scholarly journals Black Titanium Dioxide Nanomaterials in Photocatalysis

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Xiaodong Yan ◽  
Yong Li ◽  
Ting Xia
Keyword(s):  
Titanium Dioxide ◽  
Visible Spectrum ◽  
Photocatalytic Efficiency ◽  
Structure Property ◽  
Preparation Methods ◽  
Practical Applications ◽  
Optical And Electronic Properties ◽  
Amorphous Surface ◽  
Structure Engineering ◽  
Black Color

Titanium dioxide (TiO2) nanomaterials are widely considered to be state-of-the-art photocatalysts for environmental protection and energy conversion. However, the low photocatalytic efficiency caused by large bandgap and rapid recombination of photo-excited electrons and holes is a challenging issue that needs to be settled for their practical applications. Structure engineering has been demonstrated to be a highly promising approach to engineer the optical and electronic properties of the existing materials or even endow them with unexpected properties. Surface structure engineering has witnessed the breakthrough in increasing the photocatalytic efficiency of TiO2 nanomaterials by creating a defect-rich or amorphous surface layer with black color and extension of optical absorption to the whole visible spectrum, along with markedly enhanced photocatalytic activities. In this review, the recent progress in the development of black TiO2 nanomaterials is reviewed to gain a better understanding of the structure-property relationship with the consideration of preparation methods and to project new insights into the future development of black TiO2 nanomaterials in photocatalytic applications.

Structure-property relations of liquid crystalline polymers

1987 ◽  
Vol 45 ◽  
pp. 460-463
Author(s):  
Linda C. Sawyer
Keyword(s):  
Solid State ◽  
Liquid Crystalline ◽  
Structural Model ◽  
Crystalline Polymer ◽  
Liquid Crystalline Polymers ◽  
Mechanical Anisotropy ◽  
Structure Property ◽  
Preparation Methods ◽  
Crystalline Polymers ◽  
Extended Chain

Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.

Synthesis of Cu Loaded TiO2 Nanoparticles for the Improved Photocatalytic Degradation of Rhodamine B

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660002 ◽  
Author(s):  
V. Kavitha ◽  
P. S. Ramesh ◽  
D. Geetha
Keyword(s):  
Titanium Dioxide ◽  
Rhodamine B ◽  
Sol Gel ◽  
Average Particle Size ◽  
Visible Spectrum ◽  
Xrd Analysis ◽  
Bandgap Energy ◽  
Average Particle ◽  
Titanium Tetraisopropoxide ◽  
Photoexcited Electron

Copper doped Titanium dioxide TiO2 nanoparticles were synthesized by sol–gel method using titanium tetraisopropoxide and copper sulfate as precursors. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), Photoluminesce spectroscopy (PL) and atomic force microscopy (AFM). XRD analysis confirms the formation of anatase titanium dioxide and average particle size was 35[Formula: see text]nm. Cu– TiO2 exhibits a shift in the absorption edge toward visible spectrum. The rate of recombination and transfer behavior of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. From SEM spherical shaped nanoparticles was observed. Comparing with pure TiO2 nanoparticles, Cu doped TiO2 photocatalyst exhibited enhanced photocatalytic activity under natural sunlight irradiation in the decomposition of rhodamine B aqueous solution. The maximum 97% of degradation efficiency of Rhodamine B was observed at 0.6% Cu–TiO2 within 180[Formula: see text]min. The photocatalytic efficiency of Rhodamine B of Cu doped TiO2 nanoparticle was higher than the pure TiO2, which could be attributed to the small crystallinity intense light absorption in Sunlight and narrow bandgap energy of Copper.

Effect of the calcination temperature on the photocatalytic efficiency of acidic sol–gel synthesized TiO2nanoparticles in the degradation of alprazolam

2017 ◽  
Vol 16 (6) ◽  
pp. 935-945 ◽  
Author(s):  
Andreia Romeiro ◽  
Diana Freitas ◽  
M. Emília Azenha ◽  
Moisés Canle ◽  
Hugh D. Burrows
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Psychoactive Drug ◽  
Photocatalytic Efficiency ◽  
Titanium Dioxide Photocatalysis

The benzodiazepine psychoactive drug alprazolam is efficiently photodegraded and mineralized in aqueous solution using titanium dioxide photocatalysis.

scholarly journals Compressive Sensing Based Three-Dimensional Imaging Method with Electro-Optic Modulation for Nonscanning Laser Radar

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 748
Author(s):  
Yulong An ◽  
Yanmei Zhang ◽  
Haichao Guo ◽  
Jing Wang
Keyword(s):  
Compressive Sensing ◽  
3D Imaging ◽  
Low Cost ◽  
Functional Model ◽  
Three Dimensional ◽  
Visible Spectrum ◽  
Depth Map ◽  
Imaging Method ◽  
Practical Applications ◽  
Electro Optic

