scholarly journals bcl Morphology Formation Strategy on Nanostructured Titania via Alkaline Hydrothermal Treatment

2019 ◽  
Vol 14 (3) ◽  
pp. 513 ◽  
Author(s):  
Fry Voni Steky ◽  
Veinardi Suendo ◽  
Rino Rakhmata Mukti ◽  
Didi Prasetyo Benu ◽  
Muhammad Reza ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Open Channel ◽  
Particle Surface ◽  
Phase Segregation ◽  
Tio2 Particle ◽  
Hydrothermal Route ◽  
Tio2 Particles ◽  
Segregation Process ◽  
General Pathway ◽  
Nanostructured Titania

Titanium dioxide (TiO2) is a semiconductor material that plays an important role in photocatalysis. Bicontinuous concentric lamellar (bcl) is an interesting morphology with an open channel pore structure that has been successfully synthesized on silica-based materials. If bcl morphology can be applied in TiO2 system, then many surface properties of TiO2 can be enhanced, i.e. photocatalytic activity. A simple and effective strategy has been demonstrated to transform aggregated and spherical TiO2 particles to bcl morphology via alkaline hydrothermal route. Alkaline hydrothermal treatment successfully transforms TiO2 particle surface to have bcl morphology through swelling with ammonia then followed by phase segregation process. We proposed this strategy as a general pathway to transform the particle surface with any shape to have bcl morphology. Copyright © 2019 BCREC Group. All rights reserved 

scholarly journals The Effect of NaOH and KOH on the Characterization of Mesoporous AlOOH Nanostructures in the Hydrothermal Route

2017 ◽  
Vol 58 (2) ◽  
Author(s):  
Nahid Haghnazari ◽  
Mozaffar Abdollahifar ◽  
Farahnaz Jahani
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Hydrothermal Treatment ◽  
Specific Surface Area ◽  
Analytical Techniques ◽  
Aluminium Nitrate ◽  
Hydrothermal Route ◽  
Bet Specific Surface Area ◽  
Adsorption Desorption

Mesoporous AlOOH was synthesized by hydrothermal treatment from aluminium nitrate and NaOH or KOH. The effect of NaOH and KOH as precipitating agents on the characterization of samples were investigated. xrd, ftir, fesem and N<sub>2</sub> adsorption-desorption analytical techniques were used to characterize the products. Our results showed that using KOH as precipitating agent was favourable for the formation of mesoporous and crystalline AlOOH with high bet-specific surface area of 98 m<sup>2</sup>/g.

The Effect of Double-Element Doping on the Photocatalytic Property of Nano-TiO2

2013 ◽  
Vol 669 ◽  
pp. 371-376
Author(s):  
Su Huang ◽  
Fu Yun Li ◽  
Yang Li ◽  
Li Zhen Yang
Keyword(s):  
Methyl Orange ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Tio2 Particle ◽  
Metallic Elements ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Minimum Diameter ◽  
Tio2 Particles ◽  
Element Doping

Sol-gel method was applied to synthesize nano-TiO2 particles doped with metal and non-metallic elements. Nano-TiO2 particles were doped at different calcinations’ temperatures with S and Fe, Ce and La, respectively. A comparison was performed on the effect of different metallic elements on nano-TiO2 particles doped with the same non-metallic element S. X-ray diffraction results indicated that the diameter of doped nano-TiO2 particle was smaller than that of non-doped nano-TiO2 particles. The minimum diameter of nano-TiO2 doped with Ce and S was about 8nm, while that of nano-TiO2 doped with La and S was about 9nm. The minimum diameter of nano-TiO2 particles doped with Fe and S was about 10nm. In addition, with the increase of calcinations’ temperature, the size of nano-TiO2 particle increased. All nano-TiO2 particles doped with double elements were antae. Methyl orange was used to simulate the pollutant to analyze the photocatalytic property of doped nano-TiO2. The results indicated that the doped element had some effect on the photocatalytic property of nano-TiO2, and varied for different doped metallic elements. Among them, the degradation rate of methyl orange by nano-TiO2 doped with La and S under the calcinations’ temperature of 550 °C reached 28.97%.

