scholarly journals Synthesis and Characterization of TiO2/SiO2 Monoliths as Photocatalysts on Methanol Oxidation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Rigoberto Regalado-Raya ◽  
Rubí Romero-Romero ◽  
Osmín Avilés-García ◽  
Jaime Espino-Valencia
Keyword(s):  
Thin Film ◽  
Methanol Oxidation ◽  
Immersion Time ◽  
Film Formation ◽  
Anatase Phase ◽  
Sol Gel ◽  
Packed Bed ◽  
Dip Coating ◽  
Packed Bed Reactor ◽  
Titanium Butoxide

Photocatalytic materials based on silica-titania (SiO2-TiO2) were synthesized by sol-gel and dip-coating method. TEOS and titanium butoxide were used as precursors of the silica-titania, respectively. A thin film with anatase phase was obtained on the surface of the support. The effect of variables as dispersion mechanism, immersion time, and number of treatment cycles were studied. The materials were characterized using X-ray diffraction, scanning electron microscopy, energy dispersion scanning, and N2 adsorption-desorption. The highest crystallinity of TiO2 on silica, high specific surface area in TiO2-SiO2 materials, and thin film formation were obtained by using a stirring plate and minimum immersion time. The so synthesized catalyst allowed the production of formaldehyde from the photocatalyzed methanol oxidation in a packed-bed reactor.

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.

Preparation TiO2 Thin Films Using Freeze Drying Technique

2011 ◽  
Vol 239-242 ◽  
pp. 2738-2741
Author(s):  
Hai Bo Wang ◽  
Xiang Chao Zhang ◽  
Li Chen
Keyword(s):  
Thin Film ◽  
Freeze Drying ◽  
Anatase Phase ◽  
Sol Gel ◽  
Spherical Shape ◽  
Average Diameter ◽  
Dip Coating ◽  
Differential Scanning Calorimetric ◽  
Glass Substrates ◽  
Process Route

Titanium dioxide (TiO2) thin film has been successfully synthesized deposited on glass substrates by the sol–gel dip-coating method using freeze drying technique. The precursor and TiO2 film were characterized using thermogravimetric and differential scanning calorimetric (TG-DSC), X-ray diffraction (XRD) and atomic force microscopy (AFM) analysis technology. The preparation of the precursor sols and TiO2 film were described in detail. The XRD result demonstrates that the TiO2 film is well crystallized and consists of anatase phase only with (101) plane. The morphology of the nanoparticles of TiO2 thin film is spherical shape with grain size of 30.1 nm in average diameter and the surface of the TiO2 film is smooth. The freeze drying technique offers a novel process route in treating thin film for commercial applications

scholarly journals Effect of titanium source and sol-gel TiO2 thin film formation parameters on its morphology and photocatalytic activity

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Piotr Dulian ◽  
Jan Zajic ◽  
Witold Żukowski
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Surface Structure ◽  
Uv Light ◽  
Film Formation ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Dip Coating ◽  
Single Step ◽  
Titanium Butoxide

AbstractTiO2 thin films with different surface structure have been prepared from alkoxide solutions by the sol-gel method using different cationic precursors and heat treatment techniques. The effect of using titanium isopropoxide as well as titanium butoxide as a titanium source on the surface structure and photocatalytic activity of the resultant thin films was studied. Significant differences in the rate of hydrolysis and condensation reactions during the sol-gel synthesis were observed for these titanium precursors. This had a direct influence on the morphology of the as-prepared TiO2 films. Higher quality oxide coatings were obtained from titanium isopropoxide. They were characterized by a smaller grain size, improved surface roughness and uniform coverage of the glass substrate. A beneficial effect of calcination process after each sol application cycle in contrast to single step calcination after all dip-coating cycles was observed. Photocatalytic degradation tests showed that methyl orange was decolorized in the presence of all prepared TiO2 films by exposing their aqueous solutions to UV light (λ = 254 nm). The highest photocatalytic activity had the TiO2 layer produced using titanium isopropoxide.

