scholarly journals Enhanced Photocatalytic Activity of Powders (P25) via Calcination Treatment

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Guohong Wang ◽  
Lin Xu ◽  
Jun Zhang ◽  
Tingting Yin ◽  
Deyan Han
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Bet Surface Area ◽  
Photocatalytic Activities ◽  
Before And After ◽  
Different Temperatures ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Calcination Treatment

P25 TiO2powders were calcined at different temperatures in a muffle furnace in air. The P25 powders before and after calcination treatment were characterized with XRD FTIR, UV-visible diffuse reflectance spectra, SEM, TEM, HRTEM, and N2adsorption-desorption measurements. The photocatalytic activity was evaluated by the photocatalytic oxidation of methyl orange aqueous solution under UV light irradiation in air. The results showed that calcination treatment obviously influenced the microstructures and photocatalytic activity of the P25 TiO2powders. The synergistic effect of the phase structure, BET surface area, and crystallinity on the photocatalytic of TiO2powders (P25) after calcination was investigated. An optimal calcination temperature () was determined. The photocatalytic activity of TiO2powders calcined at was nearly 2 times higher than that of the uncalcined P25 TiO2. The highest photocatalytic activities of the calcined samples at for 4 h might be ascribed to the enhancement of anatase crystallization and the optimal mass ratio (ca. 1 : 2) of rutile to anatase.

Facile Preparation of Nanoporous SnO2 for Application in Photodegradation of Methylene Blue

2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
High Photocatalytic Activity ◽  
N2 Adsorption ◽  
Photochemical Method ◽  
Degussa P25 ◽  
Adsorption Desorption

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.

Preparation, Characterization and Photocatalytic Activity of F, Fe-Codoped Nano-TiO2

2013 ◽  
Vol 448-453 ◽  
pp. 169-173
Author(s):  
Chun Yan Yan ◽  
Wen Tao Yi
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Hydrothermal Process ◽  
Neutral Red ◽  
Reaction Model ◽  
X Ray Diffraction ◽  
Pseudo First Order Reaction ◽  
Adsorption Desorption ◽  
Desorption Method

Pure and F, Fe-codoped TiO2 were prepared by sol-hydrothermal process, in which titanium (IV) n-butoxide, Fe (NO3)2·6H2O and NH4F were used as precursors. And the samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and N2 adsorption-desorption method. The results showed that the F, Fe-codoped samples were principally single-phase anatase structures, and the particles possessed higher BET area than that of pure TiO2. The photocatalytic activity and reusability of the catalysts under UV light (365nm) was investigated with neutral red as the model compound. The results showed that F (2.0%), Fe (4.0%) codoped TiO2 had the highest photocatalytic activity among all as-prepared samples. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

Characterization and Photocatalytic Evaluation (UV-Visible) of Fe-doped TiO2 Systems Calcined at Different Temperatures

2015 ◽  
Vol 18 (1) ◽  
Author(s):  
Ximena María Vargas ◽  
Juan Miguel Marin ◽  
Gloria Restrepo
Keyword(s):  
Photocatalytic Activity ◽  
Solar Spectrum ◽  
Doped Tio2 ◽  
Different Temperatures ◽  
Uv Visible ◽  
Intense Research

AbstractThere is growing interest in obtaining compounds with photocatalytic activity in the solar spectrum, and this has led to intense research on the topic. In our laboratory, Fe-doped TiO

V and F Codoped TiO2-SiO2 Composite Films for Enhanced Photocatalytic Activity

2014 ◽  
Vol 955-959 ◽  
pp. 2384-2387
Author(s):  
Ling Xiao Guan ◽  
Yao Yao
Keyword(s):  
Photocatalytic Activity ◽  
Composite Film ◽  
Surface Area ◽  
Composite Films ◽  
Bet Surface Area ◽  
Methyl Green ◽  
Simple Process ◽  
Vis Spectroscopy ◽  
Excellent Photocatalytic Activity ◽  
Photocatalytic Activities

