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.

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.

Preparation and Application of Titanate Nanotubes on Methylene Blue Degradation from Aqueous Media

2011 ◽  
Vol 117-119 ◽  
pp. 786-789 ◽  
Author(s):  
Wen Churng Lin ◽  
Wein Duo Yang ◽  
Zen Ja Chung ◽  
Hui Ju Chueng
Keyword(s):  
Methylene Blue ◽  
Surface Area ◽  
Uv Irradiation ◽  
Aqueous Media ◽  
Hydrothermal Process ◽  
Reaction Times ◽  
Titanate Nanotubes ◽  
Methylene Blue Degradation ◽  
Bet Analysis

Titanate nanotubes were synthesized at various hydrothermal temperatures and reaction times by the hydrothermal process and used as photocatalyst. BET analysis was conducted in order to find out the surface area of these as-prepared samples and it was found that the surface area increases with rise in temperature till 130 oC. Synthesized as-prepared titanate nanotubes were applied on methylene blue degradation from aqueous media by UV irradiation. It was observed that dye removes ~99% from the aqueous media at a titanate nanotubes dose of 2 g/L.

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) 

Bi2WO6 Nanoparticles Prepared by Combustion Synthesis with Different Fuels and their Photocatalytic Activity

2014 ◽  
Vol 604 ◽  
pp. 93-101
Author(s):  
Maris Kodols ◽  
Sabine Didrihsone ◽  
Janis Grabis
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Citric Acid ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Crystallite Size ◽  
Combustion Synthesis ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solution Ph

The influence of glycine, glycerine, ethylene glycol and citric acid fuel and their ratio to NO3- on formation and dispersity of Bi2WO6 nanoparticles prepared by combustion synthesis has been studied. The pure crystalline Bi2WO6 with specific surface area 24,8 m2/g and crystallite size of 28 nm was obtained by using glycerine as fuel at its ratio to NO3- of 0,67. The photocatalytic activity of the prepared Bi2WO6 in degradation of methylene blue depended on its specific surface area of samples and solution pH.

scholarly journals Titanium dioxide modified with manganese: physicochemical and photocatalytic properties

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 214-218
Author(s):  
S. A. Safaryan ◽  
◽  
M. L. Belikov ◽  
V. A. Krysanova ◽  
◽  
...  
Keyword(s):  
Methylene Blue ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Phase Composition ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Organic Dyes ◽  
Photocatalytic Properties

The article presents the results of the studies of the physicochemical and photocatalytic properties of titanium dioxide modified with manganese, by the example of decomposition of organic dyes — ferroin and methylene blue. The correlations between the specific surface area and phase composition of the composites with their photocatalytic activity are revealed.

scholarly journals Preparation and photocatalytic activity of the layered titanates

2010 ◽  
Vol 4 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Marija Milanovic ◽  
Ivan Stijepovic ◽  
Ljubica Nikolic
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Bet Method ◽  
Ft Ir

Titanate structures were synthesized in highly alkaline solution using hydrothermal procedure. As-prepared powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). A specific surface area of the powders was measured by BET method. Results confirmed formation of layered trititanates, already after one hour of hydrothermal synthesis. To examine the photocatalytic activity of the as-prepared layered titanates, methylene blue (MB) was employed as a target compound in response to visible light at ambient temperature. It was observed that the specific surface area, size distribution and crystallinity are important factors to get high photocatalytic activity for the decomposition of MB. .

scholarly journals Enhanced Photocatalytic Activity for Degradation of Methyl Orange over Silica-Titania

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Yaping Guo ◽  
Shaogui Yang ◽  
Xuefei Zhou ◽  
Chunmian Lin ◽  
Yajun Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Specific Surface ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Anatase Phase ◽  
Solution Treatment ◽  
X Ray

Silica-modified titania (SMT) powders with different atomic ratios of silica to titanium (Rx) were successfully synthesized by a simple ultrasonic irradiation technique. The prepared samples were characterized by X-ray diffraction (XRD), FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible spectroscopy. The specific surface area was measured according to BET theory. Results indicate that the addition of silica to titania can suppress the crystalline size growth and the transformation of anatase phase to rutile phase of titania, enlarge specific surface area of the titania particles, and result in a blue shift of absorption edge compared to pure titania. The photocatalytic activity of the SMT samples was evaluated by decolorizing methyl orange aqueous solutions under UV-visible light irradiation. It was found in our study that this activity was affected by silica content, calcination temperature, H2SO4, and oxidants such as KIO4, (NH4)2S2O8and H2O2. The results reveal that the photocatalytic activity of 0.1-SMT catalyst is the best among all samples calcined at550°C for 1 h and it is 1.56 times higher than that of Degussa P-25 titania, which is a widely used commercial TiO2made by Germany Degussa company and has been most widely used in industry as photocatalyst, antiultraviolet product, and thermal stabilizer. The optimal calcination temperature for preparation was550°C. The photocatalytic activity of SMT samples is significantly enhanced by H2SO4solution treatment and oxidants.

