Brookite titania photocatalytic nanomaterials: Synthesis, properties, and applications

2009 ◽  
Vol 81 (12) ◽  
pp. 2407-2415 ◽  
Author(s):  
Jimin Xie ◽  
Xiaomeng Lü ◽  
Jun Liu ◽  
Huoming Shu
Keyword(s):  
Degradation Products ◽  
Photophysical Properties ◽  
X Ray Diffraction ◽  
Synthesis Time ◽  
Photocatalytic Decolorization ◽  
Transmission Electron ◽  
Precursor Phase ◽  
Phase Pure ◽  
Synthesis Properties ◽  
Nanomaterials Synthesis

Phase-pure brookite TiO2 and its activity has been obscured for its difficulty of synthesis. Hence, we introduced the method of preparation and property of phase-pure brookite TiO2 and prepared phase-pure brookite TiO2 by hydrothermal method using Ti(SO4)2 as precursor. Phase formation was achieved by hydrothermal treatment at 180 °C after different synthesis time. The physical and photophysical properties of samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis diffraction (UV–vis/DRS), and Raman spectroscopy. The dependence of the photocatalytic activities on synthesis time and correlations with the physical properties of brookite samples was examined in detail. In the case of mineralization of rhodamine B (Rh B), the sample with the narrowest bandgap and the lowest photoluminescence (PL) intensity (at hydrothermal synthesis time 36 h) showed the best photodecolorization activity. Proposed decolorization mechanism was elucidated in the light of the UV–vis spectra of the analyzed degradation products and frontier electron density (FED) theory. The results indicated that photocatalytic decolorization by brookite TiO2 is a highly effective way to remove Rh B under near-visible light irradiation.

Preparation and Photocatalytic Activity of TiO2/FeOOH Nanocomposite

2012 ◽  
Vol 535-537 ◽  
pp. 219-222
Author(s):  
Dan Chen ◽  
Su Juan Hu ◽  
Guo Hua Li
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Property ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Preparation Temperature ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Phase Pure ◽  
Electron Hole Pair

TiO2/FeOOH nanocomposite was fabricated by a hydrolysis-precipitation approach, using TiCl4 as precursor and FeOOH as support. The crystal phase, diameter and morphology of the sample particle were characterized by X-ray diffraction, transmission electron microscope. The results show that the samples are composed of goethite and rutile. The morphology and diameter of rutile particle, the weight percentages of goethite and rutile, and the microstructure of the samples are related to its preparing temperature and molar ratio of Fe/Ti. The photo-absorption properties of the samples and support were measured by an UV-vis spectroscopy. The results show that the absorption ability of the nanocomposite for visible light is well than that of phase pure rutile. The photocatalytic activity of the nanocomposite as prepared was estimated by degradation of methyl orange (MO) under UV or visible light in an aqueous solution at 303 K. The results indicate that the photocatalytic degradation activity of the nanocomposite for MO is higher than that of phase pure rutile, and the photocatalytic property of the sample is related to its molar ratio of Fe/Ti and preparation temperature. This can be attributed to the microstructure of the nanocomposite, which can improve solar utilization and reduce the recombination rate of solar induced electron-hole pair. This implies that a synergistic effect exists between titania and goethite in the nanocomposite.

Preparation and Photocatalytic Activity of TiO2/Fe2O3 Nanocomposite

2011 ◽  
Vol 130-134 ◽  
pp. 2396-2399
Author(s):  
Su Juan Hu ◽  
Xuan Hui Zhang ◽  
Ying He ◽  
Xian Chao Hu ◽  
Lei Cheng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Synergistic Effect ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Coating ◽  
Transmission Electron ◽  
Phase Pure

