-TiO2 preserved the tubular structure after annealing, displaying a higher Brunauer–Emmett–Teller surface area than the first system (279 and 97 m2/g, respectively). Despite the higher surface area shown by the 1D nanostructures, in both cases the photocatalytic activity was lower than for the P25-TiO2 powder. However, the rod-like nanostructures obtained from SG-TiO2 displayed slightly higher efficiency than the sol-gel prepared powders. The lower photocatalytic activity of the nanostructures with respect to P-25 can be associated with the lower crystallinity of 1D TiO2 in both materials.

scholarly journals 1D TiO2 Nanostructures Prepared from Seeds Presenting Tailored TiO2 Crystalline Phases and Their Photocatalytic Activity for Escherichia coli in Water

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Julieta Cabrera ◽  
Dwight Acosta ◽  
Alcides López ◽  
Roberto J. Candal ◽  
Claudia Marchi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Photocatalytic Activity ◽  
Bactericidal Activity ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
E Coli ◽  
1D Nanostructures ◽  
Sol Gel Synthesis ◽  
Hydrolysis Of ◽  
Tio2 Nanostructures

TiO2 nanotubes were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles with a controlled proportion of anatase and rutile. Tailoring of TiO2 phases was achieved by adjusting the pH and type of acid used in the hydrolysis of titanium isopropoxide (first step in the sol-gel synthesis). The anatase proportion in the precursor nanoparticles was in the 3–100% range. Tube-like nanostructures were obtained with an anatase percentage of 18 or higher while flake-like shapes were obtained when rutile was dominant in the seed. After annealing at 400°C for 2 h, a fraction of nanotubes was conserved in all the samples but, depending on the anatase/rutile ratio in the starting material, spherical and rod-shaped structures were also observed. The photocatalytic activity of 1D nanostructures was evaluated by measuring the deactivation of E. coli in stirred water in the dark and under UV-A/B irradiation. Results show that in addition to the bactericidal activity of TiO2 under UV-A illumination, under dark conditions, the decrease in bacteria viability is ascribed to mechanical stress due to stirring.

Visible-Light Driven BiFeO3 Nanosized Photocatalysts Prepared by a Sol-Gel Process

2011 ◽  
Vol 110-116 ◽  
pp. 1912-1917 ◽  
Author(s):  
Pei Song Tang ◽  
Hai Feng Chen ◽  
Feng Cao ◽  
Guo Xiang Pan ◽  
Min Hong Xu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Band Gap ◽  
Surface Area ◽  
Narrow Band ◽  
Sol Gel ◽  
Large Specific Surface Area ◽  
Sol Gel Process ◽  
Visible Light Photocatalytic

The single perovskite BiFeO3 nanoparticles were prepared by a sol-gel process. The BiFeO3 nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy, and Brunauer-Emmett-Teller (BET) method. It was found that the prepared BiFeO3 nanoparticles show the large specific surface area of 136 m2/g, and narrow band gap of 2.12 eV. Consequently, BiFeO3 nanoparticles show high visible-light photocatalytic activity for decomposition of methylene blue in comparison with the commercial Degussa P25. It is concluded that the large specific surface area and the narrow band gap contribute to the high visible-light photocatalytic activity through enhanced adsorption capability and visible-light absorption.

Photocatalytic Properties of the Transition Metal Doped TiO2 Powder Prepared by Sol-Gel Process

2007 ◽  
Vol 280-283 ◽  
pp. 647-650 ◽  
Author(s):  
Chin Myung Whang ◽  
J.G. Kim ◽  
Hae Jin Hwang
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metal ◽  
Surface Area ◽  
Sol Gel ◽  
Doped Tio2 ◽  
X Ray ◽  
Undoped Tio2 ◽  
Sol Gel Process ◽  
Uv Visible ◽  
Metal Doped

Transition metal-doped TiO2 powders as a photocatalyst were prepared by sol-gel process and Sb, Bi and Nb were introduced into them as dopants. The photocatalytic behaviors of the doped TiO2 powder were studied as a function of dopant, doping concentration and preparation conditions. X-ray diffraction, FT-Raman, B.E.T. and scanning electron microscopy were applied for structural and microstructural studies. Optical properties of the doped TiO2 powders were studied by UV-Visible Spectrometer and photocatalytic activity of the doped TiO2 was characterized in terms of the degradation of 1,4-dichlorobenzene. X-ray difraction analysis showed that doping with a transition metal ion suppresses anatase-to-rutile phase transition compared with the pure TiO2. The Sb and Nb-doped TiO2 powders did not exhibit any other diffraction peaks except those belonging to TiO2. On the other hand, a diffraction peak of Bi4Ti3O12 appears for 5 at.% Bi-doped samples. All of the doped TiO2 powders had higher specific surface area than undoped TiO2. Surface area increased with increasing dopant concentration depending on the dopant, from 33.9 m2/g to 55.4m2/g. The UV-visible absorption spectra of doped samples were red-shifted by 20~50nm according to the doping level. Also transition metal doped TiO2 powders exhibited better photocatalytic activity than the undoped TiO2. The increase in photoactivity is probably due to the increase in the interfacial electron transfer, red shifts, and better crystallinity.