Low-cost Laser Detection and Ranging (LiDAR) is crucial to three-dimensional (3D) imaging in applications such as remote sensing, target detection, and machine vision. In conventional nonscanning time-of-flight (TOF) LiDAR, the intensity map is obtained by a detector array and the depth map is measured in the time domain which requires costly sensors and short laser pulses. To overcome such limitations, this paper presents a nonscanning 3D laser imaging method that combines compressive sensing (CS) techniques and electro-optic modulation. In this novel scheme, electro-optic modulation is applied to map the range information into the intensity of echo pulses symmetrically and the measurements of pattern projection with symmetrical structure are received by the low bandwidth detector. The 3D imaging can be extracted from two gain modulated images that are recovered by solving underdetermined inverse problems. An integrated regularization model is proposed for the recovery problems and the minimization functional model is solved by a proposed algorithm applying the alternating direction method of multiplier (ADMM) technique. The simulation results on various subrates for 3D imaging indicate that our proposed method is feasible and achieves performance improvement over conventional methods in systems with hardware limitations. This novel method will be highly valuable for practical applications with advantages of low cost and flexible structure at wavelengths beyond visible spectrum.

scholarly journals Application of Titanium Dioxide-Graphene Composite Material for Photocatalytic Degradation of Alkylphenols

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Chanbasha Basheer
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Photocatalytic Efficiency ◽  
Ionization Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Flame Ionization ◽  
Transmission Electron ◽  
Wastewater Samples

Titanium dioxide-graphene (TiO2-G) composite was used for the photodegradation of alkylphenols in wastewater samples. The TiO2-G composites were prepared via sonochemical and calcination methods. The synthesized composite was characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and fluorescence spectroscopy. The photocatalytic efficiency was evaluated by studying the degradation profiles of alkylphenols using gas chromatography-flame ionization detector (GC-FID). It was found that the synthesized TiO2-G composites exhibit enhanced photocatalytic efficiencies as compared to pristine TiO2. The presence of graphene not only provides a large surface area support for the TiO2photocatalyst, but also stabilizes charge separation by trapping electrons transferred from TiO2, thereby hindering charge transfer and enhancing its photocatalytic efficiency.

Research on Optical Property of Black-Colored Zirconia Ceramics by Photoluminescence, Raman and Visible Reflectivity Spectra

2017 ◽  
Vol 726 ◽  
pp. 174-178
Author(s):  
Yue Xu ◽  
Ren Li Fu ◽  
Yang Yang ◽  
Jun De Cai ◽  
Xu Wang ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Visible Spectrum ◽  
X Ray Diffraction ◽  
Zirconia Ceramics ◽  
X Ray ◽  
Reducing Atmosphere ◽  
Reflectivity Spectra ◽  
Crystal Density ◽  
Uv Visible ◽  
Black Color

White color zirconia ceramics were produced by sintering of coprecipitated 3Y-TZP powder in air. By annealing at reducing atmosphere, black-color zirconia ceramics with different shades were then realized. The obtained ZrO2 samples were characterized by X-ray diffraction (XRD), UV-visible spectrum (UV-vis), photoluminescence spectra (PL) and Raman spectroscopy, respectively. UV-visible spectrum reveals that the ZrO2 samples under different reducing atmosphere have different reflectivity in 400-800nm. X-ray diffraction data confirms that the different annealing processes can result in the change of the corresponding crystal density. It is indicated that defects contributes to cell volume alteration. The PL and Raman spectra further indicates that these defects belong to oxygen vacancies and the concentration of oxygen vacancies have a strong influence on the shades of black-color zirconia ceramics.

COMPOSITES OF THE TITANIA THIN FILMS IMPLANTED BY Ge AND Si

2011 ◽  
Vol 25 (12) ◽  
pp. 1629-1635 ◽  
Author(s):  
YANJUN ZHOU ◽  
FANG HE ◽  
YUAN HUANG ◽  
YIZAO WAN ◽  
YULIN WANG
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Photoelectron Spectroscopy ◽  
Quartz Substrate ◽  
Visible Region ◽  
Silicon Oxides ◽  
Practical Applications ◽  
Chemical States ◽  
Titanium Dioxide Thin Films ◽  
Implantation Method

By using reactive magnetron sputtering system, titanium dioxide thin films were fabricated onto quartz substrate, and then modified by Ge and Si atoms that were introduced with ion implantation method. XRD, AFM, XPS, and UV-vis were used to characterize these films, and X-ray photoelectron spectroscopy (XPS) was adopted to examine the atomic chemical states of implanted titanium dioxide thin films. The results show that there are Ge and silicon oxides precipitations in TiO 2 matrices. The implanted Ge + Si thin film exhibits an intense absorption band within visible region, which will further benefit its practical applications.

Visible spectrum of titanium dioxide

2010 ◽  
Vol 12 (45) ◽  
pp. 15018 ◽  
Author(s):  
Xiujuan Zhuang ◽  
Anh Le ◽  
Timothy C. Steimle ◽  
Ramya Nagarajan ◽  
Varun Gupta ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Visible Spectrum
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