Synthesis of sub-micrometric SAPO-34 by a morpholine assisted two-step hydrothermal route and its excellent MTO catalytic performance

2019 ◽  
Vol 48 (8) ◽  
pp. 2606-2616 ◽  
Author(s):  
Syed ul Hasnain Bakhtiar ◽  
Sher Ali ◽  
Xiaotong Wang ◽  
Fulong Yuan ◽  
Zhibin Li ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Crystal Size ◽  
Cost Effective ◽  
Catalytic Performance ◽  
Hydrothermal Route ◽  
Light Olefin ◽  
Structure Directing Agent ◽  
Olefin Selectivity

SAPO-34 with a sub-micrometer crystal size was synthesized by a double hydrothermal treatment employing cost-effective morpholine as a structure directing agent, which presented an enhanced catalytic lifetime (nearly 3 times the conventional one) in the reaction of methanol to olefins with a higher light olefin selectivity (total selectivity of 97.1%).

An ionic liquid promoted microwave-hydrothermal route towards highly photoluminescent carbon dots for sensitive and selective detection of iron(iii)

RSC Advances ◽  
2015 ◽  
Vol 5 (31) ◽  
pp. 24205-24209 ◽  
Author(s):  
Ruili Liu ◽  
Mengping Gao ◽  
Jing Zhang ◽  
Zhilian Li ◽  
Jinyang Chen ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Hydrothermal Treatment ◽  
Rice Straw ◽  
Carbon Dots ◽  
Selective Detection ◽  
Hydrothermal Route ◽  
Microwave Hydrothermal ◽  
Photoluminescence Efficiency

Carbon dots with a high photoluminescence efficiency of ∼22.58% are obtained by a facile microwave-hydrothermal treatment of rice straw with the presence of ionic liquid.

Thin-Film Cadmium Sulfide/Cadmium Telluride Alloys

1996 ◽  
Vol 426 ◽  
Author(s):  
D. G. Jensen ◽  
B. E. McCandless ◽  
R. W. Birkmire
Keyword(s):  
Heat Treatment ◽  
Equilibrium Phase ◽  
Phase Segregation ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Parameter Determination ◽  
Miscibility Gap ◽  
X Ray Diffraction ◽  
Segregation Process ◽  
Two Phases

AbstractThin films of CdTel-xSx with bulk atomic compositions, x≡[S]/([S]+[Te]), ranging from 0 to 0.45 were deposited by vacuum co-evaporation of CdTe and CdS with substrate temperatures of 200 and 250°C. X-ray diffraction analysis revealed that films with x < 0.3 were predominately single phase having the zincblende structure. Films with 0.35 < x < 0.45 contained the wurtzite modification. Lattice parameter determination indicated that each phase exists with compositions well within the miscibility gap shown on published equilibrium phase diagrams. The variation of the optical band gap with x was determined by measuring transmission and reflection of the films. Heat treatment at 415°C in the presence of CdC12 caused the films to segregate into two phases consistent with the phase diagram. If the CdCl2 is assumed to only promote the phase segregation process, then the compositions of the two phases after heat treatment may be taken as measurements of the solubility limits of S in CdTe and Te in CdS respectively. The solubility limit of S in CdTe was thus determined to be 5.8% at 415°C which is the temperature used for the common CdC12 treatment of CdTe-based solar cells. An analysis of CdTe/CdS solar cell device structures shows that the atomic composition of alloys created by interdiffusion are consistent with these solubility limits.

Fabrication and Evaluation of Arrayed Needle-Like TiO2 Particle – Transparent Resin Composite Films

2011 ◽  
Vol 484 ◽  
pp. 177-182
Author(s):  
Shin Ichi Kikitsu ◽  
Takaaki Otsuka ◽  
Hidetoshi Miyazaki ◽  
Hisao Suzuki ◽  
Toshitaka Ota
Keyword(s):  
Composite Film ◽  
Resin Composite ◽  
Composite Films ◽  
Tio2 Particle ◽  
Mixing Ratio ◽  
Tio2 Particles ◽  
Fabrication Condition

Needle-like TiO2-resin composite films were fabricated using needle-like TiO2 particle filler and urethane matrix. The needle-like TiO2 particles in the composite film were arrayed completely under the fabrication condition of applying AC bias of 10 volt with 0.1 Hz for 4 hr, and the transmittance of the resulting composite film showed angularly dependence. The needle-like TiO2 particles in the composite were oriented quickly by a larger applying bias. Furthermore, increase of the mixing ratio of TiO2 particles in the composite film caused increasing an angularly dependence of the transmittance of the composites.

