scholarly journals Fabrication, N-doping Mechanism and Evaluation of N-doped TiO2 Thin Films Based on Laser Ablation Method

2009 ◽  
Vol 2 (1) ◽  
pp. 17-23 ◽  
Author(s):  
S. Somekawa ◽  
Y. Kusumoto ◽  
H. Yang ◽  
M. Abdulla-Al-Mamun ◽  
B. Ahmmad
Keyword(s):  
Crystal Structure ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Laser Ablation ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Laser Ablation Method ◽  
Dye Decomposition ◽  
N Doping ◽  
Keywords Laser

The relation among the change of the crystal structure, the amount of doped N and the photocatalytic activity for the decomposition of methylene blue was studied. The N-doping was promoted by the change of the crystal structure from the rutile phase to the anatase phase. The photocatalytic activity for the decomposition of methylene blue was enhanced by an increase in the amount of anatase crystals and doped N. Keywords: Laser ablation; N-doping process; Crystal change; N-doped TiO2 thin film; Dye decomposition. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2992        J. Sci. Res. 2 (1), 17-23 (2010) 

Application of Fibrous TiO2 as a Photocatalyst in Aqueous Media

2006 ◽  
Vol 45 ◽  
pp. 951-956
Author(s):  
Hidekazu Tanaka ◽  
Ikuyo Higashio ◽  
Keiichi Watanabe ◽  
Yoko Suyama
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Uv Irradiation ◽  
Anatase Phase ◽  
Aqueous Media ◽  
Rutile Phase ◽  
High Photocatalytic Activity

Fibrous TiO2 with ca. 0.16 mm in width and 5 - 6 cm in length was prepared by drying a suspension of monodispersed anatase particles at 363 K in air. The TiO2 fibers thus obtained were thermally treated at the temperatures ranging from 363 to 1273 K for 1 h in air. Elevating the treating temperature increases the crystallinity of anatase phase and reduces the specific surface area from 98 to 5 m2/g due to the sintering of particles. The rutile phase appears at 1273 K by transformation of anatase phase. A photocatalytic activity of the fibers was examined by decomposition of methylene blue (MB) in water under UV irradiation centered at 365 nm. The fibers decomposed the MB in aqueous media under UV irradiation, indicating that the fibers possess a high photocatalytic activity. The catalytic activity is considered to be enhanced on increasing the crystallinity of anatase phase, nevertheless, that decreased with generation of rutile phase.

Influence of anatase and rutile phase in TiO2 upon the photocatalytic degradation of methylene blue under solar irradiation in presence of activated carbon

2014 ◽  
Vol 69 (11) ◽  
pp. 2184-2190 ◽  
Author(s):  
J. Matos ◽  
R. Montaña ◽  
E. Rivero ◽  
A. Escudero ◽  
D. Uzcategui
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Photocatalytic Degradation ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Solar Irradiation ◽  
Exponential Trend ◽  
Visible Irradiation ◽  
Binary Material

The influence of activated carbon (AC) on the photocatalytic activity of different crystalline TiO2 phases was verified in the photocatalytic degradation of methylene blue under UV and solar irradiation. The results showed a volcano trend with a maximum photoactivity for the crystalline phase ratio of anatase:rutile equal to 80:20 both under UV or solar irradiation. By contrast, in presence of AC the photocatalytic activity of the binary materials of TiO2/AC followed an exponential trend, increasing as a function of the increase in anatase proportion in the TiO2 framework. The increase in the photoactivity of the binary material TiO2/AC relative to neat TiO2 was up to 22 and about 17 times higher under UV and visible irradiation, respectively. The present results suggest that AC interacts more efficiently with anatase phase than with rutile phase.

scholarly journals Unexpected Link between the Template Purification Solvent and the Structure of Titanium Dioxide Hollow Spheres

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Tamás Gyulavári ◽  
Kata Kovács ◽  
Klára Magyari ◽  
Kornélia Baán ◽  
Anna Szabó ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Phase Composition ◽  
Anatase Phase ◽  
Hollow Spheres ◽  
Rutile Phase ◽  
Carbon Sphere ◽  
Carbon Spheres ◽  
Carbonate Species ◽  
Determining Factor