TiO2/Fe2O3 nanocomposite was fabricated by a hydrolysis-precipitation approach, with TiCl4 as precursor and Fe2O3 as support. The crystal phase, diameter and morphology of the sample particle were characterized by X-ray diffraction, transmission electron microscope. The results show that the samples are composed of haematite and rutile. The morphology and diameter of rutile particle, coating effect and weight percentages of haematite and rutile are related to the preparing temperature and molar ratio of Fe/Ti. The photocatalytic activity of the prepared photocatalyst was estimated in an aqueous solution at ambient temperature of 303K. The results imply that the photocatalytic activity of the sample is higher than that of phase pure rutile, related to Fe/Ti molar ratio and its preparing temperature. These results can be attribute to the microsturcture of the sample. A synergistic effect exists between titania and haematite in the nanocomposite.

scholarly journals Facile Fabrication of Three-Dimensional Fusiform-Like α-Fe2O3 for Enhanced Photocatalytic Performance

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2650
Author(s):  
Moyan Li ◽  
Hongjin Liu ◽  
Shaozhi Pang ◽  
Pengwei Yan ◽  
Mingyang Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Raw Materials ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Photocatalytic Decolorization ◽  
Transmission Electron ◽  
Facile Fabrication

α-Fe2O3 fusiform nanorods were prepared by a simple hydrothermal method employing the mixture of FeCl3·6H2O and urea as raw materials. The samples were examined by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV–vis diffuse reflectance spectra (UV–DRS). Its visible-light photocatalytic performances were evaluated by photocatalytic decolorization methylene blue (MB) in visible light irradiation. It was found that pure phase α-Fe2O3 nanorods with a length of about 125 nm and a diameter of 50 nm were successfully synthesized. The photocatalytic decolorization of MB results indicated that α-Fe2O3 nanorods showed higher photocatalytic activity than that of commercial Fe2O3 nanoparticles—these are attributed to its unique three-dimensional structure and lower electron-hole recombination rate.

scholarly journals Formation Mechanisms and Phase Stability of Solid-State Grown CsPbI3 Perovskites

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1823
Author(s):  
Jessica Satta ◽  
Alberto Casu ◽  
Daniele Chiriu ◽  
Carlo Maria Carbonaro ◽  
Luigi Stagi ◽  
...  
Keyword(s):  
Solid State ◽  
Secondary Phase ◽  
Phase Evolution ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Synthesis Time ◽  
Time Length ◽  
Transmission Electron ◽  
Δ Phase

CsPbI3 inorganic perovskite is synthesized by a solvent-free, solid-state reaction, and its structural and optical properties can be deeply investigated using a multi-technique approach. X-ray Diffraction (XRD) and Raman measurements, optical absorption, steady-time and time-resolved luminescence, as well as High-Resolution Transmission Electron Microscopy (HRTEM) imaging, were exploited to understand phase evolution as a function of synthesis time length. Nanoparticles with multiple, well-defined crystalline domains of different crystalline phases were observed, usually surrounded by a thin, amorphous/out-of-axis shell. By increasing the synthesis time length, in addition to the pure α phase, which was rapidly converted into the δ phase at room temperature, a secondary phase, Cs4PbI6, was observed, together with the 715 nm-emitting γ phase.

scholarly journals Preparation of Nanostructured Cu2SnS3Photocatalysts by Solvothermal Method

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Qingyun Chen ◽  
Di Ma
Keyword(s):  
Electron Microscopy ◽  
Band Gap ◽  
Solvothermal Method ◽  
Water Solution ◽  
Low Cost ◽  
Photophysical Properties ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Solar Conversion

Nanostructured Cu-Sn-S powder was prepared by a relatively low-cost, simple, and green solvothermal method. Flower-like Cu2SnS3nanostructures were successfully synthesized in 50 vol% ethanol water solution at 200 °C for 7.5 h. The structure and photophysical properties of the as-obtained samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and UV-Vis diffusion reflectance spectroscopy. Results showed that the cubic and tetragonal Cu2SnS3was obtained by varying the ethanol contents. The band-gap energy of tetragonal Cu2SnS3nanocrystals is near the optimum for photovoltaic solar conversion in a single band-gap device.