scholarly journals Preparation of TiO2 Nanoparticle Aggregates and Capsules by the ‘Two-Emulsion Method’

2020 ◽  
Vol 4 (4) ◽  
pp. 57
Author(s):  
Nadya I. Politova-Brinkova ◽  
Sonya R. Tsibranska-Gyoreva ◽  
Slavka S. Tcholakova ◽  
Nikolai D. Denkov ◽  
Thomas Danner
Keyword(s):  
Practical Interest ◽  
Tio2 Particle ◽  
Oil Viscosity ◽  
Emulsion Method ◽  
Tio2 Particles ◽  
Nanoparticle Aggregates ◽  
Water Drops ◽  
Great Practical Interest ◽  
Oil Emulsions ◽  
Micrometer Size

TiO2-based materials are of great practical interest in several technological areas. Both the size and the morphology of the TiO2 particles are of critical importance for their applications. The current study explores the effect of several factors on the outcome of the TiO2 particle synthesis via the so-called ‘two-emulsion method’. In this technique, two water-in-oil emulsions—each of them containing different reactant in the dispersed water drops—are mixed under well controlled conditions. Upon such mixing, partial coalescence of the water drops from the two emulsions leads to mixing of the drop content, with chemical reaction occurring within the drops, and to synthesis of Ti(OH)4 particles. Afterwards, the latter are transformed by emulsion heating into TiO2 particles and aggregates of predominantly anatase structure. Our results show that—depending on the precursor and surfactant concentrations, oil viscosity, emulsification time, and mixing speed—the obtained nanoparticles could aggregate either on the drop surface, forming capsules with a very smooth surface, or inside the water droplets, thus leading to hierarchically structured aggregates of micrometer size. The spherical smooth capsules are constructed of very small monodisperse TiO2 nanoparticles with size below 5 nm. The hierarchical bulk aggregates, on the other hand, are formed from bigger primary particles of sub-micrometer size. The obtained results show that one can obtain various TiO2 structures by controlling the conditions during the emulsion preparation and mixing

Preparation and Characterization of Glass Flake/Nano-TiO2 Compound Particle on Low Temperature

2012 ◽  
Vol 490-495 ◽  
pp. 3362-3365
Author(s):  
Yi Guo ◽  
Jun Yan ◽  
Shi Guo Du ◽  
Bin Wang ◽  
Jia Liu
Keyword(s):  
Low Temperature ◽  
Composite Particle ◽  
Film Formation ◽  
Tio2 Particle ◽  
Growth Speed ◽  
Tio2 Particles ◽  
Glass Flake ◽  
Compound Particle ◽  
Main Material

Glass flake has excellent capacity of anti-infiltration, for perfecting the bonding of resin and glass flake, Using butyl titanate as the main material, the glass flake/TiO2 composite particle doped by Sn4+ at low temperature was prepared. SEM observation indicated that TiO2 particles covered the glass flake powder surface and form nanometer/micron structure. XRD showed TiO2 particle was amorphous, the particle size was very small or just formed halfcrystal. Acidity effected the growth speed of crystal and structure of growth elementary. SnCl4 could form heterogeneous crystal to lead the TiO2 film formation.

scholarly journals Stochastic phase segregation on surfaces

2017 ◽  
Vol 4 (8) ◽  
pp. 170472 ◽  
Author(s):  
Prerna Gera ◽  
David Salac
Keyword(s):  
Growth Rate ◽  
Statistical Analysis ◽  
Phase Segregation ◽  
Thermal Fluctuations ◽  
Stochastic Noise ◽  
Chemical Systems ◽  
Segregation Process ◽  
Physical And Chemical ◽  
Influence Of Noise ◽  
Spherical Interface

Phase separation and coarsening is a phenomenon commonly seen in binary physical and chemical systems that occur in nature. Often, thermal fluctuations, modelled as stochastic noise, are present in the system and the phase segregation process occurs on a surface. In this work, the segregation process is modelled via the Cahn–Hilliard–Cook model, which is a fourth-order parabolic stochastic system. Coarsening is analysed on two sample surfaces: a unit sphere and a dumbbell. On both surfaces, a statistical analysis of the growth rate is performed, and the influence of noise level and mobility is also investigated. For the spherical interface, it is also shown that a lognormal distribution fits the growth rate well.

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