Carbon spheres were applied as templates to synthesize titanium dioxide hollow spheres. The templates were purified with either ethanol or acetone, and the effects of this treatment on the properties of the resulting titania were investigated. The photocatalytic activity of the catalysts was measured via the decomposition of phenol model pollutant under visible light irradiation. It was found that the solvent used for the purification of the carbon spheres had a surprisingly large impact on the crystal phase composition, morphology, and photocatalytic activity. Using ethanol resulted in a predominantly rutile phase titanium dioxide with regular morphology and higher photocatalytic activity (r0,phenol = 3.9 × 10−9 M∙s−1) than that containing mainly anatase phase prepared using acetone (r0,phenol = 1.2 × 10−9 M∙s−1), surpassing the photocatalytic activity of all investigated references. Based on infrared spectroscopy measurements, it was found that the carbon sphere templates had different surface properties that could result in the appearance of carbonate species in the titania lattice. The presence or absence of these species was found to be the determining factor in the development of the titania’s properties.

scholarly journals Influence of Cu(NO3)2 content used in thermal shock method on the photocatalytic activity of Cu-Modified ZnO nanoparticles

2021 ◽  
Vol 5 (3) ◽  
pp. first
Author(s):  
Thế Luân Nguyễn ◽  
Tiến Khoa Lê ◽  
Châu Ngọc Hoàng ◽  
Hữu Khánh Hưng Nguyễn ◽  
Thị Kiều Xuân Huỳnh
Keyword(s):  
Crystal Structure ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Thermal Shock ◽  
Photoelectron Spectroscopy ◽  
Copper Content ◽  
Uv Light ◽  
Copper Nitrate ◽  
X Ray ◽  
Doped Zno

The Cu doped ZnO photocatalysts were prepared on ZnO substrate modified with copper nitrate by thermal shock method with different ratio % molar Cu : Zn = 0.3, 0.5, 1.0, 2.0 and 5.0 in order to study the impacts of copper content on the photocatalytic activity of ZnO under both UV and Vis light irradiation. The crystal structure, morphology bulk and surface were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Their photocatalytic activities were studied via time-dependent degradation of methylene blue in aqueous solution. The results exhibit that crystal structure and morphology of Cu doped ZnO photocatalysts is not modified significally than ZnO original but surface charateristicschanged greatly. The photocatalyst was doped with copper content under 2% showed formation of Cu species. These samples perform photocatalytic activity higher than ZnO. The CuNZO-0.05-500 had the highest rate constants for methylene blue degradation (kUV = 6,901 h-1, kVIS = 0,224 h-1), which are about 2.2 times and 1.3 times higher than unmodified ZnO under UV light and Vis light, respectively. However, the CuNZO-5.0-500 which had the formation of CuO phase and unchangeable ZnO's surface has photocatalytic activity similar to pure ZnO.

Effect of Anatase/Rutile Phase Ratio on the Photodegradation of Methylene Blue under UV Irradiation

2020 ◽  
Vol 998 ◽  
pp. 78-83
Author(s):  
Yi Yi Zaw ◽  
Du Ang Dao Channei ◽  
Thotsaphon Threrujirapapong ◽  
Wilawan Khanitchaidecha ◽  
Auppatham Nakaruk
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Band Gap ◽  
Surface Area ◽  
Calcination Temperature ◽  
Organic Compounds ◽  
Specific Surface Area ◽  
Uv Irradiation ◽  
Rutile Phase

