Characterization and Annealing Effects of Titanium Dioxide Films Prepared by a Sol-Gel Process

2009 ◽  
Vol 79-82 ◽  
pp. 891-894
Author(s):  
Shui Yang Lien

Titanium dioxide (TiO2) has received intense interest because of the numerous technical applications. In this work, the TiO2 thin films were deposited on Si substrates by spin coating from a TiO2 solution prepared by a sol-gel method. It was found that the TiO2 film properties strongly depended on the post annealing conditions. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometer (FTIR) were used to investigate the compositional and chemical states of the thermal-treated TiO2 samples. For the TiO2 samples annealed in atmosphere, the contents of -C and -OH bonds increased when the process temperature increased. From XPS measurement, the atomic concentrations of carbon and oxygen in the film are determined to be approximately 46% and 37%, respectively. However, for the samples annealed in oxygen, the contents of -C and -OH bonds were found to decrease when the anneal temperature increased. The concentrations of carbon and oxygen in the film were approximately 11% and 59%, respectively. To further investigate the behavior, the in-depth concentration profile of carbon was measured for the TiO2 samples under different etching time. It was found that the carbon concentration drastically decreased from 11% (surface) to 0.2% (near the interface). The result indicates that the pure TiO2 film could be obtained by sol-gel coating with a suitable annealing process.

2011 ◽  
Vol 356-360 ◽  
pp. 574-578
Author(s):  
Xiao Jing Li ◽  
Guan Jun Qiao ◽  
Jin Ren Ni

Nanometer titanium dioxide films supported on glass, quartz, molybdenum, and aluminum were prepared by sol-gel method. The loaded titanium dioxide films were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and photocatalytic degradation of aqueous crystal violet. The titanium dioxide films supported on different substrates were all composed of polycrystalline nanoparticles, which belonged to single-phase anatase, and displayed different morphology after sintering at 773 K for 1 h. Some elements in the substrate made of noncrystal appeared on the surface of titanium dioxide films. The experiment about basic crystal violet degradation displayed the photocatalysis activity of titanium oxide films supported on the molybdenum was better.


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 886 ◽  
Author(s):  
Hyeon Jin Seo ◽  
Ji Won Lee ◽  
Young Hoon Na ◽  
Jin-Hyo Boo

For environmental applications, such as water and air purification utilizing photocatalysts, we synthesized patterned titanium dioxide (TiO2) thin films using polystyrene (PS) spheres. This was primarily done to enhance the surface area and photocatalytic activities. TiO2 thin films were deposited on silicon wafers attached to variously sized PS spheres via the spin coating method and were annealed at 600 °C. The processing step involved patterning and coating a TiO2 sol–gel. The photocatalytic performance was analyzed using an UV–visible spectrophotometer. Within 20 min, a high catalytic efficiency (98% removal) with a 20-time faster decomposition rate of the malachite green (MG) solution than that of the nonpatterned TiO2 was obtained from the patterned TiO2 with 400 nm sized PS due to the large surface area. In addition, the phenol in the water removed as much as 50% within 2 h with the same photocatalyst, which was expected to be one of the strong candidates to be applied to the next generation of photocatalysts for water purification.


Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.


2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Marek Nocuń ◽  
Sławomir Kwaśny

AbstractIn our investigation, V doped SiO2/TiO2 thin films were prepared on glass substrates by dip coating sol-gel technique. Chemical composition of the samples was studied by X-ray photoelectron spectroscopy (XPS). Transmittance of the samples was characterized using UV-VIS spectrophotometry. Subsequently band-gap energy (Eg) was estimated for these films. Powders obtained from sols were characterized by FTIR spectroscopy. It was found that vanadium decreases optical band gap of SSiO2/TiO2 films.


Author(s):  
Hamid Dadvar ◽  
Farhad E. Ghodsi ◽  
Saeed Dadvar

In this chapter, the sol-gel made titanium dioxide nanostructured thin films deposited on special substrates such as glasses, mica, steels, textiles, fibers, and other organic/inorganic substrates were reviewed. Through this review, several distinctive properties such as optical, electrical, photocatalytic, morphological, and mechanical properties of TiO2 nanostructured thin films were described. Also, a wide range of practical application of TiO2 nanostructured thin films such as dye-sensitised solar cells, optical coatings, humidity and gas sensors, selfcleaning, dielectric, and antibacterial surfaces were discussed in details. Dip and spin coating techniques were demonstrated as suitable methods for deposition of thin films. It has been shown that properties of such films can be affected by type of coating technique, stabilizer, precursor material, solvents, pH and viscosity of precursor solution, aging, and etc. Finally, Successive Interference Fringes Method (SIFM) was presented as a simple method for the determination of optical constants and thickness of TiO2 thin films from single transmission measurements.


2009 ◽  
Vol 79-82 ◽  
pp. 1103-1106
Author(s):  
Hai Xia Hong ◽  
Yan Sheng Yin ◽  
Hong Feng Wang ◽  
Shou Gang Chen ◽  
Tao Liu ◽  
...  

Sol-gel TiO2 thin films undoped and doped with Ag-ions have been formed on 304ss by dip-coating method respectively. The Ag/TiO2 films are compact and have anatase phase with stable crystal structure and have a thickness of 50 nm approximately. The bactericidal rate of the Ag/TiO2 film against sulfate-reducing bacteria (SRB) strains reaches 97.1% when doping Ag+ with a percentage of 3%. The analysis of potentiodynamic polarization curves illustrates Ag/TiO2 film decreases the corrosion rate obviously.


2011 ◽  
Vol 76 (11) ◽  
pp. 1335-1346 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao

A series of copper-modified titanium dioxide (Cu/TiO2) nanoparticles were synthesized via one-step sol-gel method. The crystal structure and chemical properties were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Cu/TiO2nanoparticles were applied to CO2photoconversion and the yield of formaldehyde was used to evaluate the photocatalytic performance. The optimum amount of copper modifying was 0.6 wt.% and the yield of formaldehyde was 946 μmol/gcatunder UV illumination for 6 h. 20 wt.% Cu/TiO2also performed a high photocatalytic activity, which yielded 433 μmol/gcatformaldehyde under UV illumination for 6 h.


2007 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
Naoki Arimitsu ◽  
Akira Nakajima ◽  
Keisuke Saito ◽  
Yoshikazu Kameshima ◽  
Kiyoshi Okada

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