scholarly journals Enhancing the photoactivity of TiO2/SiO2 monolithic catalyst and its reusability for wastewater treatment

2019 ◽  
Vol 268 ◽  
pp. 07005
Author(s):  
Ngoc Diem Trinh Huynh ◽  
Kieu Duyen Vo ◽  
Thao Vy Nguyen ◽  
Minh Vien Le
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Dip Coating ◽  
Molar Ratio ◽  
Coating Process ◽  
Visible Light Region ◽  
Molar Ratios ◽  
Calcination Temperatures ◽  
Light Region

A series of TiO2/SiO2 photocatalysts were successfully synthesized by the sol-gel method. The TiO2/SiO2 monolith was also synthesized by dip-coating process. The crystalline structure of TiO2/SiO2 powders was identified as pure anatase. The photocatalytic activity of the TiO2/SiO2 powders was evaluated by photodegradation of 20 ppm methylene blue (MB) using a 26W lamp which has the wavelength in the visible light region under different Ti: Si molar ratios and calcination temperatures. The TiO2/SiO2 powders which have Ti: Si molar ratio of 85:15 (TS15) and calcined at 550tC showed the highest photodegradation yield of 84 % after 3h irradiation. Furthermore, the 550˚C calcined TS15 monolith performed the MB degradation yield of 88.9 % after 3h irradiation and its photoactivity still remained after 4 recycle times. The results of this study demonstrated that the TS15 monolith photocatalyst has a reasonable efficiency in the degradation of methylene blue, it could be a promising photocatalyst for removal and degradation of organic pollutants.

FABRICATION AND PHOTOCATALYTIC PROPERTIES OF TiO2 NANOFILMS CO-DOPED WITH Fe3+ AND Bi3+ IONS

2016 ◽  
Vol 23 (02) ◽  
pp. 1550099
Author(s):  
QIONGZHI GAO ◽  
XIN LIU ◽  
WEI LIU ◽  
FANG LIU ◽  
YUEPING FANG ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Dip Coating ◽  
Photocatalytic Properties ◽  
Molar Ratio ◽  
Coating Process ◽  
X Ray ◽  
Co Doped ◽  
Scanning Electron

In this work, the titanium dioxide ([Formula: see text]) nanofilms co-doped with [Formula: see text] and [Formula: see text] ions were successfully fabricated by the sol–gel method with dip-coating process. Methylene blue was used as the target degradation chemical to study the photocatalytic properties affected by different doping contents of [Formula: see text] and [Formula: see text] ions. The samples were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The results indicated that both pure [Formula: see text] nanofilms and single-doped samples possessed the photocatalytic activity in degradation of methylene blue. However, when the nanofilms co-doped with [Formula: see text] and [Formula: see text] ions were fabricated at the molar ratio of 3:1 ([Formula: see text]:[Formula: see text]), they exhibited the best photocatalytic activity after the heat treatment at [Formula: see text]C for 2[Formula: see text]h. The wettability property test indicated that the [Formula: see text] nanofilms co-doped with [Formula: see text] and [Formula: see text] ions in the molar ratio 3:1 owned an excellent hydrophilic property.

scholarly journals Photocatalytic Improvement under Visible Light inTiO2Nanoparticles by Carbon Nanotube Incorporation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mathana Wongaree ◽  
Siriluk Chiarakorn ◽  
Surawut Chuangchote
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Sol Gel ◽  
Multiwall Carbon Nanotubes ◽  
High Specific Surface Area ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Calcination Temperatures ◽  
Photocatalytic Activities ◽  
Multiwall Carbon