Titanium dioxide (TiO2) is known as one of the widely used catalysts in photocatalysis process. Recently, the photocatalysis of TiO2 has been implied in water purification and treatment, particularly dyes and organic compounds degradations. Naturally, the TiO2 can be found in three phases including anatase, rutile and brookite; each phase has its own specific properties such as grain size, stability and band gap energy. In this work, the effect of calcination temperature on the structure, morphology and photocatalytic activity were investigated. The data suggested that the anatase/rutile ratio of TiO2 can be controlled through the calcination process. The phase transformation data strongly indicated the liner function between percentage of rutile phase and calcination temperature. The BET analysis provided the consistent data with XRD patterns by showing that the specific surface area was decreased by increasing calcination temperature. The photodegradation of methylene blue under UV irradiation proved that the mixed phase of anatase/rutile ratio at 78.5/21.5 provided the highest photocatalytic activity. The phase composition ratio can influence the nanoparticles properties including band gap, specific surface area and energy band structure. Therefore, the control of anatase/rutile ratio was an alternative to enhance the photocatalytic activity of TiO2 nanoparticles for dyes and organic compounds degradations.

scholarly journals Blue to Yellow Photoluminescence Emission and Photocatalytic Activity of Nitrogen Doping in TiO2Powders

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Gabriela Byzynski ◽  
Caue Ribeiro ◽  
Elson Longo
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Anatase Phase ◽  
Oh Radical ◽  
Additional Energy ◽  
Photoluminescence Emission ◽  
Radical Production ◽  
N Doping ◽  
Band Gap Structure

The defects caused by doping are important for understanding the increased photocatalytic activities of TiO2:N in organic reactions and in the evaluation of OH radical production after doping. TiO2:N was therefore synthesized using a modified polymeric method and N doping was performed by calcination with urea. The resulting powders were characterized using field emission scanning electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy, Raman spectroscopy, Fourier transformation infrared spectroscopy, and photoluminescence emission spectroscopy (PL). N doping did not alter the morphology of the nanoparticles, and the anatase phase predominated, with the retention of the rutile phase. The band gap values, superficial areas, and crystallite sizes of the powders decreased after doping. The PL results showed an additional energy level in the TiO2:N band gap structure as a result of TiO2lattice defects caused by doping. At low N contents, the powders showed continuous emissions from the blue region to the yellow region and a high N content shifted the PL emissions to the red region. These results suggest that the use of these powders could increase the efficiencies of solar cells and water-splitting processes. The photocatalytic activity of the powders under UVC illumination was confirmed for different organic dye molecules. The OH radical production did not change extensively after doping, as shown by experiments with terephthalic acid, and higher photocatalytic efficiencies in Rhodamine-B degradation under UVC illumination were achieved using the doped samples.

PHOTOCATALYTIC ACTIVITY OF NITROGEN AND FLUORINE CO-DOPED TITANIUM DIOXIDE PREPARED USING OF VARIOUS PH SOLUTIONS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3242-3247 ◽  
Author(s):  
MASAHIRO KATOH ◽  
AKIHIRO IMAYAMA ◽  
NARISUKE MORI ◽  
TOSHIHIDE HORIKAWA ◽  
TAHEI TOMIDA
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Uv Light ◽  
Anatase Phase ◽  
Wave Length ◽  
Green Light ◽  
Light Irradiation ◽  
Mixed Solution ◽  
Co Doped

Introducing different atoms into TiO 2 crystal lattice is a famous method to improve photocatalytic activity of TiO 2 under visible-light irradiation. In this paper, Nitrogen ( N ) and fluorine ( F ) co -doped TiO 2 powders were prepared by mixing TiCl 3 solutions with ammonium fluoride ( NH 4 F ). In preparation, we used NH 3- H 2 O solution for adjustment of pH values (pH 2, 7, and 9) of mixed solution. X-ray diffraction (XRD) indicated N , F - TiO 2 powders prepared at pH7 and pH9 contained only anatase phase, but the powders prepared at pH2 contained both anatase and rutile phase. The result of XRD also indicated N , F - TiO 2 powders prepared at pH7 had the smallest crystallite size. We measured photocatalytic activity of prepared N , F - TiO 2 powders by the decomposition of methylene blue. N , F - TiO 2 powder prepared at pH7 and pH9 showed same high photocatalytic activity under ultraviolet light irradiation (peak wave length = 352 nm). Furthermore, under green light LED irradiation (wave length = 525 nm), a sample prepared at pH7 decomposed methylene blue more quickly than any other samples. As the result, N , F - TiO 2 prepared at pH7 had the best catalytic activity under both UV-light and visible light in the all of N , F - TiO 2 prepared and reference TiO 2 photocatalyst (ST-01 produced by Ishihara Co. Ltd).