A NEW METHOD TO PREPARE THE NOVEL ANATASE TiO2

2008 ◽  
Vol 15 (04) ◽  
pp. 509-513 ◽  
Author(s):  
GUANJUN CUI ◽  
ZHANXIA XU ◽  
YAN WANG ◽  
MIN ZHANG ◽  
JIANJUN YANG
Keyword(s):  
Oxygen Vacancies ◽  
High Photocatalytic Activity ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Decolorization ◽  
Transmission Electron ◽  
Light Region ◽  
Spin Resonance ◽  
Blue Solution

In this paper, a kind of novel anatase TiO 2 nanoparticle with single-electron-trapped oxygen vacancies was prepared by hydrothermal treated nanotube titanic acid. The morphology, structure, and properties of the products were characterized by transmission electron microscope, X-ray diffraction, electron spin resonance, and photoluminescence. Photocatalytic decolorization of the Methylene Blue solution was carried out in the visible light region and showed a high photocatalytic activity.

scholarly journals Synthesis, Characterization, and Photocatalysis of Well-Dispersible Phase-Pure Anatase TiO2Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xiuzhen Wei ◽  
Guangfeng Zhu ◽  
Jinfeng Fang ◽  
Jinyuan Chen
Keyword(s):  
Average Particle Size ◽  
Xrd Analysis ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Present Sample ◽  
Prepared Sample ◽  
Transmission Electron ◽  
Bet Analysis ◽  
Photocatalytic Activities ◽  
Phase Pure

High-purity anatase TiO2nanoparticles were prepared using an improved sol-hydrothermal method. The as-prepared sample was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and UV-vis diffuse reflectance spectra. TEM results showed that the average particle size of all TiO2particles was calculated to be (10±1) nm. The XRD analysis indicated that the present sample was fully crystallized and appeared to be highly phase-pure anatase. The BET analysis showed that the as-prepared sample had a very large specific surface area of 186.25 m2/g. The photocatalytic performance of TiO2nanoparticles was evaluated by photocatalytic degradation of X-3B and X-BR solutions. The degradation results revealed that the as-prepared TiO2showed slightly higher photocatalytic activities than P25. Whereas, the as-synthesized TiO2can settle down and be separated easily after the photocatalytic reaction finishes.

scholarly journals Effect of Preparation Parameters on Photoactivity of BiVO4by Hydrothermal Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Qingyun Chen ◽  
Miao Zhou ◽  
Di Ma ◽  
Dengwei Jing
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Photophysical Properties ◽  
Catalytic Performance ◽  
Mixed Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Orthogonal Experiments ◽  
Transmission Electron ◽  
Experimental Parameters

Bismuth vanadate (BiVO4) was synthesized from a mixture of aqueous Bi(NO3)3and NH4VO3solutions by using hydrothermal method. Via conducting the orthogonal experiments and single-factor experiments, the best synthetic parameters were determined. The physical and photophysical properties of the as-obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-Vis diffusion reflectance spectroscopy (UV-Vis). The result showed that the best experimental parameters of monoclinic BiVO4werepH=7,T=195 °C, and  t=6 h. The catalytic performance of BiVO4was evaluated by reducing carbon dioxide to methane under visible light irradiation. It was found that the methane production reached 145 μg/g-cat after 5 h irradiation with the catalyst dosage of 0.15 g in 200 mL mixed solution of 0.1 M NaOH and 0.1 M Na2SO3.

scholarly journals Fabrication and Photocatalytic Properties of ZnSe Nanorod Films

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jiajia Yin ◽  
Chao Yang ◽  
Xianheng Yang ◽  
Shutong Wang ◽  
Hua Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photophysical Properties ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Environmentally Safe ◽  
Synthesis Protocol ◽  
Dye Solutions

ZnSe nanorod films grown on fused quartz glass substrates via a simple two-step synthesis protocol were demonstrated to be environmentally safe and effective recyclable photocatalysts. These films showed greatly enhanced photocatalytic activity compared to pulsed laser deposition ZnSe films in the degradation of methyl orange dye solutions. The well-crystalized ZnSe nanorods had a length of 15 µm and a diameter of 200 nm and were densely grown on the substrate. The morphology, crystal structure, crystal phase, and photophysical properties of the ZnSe nanorod films were investigated using field-emission scanning electron microscopy (FE-SEM), UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM).

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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