Ultrahigh Surface Area Nanoporous Silica Particles via an Aero-Sol−Gel Process

Langmuir ◽  
2004 ◽  
Vol 20 (7) ◽  
pp. 2523-2526 ◽  
Author(s):  
S. H. Kim ◽  
B. Y. H. Liu ◽  
M. R. Zachariah
Keyword(s):  
Surface Area ◽  
Sol Gel ◽  
Silica Particles ◽  
Nanoporous Silica ◽  
Sol Gel Process

The Preparation and Photocatalytic Activity of SWNTs Doped ZnO/TiO2 Compound Films

2010 ◽  
Vol 97-101 ◽  
pp. 1611-1615 ◽  
Author(s):  
Qing Wang ◽  
Xin Li Li ◽  
Wei Nie ◽  
Yong Mei Xia ◽  
Jian Feng Dai
Keyword(s):  
Photocatalytic Activity ◽  
Absorption Spectra ◽  
Sol Gel ◽  
Composite Films ◽  
Wavelength Region ◽  
Tio2 Films ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Doped Zno ◽  
Walled Carbon Nanotubes

The ZnO/TiO2 composite films were deposited over glass using spin coating technique by sol-gel process. Single-walled carbon nanotubes (SWNTs) were used to modify the ZnO/TiO2 films successfully in this paper. The structure and composition of the ZnO/TiO2 composite and SWNTs doped ZnO/TiO2 composite were characterized by X-ray diffraction (XRD). The morphology of samples was characterized by scanning electron microscopy (SEM). The photocatalytic activity was investigated by photocatalytic degradation of aqueous methyl orange under ultraviolet (UV) radiation. The UV-vis absorption spectra of the ZnO/TiO2 films and SWNTs doped ZnO/TiO2 films in the wavelength region 200~800 nm were obtained. The results indicate that the SWNTs addition can decrease the grain size of ZnO/TiO2, which can enhance the photocatalytic activity. UV-vis absorption spectra of SWNTs-ZnO/TiO2 showed obvious blue shifts compared with ZnO/TiO2. The optimal amount of doping SWNTs is 1% according to this research. The enhanced mechanism of the SWNTs for the photocatalytic activity in ZnO/TiO2 films was analyzed in this article.

Texture Evaluation of Sol-Gel Derived Mesoporous Bioactive Glass

2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih
Keyword(s):  
Surface Area ◽  
Calcination Temperature ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Bioactive Glasses ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Adsorption Desorption

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.

Experimental Research on Degradation of Azo Dye Wasterwater by Photocatalysis of Nano-TiO2 Doped with Ce / Fe

2013 ◽  
Vol 295-298 ◽  
pp. 331-334 ◽  
Author(s):  
Hong Jiao Song ◽  
Lei Zhu ◽  
Xun Wang
Keyword(s):  
Photocatalytic Activity ◽  
Experimental Research ◽  
Azo Dye ◽  
Sol Gel ◽  
Dye Wastewater ◽  
Photogenerated Electrons ◽  
Sol Gel Process ◽  
Degradation Of Azo Dye

The sol-gel process is applied to respectively prepare nano-TiO2films with Ce (cerium) or nano-TiO2films with Fe (ferium), which are used to degradate azo dye wastewater and present their characterization by XRD and HRTEM methods. The results show that proper amount of Ce or Fe doped into the nano-TiO2films can effectively accelerate the separation of photogenerated electrons-holes and easily form lattices, and consequently promotes nano-TiO2films' photocatalytic activity by nearly 20%.

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.

Sol-gel synthesis, characterisation, and photocatalytic activity of porous spinel Co3O4 nanosheets

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Uv Light ◽  
Average Pore Size ◽  
Sol Gel ◽  
Spherical Particles ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Oriented Growth

AbstractMesoporous spinel Co3O4 nanosheets were synthesised via a simple sol-gel route using the Pluronic P123 triblock copolymer as the stabilising agent. Their structural, morphological, and textural properties were characterised. FTIR spectrum revealed the formation of cobalt oxide without any surface adsorbed impurities. Face centered cubic phase of spinel Co3O4 with the mean crystalline size of 26 nm was assigned by the X-ray diffraction analysis without the formation of other phases. Porous nanosheets and cave-like morphologies were identified from the scanning electron microscopy (SEM) images. Highly agglomerated more or less spherical particles with well separated lattice fringes, representing the oriented growth of nanocrystals, were noticed on the transmission electron microscopy photographs. Surface area analysis revealed that the spinel has high surface area of about 25 m2 g−1 with monomodal mesoporosity. The average pore size distribution was found to be about 15.8 nm. The as-prepared spinel photocatalyst showed a mild photocatalytic activity in the degradation of methylene blue (2.5 mg L−1) under UV light irradiation with air as the oxidising agent. Photocatalytic activity of the as-prepared reusable Co3O4 was found to be higher than that of the commercial spinel powder.

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