Photocatalytic activity ofTiO2nanoparticles was successfully enhanced by addition of multiwall carbon nanotubes (MWCNT) to make CNT/TiO2nanocomposites by sol-gel method at ambient temperature. CNT treated by HNO3 : H2SO4treatment (1 : 3 v/v) was mixed withTiO2nanoparticles at various molar ratios and calcination temperatures. The optimal molar ratio of CNT : TiO2was found at 0.05 : 1 by weight. The optimal calcination condition was 400°C for 3 h. From the results, the photocatalytic activities of CNT/TiO2nanocomposites were determined by the decolorization of 1 × 10−5 M methylene blue (MB) under visible light. CNT/TiO2nanocomposites could enhance the photocatalytic activity and showed faster for the degradation of MB with only 90 min. The degradation efficiency of the MB solution with CNT/TiO2nanocomposite achieved 70% which was higher than that with pristineTiO2(22%). This could be explained that CNT preventsTiO2from its agglomeration which could further enhance electron transfer in the composites. In addition, CNT/TiO2nanocomposites had high specific surface area (202 m2/g) which is very promising for utilization as a photocatalyst for environmental applications.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films

2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Silver Surface ◽  
Molar Ratios ◽  
Sol Gel Synthesis

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

Characterization and Photocatalytic Activity of Composite La-TiO2/ITO Thin-Film Electrodes

2009 ◽  
Vol 79-82 ◽  
pp. 899-902
Author(s):  
Ming Yi Chang ◽  
Wei Fu Wang ◽  
Yung Hsu Hsieh ◽  
Chen Yu Chang
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Molar Ratio ◽  
Xrd Pattern ◽  
Molar Ratios ◽  
Sem Image ◽  
Uniform Particles ◽  
Spherical Structure ◽  
Coating Method ◽  
Dip Coating Method

The different molar ratios of La/Ti (0.025, 0.050, 0.075 and 0.100) photocatalytic electrodes use in this study were synthesized by sol-gel method and dip-coating method. The XRD pattern of TiO2/ITO presents only anatase phases, [1] but for La-TiO2/ITO presents both anatase and rutile phases. The SEM image of the La-TiO2/ITO showed particles of regular shapes with smaller size (＜10nm) compared to the TiO2/ITO, which presented uniform particles of spherical structure and larger size （20nm）.The La-TiO2/ITO photocatalytic electrode with molar ratio 0.050 shows the best ability both on the absorbtion and photocatalytsis. Applied potential 2.0V would effectively increase the photoelectrocatlaytic activity under visible light irradiation.

Photocatalytic Properties of Nitrogen-Sulfur Co-Doped TiO2 Films Coated on Glass Fiber

2013 ◽  
Vol 781-784 ◽  
pp. 2237-2240 ◽  
Author(s):  
Benjamas Noophum ◽  
Lek Sikong ◽  
Kalayanee Kooptanond
Keyword(s):  
Photocatalytic Activity ◽  
Glass Fibers ◽  
Sol Gel ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Fluorescent Light ◽  
Co Doping ◽  
Light Region ◽  
Microstructure Morphology ◽  
Co Doped

The photocatalytic N-S co-doped TiO2films coated on glass fibers were successfully prepared by sol-gel, dip-coating and calcination methods. The effect of doping concentration on crystalline size, microstructure, morphology, optical property and photocatalytic activity was investigated. The films were characterized by XRD, SEM, EDS, UV-vis DRS and FT-IR. The photocatalytic activity was evaluated by the degradation of methylene blue (MB). N-S co-doping has an effect on light adsorption wavelength shifted to visible light region which can lower the band gap energy of N-S co-doped due to the replacement of O atom in TiO2by N and S atoms to form Ti-O-N and Ti-O-S structures. Thiourea, a source of nitrogen and sulfur could increase viscosity of sol used for coating on glass fibers, resulting in larger particles size and more surface roughness of the doped films.TiO2films with 5 mol% N-S co-doped showed an excellent photocatalytic performance under fluorescent light irradiation.

