scholarly journals Effect of molarity on sol–gel routed nano TiO2 thin films

2017 ◽  
Vol 07 (06) ◽  
pp. 1750042 ◽  
Author(s):  
Stephen Lourduraj ◽  
Rayar Victor Williams

The nanostructured titanium dioxide (TiO[Formula: see text] thin films have been prepared for the molar concentrations of titanium tetra isopropoxide (TTIP) 0.05[Formula: see text]M, 0.1[Formula: see text]M, 0.15[Formula: see text]M and 0.2[Formula: see text]M by sol–gel routed spin coating technique with calcination at 450[Formula: see text]C. The processing parameters such as, pH value (8), catalyst HCl (0.1[Formula: see text]ml), spin speed (3000[Formula: see text]rpm) and calcination temperature (450[Formula: see text]C) are optimized. The crystalline nature and surface morphology were analyzed by XRD, SEM and AFM analysis. The XRD results confirm that the films are crystalline with anatase phase, and are nanostructured. The SEM micrographs of the TiO2 film reveal the spherical nature of the particle. AFM analysis establishes that the uniformity of the TiO2 thin film was optimized at 0.2[Formula: see text]M. The optical measurements show that the transmittance depends on the molarity, and the optical band gap energy of TiO2 films is found to be inversely proportional to molarity. The I–V characteristics exhibit that the molarity strongly influences the electrical conductivity of the film. The results indicate that the significant effect of molarity on structural, optical and electrical properties of the nanostructured TiO2 thin films will be useful to photovoltaic application.

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.


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.


2010 ◽  
Vol 09 (04) ◽  
pp. 355-358 ◽  
Author(s):  
T. S. SENTHIL ◽  
M. THAMBIDURAI ◽  
N. MUTHUKUMARASAMY ◽  
R. BALASUNDARAPRABHU

TiO2 thin films have been deposited onto well cleaned glass substrates by sol–gel spin coating method. The prepared TiO2 films have been annealed at different temperatures (350°C, 450°C and 550°C). The structural properties of the films have been studied using X-ray diffraction method and High Resolution Transmission Electron Microscope (HRTEM). The as-deposited films have been found to be amorphous in nature. The crystalline quality has been observed to improve with annealing temperature. The annealed TiO2 films have been found to exhibit anatase phase. The optical properties have been studied using transmittance spectrum.


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.


2013 ◽  
Vol 678 ◽  
pp. 103-107 ◽  
Author(s):  
Arumugam Ranjitha ◽  
Natarajan Muthukumarasamy ◽  
Santhanam Agilan ◽  
Mariyappan Thambidurai ◽  
Rangasamy Balasundraprabhu ◽  
...  

Nanocrystalline TiO2 thin films were prepared by sol-gel dip coating method. The structural investigations were carried out using x-ray diffraction technique. Anatase TiO2 thin films with tetragonal phase were obtained and the grain size was observed to lie in the range of 21-25 nm. Analysis on the surface topography of prepared films have been carried out using atomic force microscopy (AFM). The band gap energy is calculated from the absorption spectra of TiO2 films and is found to lie in the range 3.3 to 3.7 eV.


2011 ◽  
Vol 25 (31) ◽  
pp. 4163-4166 ◽  
Author(s):  
M. T. SARODE ◽  
P. N. SHELKE ◽  
Y. B. KHOLLAM ◽  
S. R. JADKAR ◽  
B. B. KALE ◽  
...  

TiO 2 sol-gel thin films were deposited on glass substrates by dip coating method. Nanocrystalline TiO 2 thin films were prepared at 300°C. The effect of annealing temperature on optical properties of nanocrystalline TiO 2 thin films was studied. The films were characterized by different techniques: XRD, UV-visible spectroscopy, FTIR spectroscopy and FESEM. The characterization studies revealed that the films are crystallized as anatase phase and are nano-structured. The optical measurements were showed the indirect band gap between 3.31 and 3.35 eV with corresponding crystallite sizes between 8.9 and 3.7 nm at the temperatures 300, 400 and 500°C. The FESEM images of film were showed spherical nanocrystalline structure of TiO 2 particles with the crystallite sizes between 30 and 100 nm. It is also observed that refractive index of the film increases with increasing the annealing temperature. The smaller crystallite size gives larger band gap due to quantum size effects.


2010 ◽  
Vol 24 (08) ◽  
pp. 807-816 ◽  
Author(s):  
M. VISHWAS ◽  
SUDHIR KUMAR SHARMA ◽  
K. NARASIMHA RAO ◽  
S. MOHAN ◽  
K. V. ARJUNA GOWDA ◽  
...  

TiO 2 thin films have been deposited on glass and indium tin oxide (ITO) coated glass substrates by sol–gel technique. The influence of annealing temperature on the structural, morphological and optical properties has been examined. X-ray diffraction (XRD) results reveal the amorphous nature of the as-deposited film whereas the annealed films are found to be in the crystalline anatase phase. The surface morphology of the films at different annealing temperatures has been examined by atomic force microscopy (AFM). The in situ surface morphology of the as-deposited and annealed TiO 2 films has also been examined by optical polaromicrograph (OPM). TiO 2 films infatuated different structural and surface features with variation of annealing temperature. The optical studies on these films suggest their possible usage in sun-shielding applications.


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.


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.


2012 ◽  
Vol 476-478 ◽  
pp. 2398-2402
Author(s):  
Jiao Jiao Wang ◽  
Kai Zheng ◽  
Christian Rüssel ◽  
Wen Liang

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.


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