A simple process was developed for preparation of highly photoactive V and F codoped TiO2-SiO2 composite film. The as-prepared specimens were characterized using Brunauer–Emmett–Teller (BET) surface area, photoluminescence (PL) spectra, and UV–Vis spectroscopy. The BET results revealed that the surface area of the modified TiO2 sample was 413 m2 g-1, while pure TiO2 103 m2 g-1. The PL results showed that the recombination rate of the photo-generated electrons and holes was effectively prohibited via the multi-modification. The photocatalytic activities of the films were evaluated by degradation of methyl green (MG) dye. Compared with pure TiO2 film, the multi-modified TiO2 film exhibited excellent photocatalytic activity and clearly responsive to the visible light. Keywords: V and F codoping; TiO2-SiO2 composite film; Photocatalytic activity

Synthesis and photocatalytic activities of Nd-doped TiO2 mesoporous microspheres

2016 ◽  
Vol 09 (01) ◽  
pp. 1650013 ◽  
Author(s):  
Xijian Liu ◽  
Yangang Sun ◽  
Yeying Wang ◽  
Lijuan Zhang ◽  
Jie Lu
Keyword(s):  
Electron Microscopy ◽  
Light Irradiation ◽  
Xenon Lamp ◽  
X Ray Diffraction ◽  
Absorbance Spectroscopy ◽  
Transmission Electron ◽  
Mesoporous Microspheres ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Adsorption Desorption

Nd-doped TiO2 mesoporous microspheres with possessing regular micro/nanostructure were synthesized by a simple and facile method. The structure and optical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms and UV-Visible absorbance spectroscopy. It was revealed that Nd-doped TiO2 mesoporous microspheres are composed of primary nanoparticles with a particle size of [Formula: see text]25[Formula: see text]nm. The photocatalytic activities of all the samples were evaluated by degradation methyl orange (MO) in aqueous solution as a model reaction under xenon lamp light irradiation. The results showed that the doped samples demonstrated a higher photocatalytic activity than TiO2 mesoporous microspheres, and the MO of 10[Formula: see text]mg/mL almost could be completely degraded by the Nd-doped TiO2 mesoporous sample (the dosage of Nd salt to TiO2 is 6%) under xenon lamp light irradiation within 1[Formula: see text]h.

Controllable Synthesis and Photocatalytic Activity of Ba0.6Mg0.4TiO3 Particles with Different Morphologies

2014 ◽  
Vol 955-959 ◽  
pp. 2267-2275 ◽  
Author(s):  
Rong Liu ◽  
Shi Duo Zhao ◽  
Xue Lin
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Hydrothermal Process ◽  
Light Irradiation ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Xrd Patterns

Ba0.6Mg0.4TiO3 (BMT) particles with different morphologies were synthesized through hydrothermal method and their optical and photocatalytic properties were investigated. Their crystal structure and microstructures were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns demonstrate that the as-prepared samples are tetragonal structure. FESEM shows that BMT crystals can be fabricated in different morphologies by simply manipulating the reaction parameters of hydrothermal process. The UV-visible diffuse reflectance spectra (UV-vis DRS) reveal that the band gaps of BMT photocatalysts are about 2.37 - 2.51 eV. The as-prepared BMT photocatalysts exhibite higher photocatalytic activities in the degradation of methyl orange (MO) under visible light irradiation (λ > 420 nm) compared with traditional N-doped TiO2 (N-TiO2) and pure BaTiO3 (BTO). The high photocatalytic performance of BMT photocatalysts could be attributed to the recombination restraint of the e-/h+ pairs resulting from doping of Mg2+ ions. The influence of morphologies upon the photocatalytic properties of BMT was studied. Furthermore, BMT nanowires reveal the highest photocatalytic activity. Up to 94.0% MO is decolorized after visible light irradiation for 360 min.

scholarly journals Preparation and Characterization of(I2)nSensitized NanoporousTiO2with Enhanced Photocatalytic Activity under Visible-Light Irradiation

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Juzheng Zhang ◽  
Xin Liu ◽  
Shanmin Gao ◽  
Quanwen Liu ◽  
Baibiao Huang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Chemical Properties ◽  
Reaction Model ◽  
Raw Material ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Adsorption Desorption

