scholarly journals Reforming Performance and Visible Light Responsibility of Cr-Doped Prepared by Sol-Gel and Dip-Coating Method

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Akira Nishimura ◽  
Go Mitsui ◽  
Masafumi Hirota ◽  
Eric Hu
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Sol Gel ◽  
Dip Coating ◽  
Layer Number ◽  
Coating Method ◽  
Dip Coating Method ◽  
Better Than

A Cr-doped film was prepared by sol-gel and dip-coating method and used as the photocatalyst for reforming under the visible light. The ratio of amount of Cr added to amount of Ti in sol solution (R) varied from 0 to 100 wt%. The total layer number of Cr-doped film (N) coated was up to 7. The reforming performance with the Cr-doped film was evaluated by illuminating under a Xe lamp with or without ultraviolet (UV) light. The concentration of CO which was a product from reforming was maximized for  wt% whenNequals to 1. The visible light responsibility was also maximized for  wt%. The amount of Cr within film coated on copper disc was increased with the increase inRup to 70 wt% and started to decrease whenRis over 70 wt%. The reforming performance of film with one layer Cr-doped was found better than that of film with multi Cr-doped layers under illuminating of UV light. Under the visible light, the performance was maximized at  wt% and with one layer Cr-doped.

Effect of ZnO on a Superhydrophilic Self-Cleaning Properties of TiO2/SiO2 Thin Film on Glass Slide Substrate

2015 ◽  
Vol 1131 ◽  
pp. 237-241 ◽  
Author(s):  
Akkarat Wongkaew ◽  
Chanida Soontornkallapaki ◽  
Naritsara Amhae ◽  
Wichet Lamai
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Visible Light ◽  
Band Gap ◽  
Sol Gel ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Coating Method ◽  
Dip Coating Method

This work aims to study the effect of ZnO containing in TiO2/SiO2 film on the superhydrophilic property after exposed to different types of light. The metal solutions were prepared by sol-gel technique and the film was deposited on glass slides by dip coating method. The parameter studied was the amount of ZnO in the TiO2/SiO2 film. The contents of ZnO were 5-20% weight (increased by 5%). The amount of TiO2 was constant at 30% weight. The obtained films were analyzed for their roughness. The results indicated that film roughness changed according to the ZnO contents. With 5%ZnO in the thin film, the roughness was 0.726 nm while 20%ZnO obtained the roughness of 2.128 nm. UV-Vis spectrophotometer was used for measuring of transmittance of films. At wavelength of 550 nm, the transmittances of each film were greater than 90%. Band gap energy of each film was calculated from the transmittance data. It was found that the average band gap energy of the films was 2.47 eV. Then, the films contained various amount of ZnO were grouped into 2 sets. The first set was exposed to visible light while the other set was exposed to UV. The duration of exposure was 5 hr. Both sets of films after exposed to any light were kept in a black box controlled relative humidity of 85%. Each film was measured contact angle every day. It was found that the 30%TiO2/5%Zn/SiO2 film exposed to visible light showed the best superhydrophilic property. The contact angle was about 0-5° within 3 days. This may due to the reduction of band gap energy in the presence of ZnO in TiO2/SiO2 films to 2.41 eV and the roughness of the film.

scholarly journals Sol-Gel Synthesis of TiO2/SiO2 and ZnO/SiO2 Composite Films and Evaluation of Their Photocatalytic Activity towards Methyl Green

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. L. Chandraboss ◽  
B. Karthikeyan ◽  
J. Kamalakkannan ◽  
S. Prabha ◽  
S. Senthilvelan
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Methyl Green ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Coating Method ◽  
Dip Coating Method

The TiO2/SiO2 and ZnO/SiO2 composite films were prepared by sol-gel dip coating method. The surface morphology and crystal structure of thin films were characterized by means of scanning electron microscopy (SEM) with elementary dispersive X-ray analysis (EDX) and X-ray diffractometer (XRD). Optical properties of films have been investigated using ultraviolet and visible spectroscopy (UV-visible spectroscopy). The photocatalytic activity was established by testing the degradation and decolorization of methyl green (MG) from aqueous solution with artificial UV-light.