The nanocomposite of polyaniline and nitrogen-doped layered HTiNbO5with excellent visible-light photocatalytic performance

2014 ◽  
Vol 16 (26) ◽  
pp. 13409-13417 ◽  
Author(s):  
Chao Liu ◽  
Liang Wu ◽  
Jing Chen ◽  
Ji-yuan Liang ◽  
Chang-shun Li ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Charge Separation ◽  
Photocatalytic Performance ◽  
High Efficiency ◽  
Nitrogen Doped ◽  
Visible Light Photocatalytic Activity ◽  
N Doping ◽  
Visible Light Photocatalytic

N-doping and intercalation resulted in a PANI–N-HTiNbO5lamellar nanocomposite, which showed a dramatic enhanced visible-light photocatalytic activity and stability for the degradation of methylene blue (MB), due to the high efficiency of charge separation.

scholarly journals Fabrication, Characterization and Photocatalytic Activity of Copper Oxide Nanowires Formed by Anodization of Copper Foams

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5030
Author(s):  
Alaa M. Abd-Elnaiem ◽  
M. A. Abdel-Rahim ◽  
A. Y. Abdel-Latief ◽  
Ahmed Abdel-Rahim Mohamed ◽  
Kristina Mojsilović ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Organic Compound ◽  
Organic Dye ◽  
Photocatalytic Efficiency ◽  
Voltage Range ◽  
Oxide Nanowires ◽  
Dye Decomposition ◽  
Photocatalytic Decolorization ◽  
Developed Surface

In recent paper anodization of copper foams in 0.1 M K2CO3 is reported. Anodization was performed in the voltage range of 5–25 V and in all the cases oxides with a developed surface area were obtained. However, anodizing only at 20 and 25 V resulted in the formation of nanostruc-tures. In all the cases, the products of anodizing consisted of crystalline phases like cuprite (Cu2O), tenorite (CuO), parameconite (Cu4O3) as well as spertiniite (Cu(OH)2). Copper foams after ano-dizing were applied as catalysts in the photocatalytic decolorization of a model organic compound such as methylene blue. The highest photocatalytic activity was observed for samples anodized at 25 V and closely followed by samples anodized at 5 V. The anodized copper foams proved to be a useful material in enhancing the photocatalytic efficiency of organic dye decomposition.

scholarly journals Preparation of Multicycle GO/TiO2 Composite Photocatalyst and Study on Degradation of Methylene Blue Synthetic Wastewater

2019 ◽  
Vol 9 (16) ◽  
pp. 3282 ◽  
Author(s):  
Zhongtian Fu ◽  
Song Zhang ◽  
Zhongxue Fu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Raw Materials ◽  
Anatase Phase ◽  
Pure Tio2 ◽  
Synthetic Wastewater ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Composite Photocatalyst ◽  
Initial Ph

A series of composite photocatalysts were prepared by using graphene oxide (GO) prepared by modified Hummers method and TiO2 hydrogel prepared by using butyl titanate as raw materials. The composite photocatalyst was characterized through scanning electron microscope（SEM）, x ray diffraction （XRD）, and Raman spectroscopy, and the degradation effect of pure TiO2 and composite photocatalyst on methylene blue (MB) dye wastewater under different experimental conditions was studied. The results showed that TiO2 in composite photocatalyst was mainly anatase phase and its photocatalytic activity was better than pure TiO2. When the addition of GO reached 15 wt%, the photocatalytic activity was the highest. When 200 mg composite photocatalyst was added to 200 mL synthetic wastewater with a concentration of 10 mg/L and an initial pH of about 8, the degradation rate could reach 95.8% after 2.5 h. It is presumed that the photogenerated charges of GO/TiO2 composite photocatalyst may directly destroy the luminescent groups in the MB molecule and thus decolorize the wastewater, and no other new luminescent groups are generated during the treatment.

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