Self-Organization in Nanoparticle Titanium Dioxide Thin Films

1998 ◽  
Vol 519 ◽  
Author(s):  
S.D. Burnside ◽  
V. Shklover ◽  
C.A. Barbe ◽  
K. Brooks ◽  
P. Comte ◽  
...  

AbstractNanocrystalline titanium dioxide has been synthesized using a sol-gel technique followed by hydrothermal growth at temperatures in the range 190-270°C. Thin films of these colloids were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption/desorption. Self-organization of the nanocrystalline particles in regular arrays was observed in films made from colloids autoclaved at lower temperatures. We present herein initial photovoltaic performance of these semiconducting films used as working electrodes in a dye-sensitized solar cell.

Author(s):  
Sunil Rawal ◽  
Sabrina H. Buer ◽  
Wayne Hawkins ◽  
Jonathan Robby Sanders ◽  
Pedro E. Arce

Abstract The utilization of titanium dioxide (TiO2) photocatalysis for water and air purification is a frequently used method due to TiO2 having properties making it chemically inert, highly cost-effective, abundant, non-toxic, and environmentally-friendly. In an effort to increase the efficiency of the degradation process, an in-depth understanding of the effects of the structure and number of thin film coatings is needed. Transparent, anatase-form titanium dioxide thin films were prepared via the sol-gel method and deposited onto microscopic glass slides using a novel spraying technique, with coatings ranging from 1 to 10. Characterization of the TiO2 thin film coated slides was performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The contribution shows that the coating technique is efficient in covering important areas of the surface and that it is suitable for a multiple coating layers thin film. The SEM imagines show that the surface of the slides increase coverage as the number of layers increases. This is potentially suitable for a mechanized spraying approach to upscaling the production of thin films for advanced oxidation applications.


2012 ◽  
Vol 16 ◽  
pp. 105-111 ◽  
Author(s):  
Raouf Mechiakh ◽  
R. Gheriani ◽  
R. Chtourou

Titanium dioxide thin films have been prepared by the sol–gel dip-coating method on an ITO substrate. The samples obtained were characterized by different experimental techniques: XRD, Raman, FTIR, spectroscopy of the electrochemical potential and SEM. The X-ray diffraction results showed that the TiO2 thin film obtained for a layer, after a temperature of annealing (400°C) and at the speeds of steeping between 2 and 10 cm∙s-1 was amorphous, and transformed into anatase–brookite at 0.6 cm∙s-1 for 400°C. The data of Raman spectroscopy is in good agreement with the DRX results. Observation by scanning electron microscope shows that the coating was transparent and homogeneous without any visual cracking over a wide area, and the increase in the treatment temperature did not affect the uniformity of the film. The interface of our layers to behaved like a n-type semiconductor.


Author(s):  
Anusuya Sahoo ◽  
A R Jayakrishnan ◽  
K Kamakshi ◽  
J P B Silva ◽  
K C Sekhar ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.


Sign in / Sign up

Export Citation Format

Share Document