Preparation and Photocatalytic Activity of Titania Pillared Montmorillonite Doped with Boron

2011 ◽  
Vol 233-235 ◽  
pp. 519-522
Author(s):  
Qiu Yan Zhang ◽  
Xiang Feng Guo ◽  
Li Hua Jia ◽  
Xue Ju Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Diffuse Reflection ◽  
Sol Gel ◽  
Boron Doping ◽  
Reflection Spectra ◽  
Visible Light Region ◽  
Pillared Montmorillonite ◽  
Light Region ◽  
Gel Technique

Boron doping titanium pillared montmorillonite (B-Ti-mont) were prepared by the sol-gel technique using sodic montmorillonite (Na-mont) as a substrate. Several technics such as XRD, SEM, UV-vis diffuse reflection spectra were used to characterize the samples. The results showed that all of the samples were of anatase, the absorption in the visible light region was strengthened after doped with boron. The basic skeleton of montmorillonite did not change after doping. The photocatalyst with the boron mole content of 5% displayed the best photocatalytic performance.

Characterization and activity of visible-light driven TiO2 photocatalyst doped with tungsten

2010 ◽  
Vol 62 (9) ◽  
pp. 2128-2133 ◽  
Author(s):  
T. Putta ◽  
M. C. Lu ◽  
J. Anotai
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Anatase Phase ◽  
Sol Gel ◽  
Light Illumination ◽  
Visible Light Region ◽  
Light Region ◽  
Acid Type ◽  
Visible Light Driven ◽  
Amorphous Tio2

This research aimed to expand the activity of TiO2 down to the visible light region by modifying the sol-gel conditions and doping with tungsten. The optimum conditions for calcination temperature, acid type, and heating rate were 200°C, HNO3, and 1°C/min, respectively. The undoped TiO2 synthesized under these conditions could significantly absorb the visible light whereas the commercial Degussa P-25 could not. The absorptivity decreased sequentially as the wavelength increased from 400 to 700 nm. Within 6 h of 2-W blue-light illumination, 23% of 0.1 mM 2-chlorophenol was removed. The XRD result showed that the crystalline was anatase phase. The visible-light absorption property of the TiO2 became even better when doped with tungsten. At the optimum W to TiO2 ratio of 0.5%, the degradation of 0.1 mM 2-chlorophenol increased to 53% indicating a higher photocatalytic activity. Both crystalline and amorphous TiO2 could exhibit the photocatalytic activity under the visible light region.

Measurement and Characterization of CeO2-TiO2 Ion Storage Films for Electrochromic Devices

2017 ◽  
Vol 726 ◽  
pp. 276-281
Author(s):  
Wei Shan Wu ◽  
Xiao Ping Liang ◽  
Jun Wang ◽  
Peng Chen ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Optical Measurements ◽  
Molar Ratio ◽  
Nitrate Hexahydrate ◽  
Electrochromic Devices ◽  
Molar Ratios ◽  
Ion Storage ◽  
The Stability ◽  
Dip Coating Technique

CeO2-TiO2 sols and films were prepared by sol-gel method. The precursor sols consist of a mixture of cerium nitrate hexahydrate Ce(NO3)3·6H2O, butyl titanate Ti(OC4H9)4 and anhydrous ethanol CH3CH2OH. The films were deposited using the dip-coating technique and calcined at 310 °C in an oxygen atmosphere. The effects of the molar ratios of cerium to titanium（0.55:1, 0.70:1, 0.85:1, 1:1）on the microstructure and properties of (CeO2)x-TiO2 films were investigated. The surface morphology, electrochemical performance and optical property were characterized by FE-SEM, cyclic voltammetry (CV) and UV-Visible spectrometer, respectively. The results show that the properties of the films are tightly related to cerium to titanium ratio. When the molar ratio of cerium to titaniumis 0.85:1, the ion storage capacity value of CeO2-TiO2 film is 19.99mC/cm2, whereas the pure TiO2 film is 11.52mC/cm2. The stability tests and optical measurements confirm that the developed CeO2-TiO2 films can be use as ion storage-counter eletrodes in electrochromic devices.

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