scholarly journals Influence of the number of layers on photocatalysis activity of TiO2 thin films

2018 ◽  
Vol 7 (2) ◽  
pp. 88-97
Author(s):  
Abderhamane Boutelala ◽  
Fouzia Bourfaa ◽  
Mohamed Mahtali

Titanium oxide (TiO2) is one of the most important semiconductors because of their properties. This study was carried out to investigate the influence of the number of layers of Co -doped TiO2 thin films obtained by sol–gel method on the photocatalytic activity. The crystalline structure of films is characterised by means of X-ray diffraction and Raman spectroscopy. All the films were of anatase phase and the particle size was in nanoscale. The surface morphology was studied by atomic force microscopy. The optical properties were investigated by UV-visible spectroscopy. The photocatalytic properties of the samples were tested on the degradation of methylene blue dye solution. The results indicated that photocatalysis is more important when the number of dipping of films increases.Keywords: Photocatalysis, X-ray diffraction, TiO2, thin films, methylene blue.

2012 ◽  
Vol 490-495 ◽  
pp. 3306-3310
Author(s):  
Fei Gao ◽  
Xiao Yan Liu ◽  
Li Yun Zheng ◽  
Mei Xia Li ◽  
Rui Jiao Jiang

TiO2 and Ni-doped TiO2 thin films were prepared by DC magnetron sputtering. The effects of Ni-doping on the microstructure and properties were studied by atomic force microscopy (AFM), X-ray diffraction (XRD), UV-Vis spectra and photocatalysis tesing, respectively. The results show that TiO2 thin films were successfully prepared with smooth surface. When doped with Ni, the surface of TiO2 thin film was improved and the growth of anatase phase was also promoted. With increasing the sputtering power of Ni, the absorption edge wavelegth red shifted and the photocatalysis property of TiO2 thin films was increased and then decreased


2010 ◽  
Vol 150-151 ◽  
pp. 707-710
Author(s):  
Dan Hong Wang ◽  
Xiao Ru Zhao ◽  
Hui Nan Sun ◽  
Li Bing Duan ◽  
Chang Le Chen

The sol-gel method was employed to prepare the Eu3+-doped TiO2 thin films. The influence of doping concentration and annealing temperature on the structures and photoluminescence (PL) properties was investigated. The result of X-ray diffraction revealed that all the films are of anatase phase. It is shown that the PL intensities of the films increased with Eu3+ concentration and reached the maximum at 1.4 mol%, then decreased with the concentration. Observed anatase phase appeared at temperature above 400 °C, and the luminescence intensity increased with the increase of annealing temperature.


Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.


2012 ◽  
Vol 151 ◽  
pp. 314-318
Author(s):  
Ching Fang Tseng ◽  
Cheng Hsing Hsu ◽  
Chun Hung Lai

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various preheating temperatures and annealing temperatures. Particular attention will be paid to the effects of a thermal treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of treatment film were examined by scanning electron microscopy and atomic force microscopy. At a preheating temperature of 300oC and an annealing temperature of 700oC, the MgAl2O4 films with 9 μm thickness possess a dielectric constant of 9 at 1 kHz and a dissipation factor of 0.18 at 1 kHz.


2005 ◽  
Vol 19 (01n03) ◽  
pp. 671-673
Author(s):  
PENG XIAO ◽  
WANLU WANG

The Fe 3+- TiO 2 thin films obtained through sol-gel method were characterized by x-ray diffraction, AFM and Raman spectroscopy. It was found that TiO 2 films consisted of nanometer particles. The experimental results shows that the nanometer TiO 2 thin films doped with Fe 3+ were greatly improved in the activity aspect. This may be ascribed to change their structure and electrical properties after doping with Fe 3+. The results were discussed theoretically in detail.


2021 ◽  
Vol 21 (2) ◽  
pp. 279
Author(s):  
Nur Munirah Safiay ◽  
Rozina Abdul Rani ◽  
Najwa Ezira Ahmed Azhar ◽  
Zuraida Khusaimi ◽  
Fazlena Hamzah ◽  
...  

In this research, TiO2 thin films were prepared using a simple sol-gel spin coating process. The films were characterized using Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Ray (EDX), X-ray diffraction (XRD) and Ultraviolet–visible Spectrophotometer in order to investigate the influence of different annealing temperatures to the structural and optical properties of TiO2. The surface morphology images from FE-SEM display a uniform layer of nanoparticles with a sample of 500 °C possess the most uniform and the visible spherical grain of TiO2 nanoparticles. EDX spectra confirm the presence of Ti and O elements in the samples. The structural properties from the XRD pattern demonstrate that the films are crystalline at a temperature of 500 and 600 °C and the peak (101) intensity was increased as the annealing temperature increased. They exist in the anatase phase at the preferred plane orientation of (101). The calculated crystallite size for 500 and 600 °C samples is 19.22 and 28.37 nm, respectively. The films also possessed excellent absorption in the ultraviolet (UV) region with optical band gap energy ranging from 3.32 to 3.43 eV. These results can be fundamental for the fabrication of a UV sensing device.