A yellow/brown powder of(I2)nsensitized nanoporous TiO2was obtained via an hydrolysis with TiCl4and iodine hydrosol as raw material. I2nanoparticles in the hydrosol were used as seeds to initiate the nucleation of a precursory TiO2shell. The hybridized jumbles were further calcinated at different temperatures. The structure, crystallinity, morphology, and other physical-chemical properties of the samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2adsorption-desorption isotherms measurements, and UV-vis diffuse reflectance spectroscopy (DRS). The formation mechanism of these(I2)nsensitized nanoporous TiO2is discussed. Methylene blue solutions were used as model wastewater to evaluate the visible light photocatalytic activity of the samples. The results indicate that iodine can exist even in high-temperature calcination for iodine being encapsulated in the nanocavities inside TiO2. The degradation of methylene blue (MB) accorded with the first-order reaction model.

scholarly journals Synthesis and Characterization of Electrospun Nanocomposite Nanofibers with Ag Nanoparticles for Photocatalysis Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Srujan Mishra ◽  
S. Phillip Ahrenkiel
Keyword(s):  
Photocatalytic Activity ◽  
Ag Nanoparticles ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Dark Field ◽  
Mixed Phase ◽  
Methyl Red ◽  
Fiber Morphology ◽  
Electrospinning Technique ◽  
Red Dye

Polycrystalline mixed-phase TiO2nanofibers embedded with 2.0% w/v Ag nanoparticles was prepared by the electrospinning technique. Calcination of dry Ag nanoparticles-titanium (IV) isopropoxide/PVP electrospun nanofiber mats in air at for 24 h yielded polycrystalline TiO2/Ag nanofibers. The morphology and distribution of silver nanoparticles were observed by transmission electron microscopy (TEM), scanning TEM (STEM), and high-angle annular dark-field (HAADF) imaging. Mixed-phase anatase and rutile TiO2nanofibers were produced with Ag nanoparticles. High-resolution TEM lattice-fringe measurements showed good agreement with Ag (111), anatase (101), and rutile (110) phases. The photocatalytic activity of TiO2/Ag nanofibers was compared to the photocatalytic activity of pure TiO2nanofibers by studying the photodegradation of methyl red dye under UV light irradiation, in a photoreactor. UV-visible absorbance spectra showed that the rate of decay of the dye in case of photodegradation by TiO2/Ag nanofibers was 10.3 times higher than that by pure TiO2nanofibers. The retaining of the fiber morphology along with the increased surface area due to the addition of Ag nanoparticles can be believed to enhance the photocatalytic oxidation of methyl red dye.

scholarly journals Ultrasound-Assisted Rapid ZIF-8 Synthesis, Porous ZnO Preparation by Heating ZIF-8, and Their Photocatalytic Activity

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Pham Dinh Du ◽  
Nguyen Trung Hieu ◽  
Tran Vinh Thien
Keyword(s):  
Photocatalytic Activity ◽  
Room Temperature ◽  
Diffuse Reflectance ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Adsorption Desorption

Zeolitic imidazolate framework-8 (ZIF-8) is synthesized quickly at room temperature in methanol with the support of ultrasound. Porous ZnO is also prepared via the thermal treatment of ZIF-8. The photocatalytic activities of the obtained materials are demonstrated via methylene blue (MB) decomposition under UV radiation. The obtained materials are characterized by means of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption/desorption isotherms, UV-Vis diffuse reflectance spectra (DR-UV-Vis), and photoluminescence spectra. The results indicate that ZIF-8 and the materials obtained from ZIF-8 by heating in the air have photocatalytic activity under UV irradiation. The ZnO sample obtained by ZIF-8 calcination at 660°C for 5 h has the highest photocatalytic activity. However, the MB degradation photocatalytic efficiency of the ZnO samples is even lower than that of the ZIF-8 samples, indicating that ZIF-8 is an effective photocatalyst in the treatment of environmental pollution.

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