Enhancement of Photocatalytic Activity of TiO2 Thin Film Using Diethanolamine and MCM-41

2012 ◽  
Vol 712 ◽  
pp. 117-131 ◽  
Author(s):  
Ananta Kumar Karki ◽  
Nurak Grisdanurak ◽  
Siriluk Chiarakorn
Keyword(s):  
Thin Film ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Surface Area ◽  
Anatase Phase ◽  
Sol Gel ◽  
Dip Coating ◽  
Bet Surface Area ◽  
Mcm 41

TiO2thin film enhanced by diethanolamine (DEA) and MCM-41 (D-TiO2/MCM-41) was successfully synthesized by sol-gel dip coating technique on glass slides. The roles of DEA and MCM-41 on physical and photocatalytic characteristics of the films were studied using various techniques such as x-ray defraction (XRD), fourier transform infrared spectroscopy (FTIR), ultra violet-visible (UV-Vis) spectrometry, Brunauer, Emmett and Teller (BET) surface area analysis and field emission scanning electron microscope (FESEM). The XRD results showed that the thin film contained almost 100% anatase phase and the crystal size of TiO2was in the range of 4-8 nm. The FTIR spectra indicated the formation of Ti-O-Si and Si-O-Si linkages due to interaction of TiO2and MCM-41. The surface area of TiO2was increased significantly when MCM-41 was added. The use DEA and MCM-41 caused slight increase in visible light absorption but UV absorption was decreased. The photocatalytic reactivity of the thin film was tested by photocatalytic degradation of methylene blue under visible light. The addition of DEA as a nitrogen source was beneficial not only for obtaining stable/smooth surface of the thin film but also for enhancing photocatalysis of methylene blue by preventing charge carrier recombination. While MCM-41 played important functions in improving porosity and hydrophilicity of the film. The photodegradation of methylene blue was obtained up to 35% of its original concentration when 1M DEA and 0.3M MCM-41 were incorporated in TiO2thin film. The overall enhancement of photocatalytic activity of the film was a result of nitrogen doping, increased surface area as well as increased hydrophilicity provided by MCM-41.

Photocatalytic Cement by TiO2 Addition

2012 ◽  
Vol 712 ◽  
pp. 65-72
Author(s):  
Pradeepan Periyat ◽  
A.S. Divya ◽  
K.G.K. Warrier
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Photo Catalytic Activity ◽  
Further Development ◽  
White Portland Cement

Photocatalytically active TiO2 and silica doped TiO2(Si-TiO2) synthesised using an aqueous sol-gel method and is characterised by particle size analysis, XRD, diffuse reflectance spectra and BET measurements. The photocatalytic analysis using methylene blue proved that the Si-TiO2possesses higher activity than pure TiO2. This Si-TiO2having higher photo-catalytic activity was incorporated into white portland cement and this modified cement exhibited photo-catalytic activity as evaluated by using methylene blue degradation experiments. This novel work is considered to be useful for further development of self-cleaning cements. Moreover silica doped to TiO2improved surface area and thermal stability of anatase TiO2significantly. At 800оC, 100 percentage anatase phase was obtained for Si-TiO2whereas pure TiO2showed 100 percentage rutile phase at the same temperature and surface aera of the Si-TiO2was 93 m2/g while pure TiO2showed only 2 m2/g.

scholarly journals Relationship between Synthesis Conditions and Photocatalytic Activity of Nanocrystalline TiO2

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Yosep Han ◽  
Hyung-Seok Kim ◽  
Hyunjung Kim
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Molar Ratio ◽  
Hydroxyl Groups ◽  
Synthesis Conditions

The degradation efficiency of methylene blue by TiO2nanoparticles, which were synthesized under different synthesis conditions (i.e., molar ratio of water and titanium tetraisopropoxide (TTIP), pH, and calcination temperature) in a sol-gel process, was systematically investigated. The results showed that increasing the molar ratio of water and TTIP led to the enhanced photocatalytic activity of TiO2nanoparticles, which were likely attributed to the increased specific surface area of TiO2nanoparticles synthesized with high molar ratio. The results were supported by the relative increase in the size of interaggregated pores of the aggregated TiO2nanoparticles. The best photocatalytic activity of TiO2nanoparticles was observed at acidic synthesis conditions; however, the results were not consistent with physical properties for the crystallinity and the crystallite size of TiO2nanoparticles but rather explained by the presence of abundant hydroxyl groups and water molecules existing on the surface of TiO2under acidic synthesis environments. Furthermore, methylene blue degradation experiments revealed that the photocatalytic activity of TiO2nanoparticles was maximized at the calcination temperature of 700°C. The trend was likely due to the combined effect of the anatase crystallinity which showed the highest value at 700°C and the crystallite size/specific surface area which did not excessively increase up to 700°C.

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