2008 ◽  
Vol 8 (8) ◽  
pp. 4231-4237 ◽  
Author(s):  
Madhavi Thakurdesai ◽  
T. Mohanty ◽  
J. John ◽  
T. K. Gundu Rao ◽  
Pratap Raychaudhuri ◽  
...  

Nanodimensional TiO2 has wide application in the field of photocatalysis, photovoltaic and photochromic devices. In present investigation TiO2 thin films deposited by pulsed laser deposition method are irradiated by 100 MeV Ag ion beam to achieve growth of nanophases. The nanostructure evolution is characterized by atomic force microscopy (AFM). The phases of TiO2 formed after irradiation are identified by glancing angle X-ray diffraction and Raman spectroscopy. The particle radius estimated by AFM varies from 10–13 nm. Anatase phase of TiO2 is formed after irradiation. The blue shift observed in UV-VIS absorption spectra indicates the nanostructure formation. The shape and size of nanoparticles formed due to high electronic excitation depend upon thickness of the film.


2011 ◽  
Vol 1352 ◽  
Author(s):  
Marcelo M. Viana ◽  
Nelcy D. S. Mohallem

ABSTRACTColloidal precursor solutions, obtained from a mixture of titanium isopropoxide, isopropyl alcohol and silver nitrate, were used to fabricate amorphous TiO2 and Ag/TiO2 thin films by sol-gel process. The films were deposited on borosilicate substrates, which were heated at 400 °C for 30 minutes and cooled rapidly to the formation of amorphous coatings. The films were investigated by X-ray diffraction, scanning electron microscopy, atomic force microscopy and UV-vis spectroscopy. The thickness, roughness, refraction index, and particle size of the TiO2 and Ag/TiO2 films were determined and compared. Finally, hydrophobic-hydrophilic property was evaluated to the thin films produced.


2018 ◽  
Author(s):  
azadeh ebrahimian pirbazari ◽  
Pejman Monazzam ◽  
Behnam Fakhari Kisomi

In this work, TiO2 nanoparticles containing different amounts of cobalt were synthesized by sol-gel method using titanium (IV) isopropoxide and cobalt chloride as titanium and cobalt precursors, respectively. X-ray diffraction (XRD) results showed prepared samples include 100% anatase phase. The presence of cobalt in TiO2 nanoparticle network was established by XRD, scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM-EDX), Fourier transform infrared (FT-IR) and N2 physisorption techniques. The increase of cobalt doping enhanced redshif in the diffuse reflectance spectra. The photocatalytic activity of the prepared samples was tested for degradation of methylene blue (MB) as a model of dye. Although the photocatalytic activity of pure TiO2 was found to be higher than that of Co/TiO2 samples under UV irradiation, the presence of 0.24% cobalt dopant in TiO2 nanoparticles resulted in a photocatalyst with the highest activity under visible light


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
D. A. Solís-Casados ◽  
L. Escobar-Alarcón ◽  
V. Alvarado-Pérez ◽  
E. Haro-Poniatowski

The synthesis of Bi-modified TiO2 thin films, with different Bi contents, is reported. The obtained materials were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), X-ray diffraction (XRD), photoluminescence (PL), and diffuse reflectance spectroscopy (DRS), in order to obtain information on their chemical composition, vibrational features, and optical properties, respectively. Compositional characterization reveals that the bismuth content can be varied in an easy way from 0.5 to 25.4 at. %. Raman results show that the starting material corresponds to the anatase phase of crystalline TiO2, and Bi addition promotes the formation of bismuth titanates, Bi2Ti2O7 at Bi contents of 10.4 at. % and the Bi4Ti3O12 at Bi contents of 21.5 and 25.4 at. %. Optical measurements reveal that the band gap narrows from 3.3 eV to values as low as 2.7 eV. The photocatalytic activity was tested in the degradation reaction of the Malachite Green carbinol base dye (MG) as a model molecule under simulated sunlight, where the most relevant result is that photocatalytic formulations containing bismuth showed higher catalytic activity than pure TiO2. The higher photocatalytic activity of MG degradation of 67% reached by the photocatalytic formulation of 21.5 at. % of bismuth is attributed to the presence of the crystalline phase perovskite-type bismuth titanate, Bi4Ti3O12.


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