Preparation and Characterization of TiO2 Photocatalytic Thin Film Prepared by Sol-Gel Dip Coating

2012 ◽  
Vol 476-478 ◽  
pp. 2398-2402
Author(s):  
Jiao Jiao Wang ◽  
Kai Zheng ◽  
Christian Rüssel ◽  
Wen Liang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Rhodamine B ◽  
Uv Light ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Dip Coating ◽  
High Photocatalytic Activity ◽  
Tio2 Thin Films

Titanium dioxide thin films have been prepared from tetrabutyl-orthotitanate solution and methanol as a solvent by sol-gel dip coating technique. The thermal properties of TiO2 gel were analyzed by thermogravimetry and differential thermal analysis (TG-DTA). Structural properties of TiO2 thin films at different heat treatment temperatures were analyzed by X-ray diffraction (XRD), Infrared Raman spectroscopy and scanning electron microscopy (SEM). The results show that the TiO2 thin films crystallize in anatase phase at 400 °C and the crystallinity of anatase phase was improved with increasing temperature. The TiO2 thin films crystallize into the anatase-rutile phase at 600 °C and further into the rutile phase at 800 °C. The photocatalytic performance of TiO2 film was tested for the degradation of 2×10-5 mol/L Rhodamine B. The degradation of Rhodamine B solutions reached 0.9×10-5 mol/L after irradiated for 8 h under UV light. The TiO2 thin film exhibited relatively high photocatalytic activity towards degrading Rhodamine B.

Numerical simulation of the liquid phase in SnO2 thin film deposition by sol-gel-dip-coating

2010 ◽  
Vol 55 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Dayene M. Carvalho ◽  
Jorge L. B. Maciel ◽  
Leandro P. Ravaro ◽  
Rogério E. Garcia ◽  
Valdemir G. Ferreira ◽  
...  
Keyword(s):  
Thin Film ◽  
Numerical Simulation ◽  
Liquid Phase ◽  
Sol Gel ◽  
Thin Film Deposition ◽  
Dip Coating ◽  
Film Deposition ◽  
Sno2 Thin Film

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.

scholarly journals Visible emission from Er-doped SnO2 thin films deposited by sol-gel

Cerâmica ◽  
2007 ◽  
Vol 53 (326) ◽  
pp. 187-191 ◽  
Author(s):  
L. P. Ravaro ◽  
E. A. Morais ◽  
L. V. A. Scalvi ◽  
M. Siu Li
Keyword(s):  
Thin Film ◽  
Electric Fields ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Precursor Solution ◽  
Dip Coating ◽  
Sno2 Thin Film ◽  
Rare Earth Ion ◽  
Electron Hole ◽  
Er Doped

Emission from Er-doped SnO2 thin film deposited via sol-gel by the dip coating technique is obtained in the range 500-700 nm with peak at 530 nm (green). Electron-hole generation in the tin dioxide matrix is used to promote the rare-earth ion excitation. Evaluation of crystallite dimensions through X-ray diffraction results leads to nanoscopic size, what could play a relevant role in the emission spectra. The electron-hole mechanism is also responsible for the excitation of the transition in the 1540 nm range in powders obtained from the same precursor solution of films. The thin film matrix presents a very useful shape for technological application, since it allows integration in optical devices and the application of electric fields to operate electroluminescent devices.

Synthesis and Film Investigation of Titania

2013 ◽  
Vol 832 ◽  
pp. 128-131
Author(s):  
Sharipah Nadzirah ◽  
Uda Hashim
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Titanium Dioxide ◽  
Sol Gel ◽  
Titanium Butoxide ◽  
Before And After ◽  
Scanning Electron ◽  
Spin Coater

Titania or titanium dioxide (TiO2) thin film has been synthesized via sol-gel method with monoethanolamine (MEA) as a catalyst. The mixing of titanium butoxide as a precursor, ethanol as a solvent and MEA were stirred using magnetic stirrer under ambient temperature [. The TiO2solution prepared then was deposited on SiO2substrates using spin-coater and the coated films were annealed at 600°C. Finally, both before and after annealed TiO2thin films were characterized using Field Emission Scanning Electron Microscopy (FESEM). The obtained results show the different TiO2particles formation before and after annealed.

Solar-Water-Splitting BiVO4 Thin-Film Photoanodes Prepared By Using a Sol-Gel Dip-Coating Technique

ChemPhotoChem ◽  
2017 ◽  
Vol 1 (6) ◽  
pp. 273-280 ◽  
Author(s):  
Samantha Hilliard ◽  
Dennis Friedrich ◽  
Stéphane Kressman ◽  
Henri Strub ◽  
Vincent Artero ◽  
...  
Keyword(s):  
Thin Film ◽  
Water Splitting ◽  
Sol Gel ◽  
Dip Coating ◽  
Solar Water ◽  
Coating Technique ◽  
Solar Water Splitting ◽  
Dip Coating Technique

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.

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