Degradasi Gas Benzena Melalui Proses Pemangkinanfoto Saput Tipis TiO2

2012 ◽  
Author(s):  
Wan Azelee Wan Abu Bakar ◽  
Mohd Yusof Othman ◽  
Noor Khaida Wati Mohd Saiyudi ◽  
Keiichi Tanaka
Keyword(s):  
Thin Film ◽  
Light Source ◽  
Tio2 Thin Film ◽  
Uv Light ◽  
Wave Length ◽  
Sol Gel ◽  
Dip Coating ◽  
Optimum Ratio ◽  
Coating Method ◽  
Dip Coating Method

Pengoksidaanfoto benzena fasa gas menggunakan saput tipis TiO2 yang disinari lampu ultralembayung telah dikaji. Saput tipis ini disediakan melalui kaedah celup angkat menggunakan sol–gel TiO2. Tindak balas yang sama juga telah dijalankan menggunakan saput tipis TiO2 yang didop dengan Cu2+ dan Fe3+ dengan nisbah mol TiO2 terhadap ion logam 1:0.005, 1:0.001, 1:0.0005 dan 1:0.0003. Hasil kajian menunjukkan mangkin TiO2 dengan pancaran cahaya UV (354 nm) mendegradasikan gas benzena sebanyak 90% dalam masa 55 minit. Walau bagaimanapun penambahan ion Fe3+ dengan nisbah 1:0.0005 meningkatkan peratusan degradasi benzena kepada 98% dalam masa 55 minit, sebaliknya penambahan Cu2+memberikan kesan negatif kepada aktiviti foto TiO2. Kajian juga memperoleh satu nilai optimum dengan aktiviti pemangkinan adalah tertinggi bagi kedua-dua ion Fe3+ dan Cu2+. Pengaruh panjang gelombang cahaya ke atas aktiviti foto TiO2 juga telah dikaji dengan menggunakan mangkin TiO2 dop Fe3+ dengan nisbah optimum. Hasil kajian menunjukkan bahawa degradasi gas benzena meningkat dengan pengurangan tenaga cahaya yang dipancarkan. Kata kunci: Pemangkinanfoto; pengoksidaanfoto; saput tipis; TiO2 The gas phase photooxidation of benzene was investigated using TiO2 thin film irradiated with UV light source. The thin film was prepared via TiO2 sol gel dip coating method. The same reaction was also carried out using TiO2 doped with Cu2+ and Fe3+ with 1:0.005, 1:0.001, 1:0.0005 and 1:0.0003 mole ratios. The results showed that 90% of benzene was degraded after 55 minutes UV (354 nm) irradiation of the TiO2 thin film. However the addition of Fe3+ ions with 1:0.0005 mole ratio degraded 98% of benzene within 55 minutes. In contrast, Cu2+ ions however give a detrimental effect to the photoactivity of TiO2. An optimum ratio of dopant, where TiO2 showed the highest activity, was determined for both Fe3+ and Cu2+. The effect of different wave-length light source was also carried out using TiO2 doped Fe3+ with optimum ratio. The degradation of benzene was found to increase with decreasing light energy. Key words: Photocatalysis; photooxidation; TiO2 thin film

scholarly journals Photocatalytic Reactivity of Carbon–Nitrogen–Sulfur-Doped TiO2 Upconversion Phosphor Composites

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1188
Author(s):  
Seong-Rak Eun ◽  
Shielah Mavengere ◽  
Bumrae Cho ◽  
Jung-Sik Kim
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Dip Coating ◽  
Light Illumination ◽  
Doped Tio2 ◽  
Light Region ◽  
Coating Method ◽  
Dip Coating Method ◽  
Band Gap Narrowing ◽  
Impurity Sites

Sol–gel synthesized N-doped and carbon–nitrogen–sulfur (CNS)-doped TiO2 solutions were deposited on upconversion phosphor using a dip coating method. Scanning electron microscopy (SEM) imaging showed that there was a change in the morphology of TiO2 coated on NaYF4:Yb,Er from spherical to nanorods caused by additional urea and thiourea doping reagents. Fourier transform infrared (FTIR) spectroscopy further verified the existence of nitrate–hyponitrite, carboxylate, and SO42− because of the doping effect. NaYF4:Yb,Er composites coated with N- and CNS-doped TiO2 exhibited a slight shift of UV-Vis spectra towards the visible light region. Photodecomposition of methylene blue (MB) was evaluated under 254 nm germicidal lamps and a 300 W Xe lamp with UV/Vis cut off filters. The photodegradation of toluene was evaluated on TiO2/NaYF4:Yb,Er and CNS-doped TiO2/NaYF4:Yb,Er samples under UV light illumination. The photocatalytic reactivity with CNS-doped TiO2/NaYF4:Yb,Er surpassed that of the undoped TiO2/NaYF4:Yb,Er for the MB solution and toluene. Photocatalytic activity is increased by CNS doping of TiO2, which improves light sensitization as a result of band gap narrowing due to impurity sites.

