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

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.

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Rigoberto Regalado-Raya ◽  
Rubí Romero-Romero ◽  
Osmín Avilés-García ◽  
Jaime Espino-Valencia

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.


2014 ◽  
Vol 608 ◽  
pp. 164-169
Author(s):  
Peerawas Kongsong ◽  
Lek Sikong ◽  
Sutham Niyomwas ◽  
Vishnu Rachpech

The Fe3+ and N–doped 3SnO2/TiO2 composite thin films and undoped films coated on glass fibers were prepared by sol–gel and dip–coating methods. The films were calcined at 600°C for 2 hour and characterized by XRD, SEM, EDS and XPS. The photocatalytic activity of the coated glass fibers was determined by means of degradation of a methylene blue (MB) solution and humic acid (HA). It was found that the optimized 20N/3SnO2/TiO2composite films exhibit a high photocatalytic activity and HA could be rapidly removed from water. The main factor affecting the HA degradation of 20N/3SnO2/TiO2 films is quantity of glass fibers loading, irradiation power of UV lamp and flow rate of water.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. L. Chandraboss ◽  
B. Karthikeyan ◽  
J. Kamalakkannan ◽  
S. Prabha ◽  
S. Senthilvelan

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.


2012 ◽  
Vol 18-19 ◽  
pp. 165-176 ◽  
Author(s):  
J.O. Carneiro ◽  
V. Teixeira ◽  
S. Azevedo ◽  
F. Fernandes ◽  
J. Neves

Urbanism and communities centralization enlarges atmospheric pollution that affects both human beings as well as their constructed buildings. Different scientific and technological studies are being conducted, both in academic and construction industry, aiming the development of new construction materials with properties that can decrease visual pollution of cities, reducing also the number of cleanings required. The present research work aims the study and the production of self-cleaning ceramic surfaces in an economical and viable way without changing aesthetical aspect of material substrates used. The use of TiO2 nanoparticles (TiO2-NNPs) represents an attractive way to generate self-cleaning surfaces, therefore promoting the degradation of pollutant agents and reducing cleaning maintenance costs. In order to impart self-cleaning properties to ceramic surfaces, TiO2-NNPs based layers were deposited on different ceramic material substrates using the dip-coating method. The Photocatalytic activity (degradation of pollutants adsorbed on the surface) of the TiO2-NNPs based layers was characterized via the decomposition rate of an aqueous solution of Methylene blue (MB) under UV light irradiation. Colourless layers were successfully produced onto gray and white ceramic substrates using this sol-gel technique, without changing their aesthetical appearance. It was observed that the best photocatalytic activity was exhibited by the most porous ceramic substrate (gray); nevertheless, all the TiO2-NNPs coated ceramic surfaces showed good photocatalytic efficiency.


2014 ◽  
Vol 979 ◽  
pp. 90-93 ◽  
Author(s):  
Weerachai Sangchay ◽  
Tanarat Rattanakool

The pure TiO2and SnO2-TiO2thin films on glass substrate were fabricated using a sol-gel dip coating technique. The thin films were annealed at the temperature of 700 °C for 2 h with the heating rate of 10 °C/min. The microstructures of the fabricated thin films were characterized by SEM and XRD techniques. The photocatalytic activities of the thin films were also tested by the degradation of methylene blue (MB) solution under UV irradiation. Finally, hydrophilic or self-cleaning properties of thin films were evaluated by measuring the contact angle of water droplet on the thin films with and without UV irradiation. It was found that 1 %mol SnO2-TiO2thin films shows the highest of photocatalytic activity and provide the most self-cleaning properties.


2003 ◽  
Vol 10 (04) ◽  
pp. 635-640 ◽  
Author(s):  
C.-K. Jung ◽  
S.-H. Cho ◽  
S.-B. Lee ◽  
T.-K. Kim ◽  
M.-N. Lee ◽  
...  

We have deposited titanium dioxide TiO 2 thin films on glass using a single molecular precursor such as titanium (IV) isopropoxide ( Ti [ OCH ( CH 3)2]4, 97%) by sol–gel processing. Argon and oxygen rf plasma treatments at 295 K for 0.5 h in the power range of 50–200 W were also used to elevate photocatalytic activity of the as-grown TiO 2 films. A superhydrophilic property and surface morphology change appeared in the light irradiation with O 2 plasma treatment. In this work, the effect of the plasma with photocatalyst ( TiO 2) on the improvement of hydrophilic properties has mainly been investigated. Photocatalytic activity was evaluated by measurements of the uv/vis. irradiation, refractive index, contact angle, and AFM analysis. We confirmed that plasma treatment is a very reliable method for the synthesis of TiO 2 thin films with high catalytic performance.


Sign in / Sign up

Export Citation Format

Share Document