Preparation and Photocatalytic Activity of Sol-Gel Method Derived La Doped TiO2/ITO Photocatalytic Electrodes

2012 ◽  
Vol 452-453 ◽  
pp. 486-490
Author(s):  
Wei Fu Wang ◽  
Cheng Ling Hu ◽  
Ming Yi Chang ◽  
Yung Hsu Hsieh
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Dip Coating ◽  
Tio2 Thin Films ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ito Glass ◽  
Coating Method ◽  
Dip Coating Method ◽  
La Doped

La–doped TiO2 thin films were synthesized using TTIP, IPA , Acetic acid ,and La2¬O3 as precursors by sol-gel method and dip-coating method. The different molar raitos of La/Ti ( 0.025,0.050,0.075 and 0.100 ) were supported on ITO glass to product photocatalytic electrodes. The properties of both TiO2/ITO and La- TiO2/ITO photocatalytic electrodes were characterized by FE-SEM,BET and XRD. The FE-SEM and BET analytical results demonstrate that La-TiO2/ITO particles have uniform shape and small size (＜10nm ) compared with TiO2/ITO. Anotherway, the XRD resultes show that when more molar raitos of La/Ti the crystallites become more percent to of rutile. The La-TiO2/ITO photocatalytic electrode with molar raito 0.05 shows the best photocatalysis with mineralization rate after four hours reaction. On this condition, different Acid Yellow 17 initial concentration and UV light intensity have been research. Applied potential 2.0V would effectively increase the decolonization rate under visible light irradiation.

scholarly journals Visible Light Excited Catalysis and Reusability Performances of TiO2@Pr:Y2SiO5 Upconversion Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Jiao ◽  
Yamiao Wang ◽  
Min Li ◽  
Ying Liu ◽  
Ping Mao ◽  
...  
Keyword(s):  
Visible Light ◽  
Glass Fiber ◽  
High Efficiency ◽  
Treatment Time ◽  
Sol Gel ◽  
Dip Coating ◽  
Photodegradation Rate ◽  
Coating Method ◽  
Dip Coating Method ◽  
First Time

To get high efficiency photodegradation on pollutants under visible light, Pr(III) doped Y2SiO5 upconversion materials and anatase TiO2 nanofilm coated Pr:Y2SiO5 composite have been prepared by using a sol-gel method. XRD and SEM test results indicated that TiO2 nanofilm was well coated on Pr:Y2SiO5 to form TiO2@Pr:Y2SiO5 composite particles with the sizes of 0.5–1.0 μm. To avoid secondary pollution resulting from incomplete recovery of catalyst particles, TiO2@Pr:Y2SiO5 was loaded on the glass fiber filters by using a dip-coating method. It is found that the catalyst particles were embedded into the carrier firmly, even after having been reused for 6 times. The luminescence intensities of TiO2@Pr:Y2SiO5 were getting down sharply with the coating contents of TiO2 increased, which was attributed to the adsorption of the luminescence by the TiO2 film in situ. As a result, TiO2@Pr:Y2SiO5 with 4% TiO2, which presented lowest luminescence intensity, showed the highest efficiency on the photodegradation of nitrobenzene wastewater. The catalysts loaded on glass fiber filters showed excellent reusability on the photodegradation of nitrobenzene and presented a photodegradation rate of 95% at the first time and up to 75.9% even after 6 times of reusing by the treatment time of 12 h.

Porous Gel Coatings Obtained by Phase Separation in ORMOSIL System

2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai
Keyword(s):  
Phase Separation ◽  
Reaction Time ◽  
Volume Fraction ◽  
Sol Gel ◽  
Reaction Times ◽  
Dip Coating ◽  
Coating Solution ◽  
Coating Method ◽  
Gel Phase ◽  
Dip Coating Method

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.

Synthesis of WO3 Electrochromic Sensor by Sol-Gel Method and Characterization of Its Electrochemical and Optical Properties

2006 ◽  
Vol 317-318 ◽  
pp. 807-810 ◽  
Author(s):  
Chang Yeoul Kim ◽  
Jin Wook Choi ◽  
Tae Yeoung Lim ◽  
Duck Kyun Choi
Keyword(s):  
Thin Film ◽  
Sol Gel ◽  
Dip Coating ◽  
Xrd Pattern ◽  
Starting Solution ◽  
Oxide Crystal ◽  
Heat Treated ◽  
Coating Method ◽  
Dip Coating Method

Electrochromic WO3 thin film was prepared by using tungsten metal solution in hydrogen peroxide as a starting solution and by sol-gel dip coating method. XRD pattern showed that tungsten oxide crystal phase formed at 400. In the view of electrochemical property, WO3 thin film which was heat-treated at 300 and was amorphous had better than that of the crystalline phase.

Optical, magnetic and structural properties of Cr-doped ZnO thin films by sol–gel dip-coating method

2017 ◽  
Vol 4 (9) ◽  
pp. 096403 ◽  
Author(s):  
Zohra N Kayani ◽  
Marya Siddiq ◽  
Saira Riaz ◽  
Shahzad Naseem
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
Zno Thin Films ◽  
Coating Method ◽  
Doped Zno ◽  
Dip Coating Method
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