Preparation of porous titania thin film and its photocatalytic activity

doi:10.1016/j.apsusc.2008.08.102

Applied Surface Science

Volume 255, Issue 5, Part 2, 30 December 2008, Pages 3137-3140

https://doi.org/10.1016/j.apsusc.2008.08.102 Get rights and content

Abstract

In this study, different titania films were prepared by a sol–gel spin-coating technique. By introducing nanocarbon spheres into the precursor solution, porous titania film was prepared after calcination at a temperature of 500 °C for 3 h. The as-prepared porous titania film was characterized by XRD, BET, TEM and SEM. The photocatalytic property of the prepared porous film was evaluated by degrading X-3B under UV irradiation. Results showed that photocatalytic performance of as-prepared porous film was much higher than that of smooth titania and P25 films.

Introduction

Anatase-phase titania has attracted extensive attention during the last few decades due to its excellent photocatalytic properties [1], [2], [3], [4], [5]. However, TiO₂ with high photoactivity and a significant quantum effect is commonly in nanometer size. The problem of separation and recovery of photocatalyst from the reaction medium exists, which enhances the overall capital and running cost of the treatment. Aggregation of photocatalyst would also decrease its photocatalytic activity in slurry system. So immobilized photocatalyst is more suitable for the practical application of titania photocatalysis, which has been given high attention in recent years. However, there is another problem that limitation of mass transfer often occurs [6] and activity of immobilized titania system is lower than slurry system. In order to improve photocatalytic performance, efforts have been made to increase the number of attainable surface activation sites by making porous mirostructure [7], [8], [9], [10], [11], [12].

In this study, we investigated the feasibility of preparing porous titania films using nanocarbon spheres pore-forming materials by a sol–gel spin-coating method. The photocatalytic properties of these films were evaluated by degrading Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under UV light irradiation.

Section snippets

Preparation of carbon spheres

In a typical synthesis of colloidal carbon spheres, 6 g of glucose was dissolved in 60 mL of water to form a clear solution. The solution was then sealed in a 50-mL Teflon-lined autoclave and maintained at 180 °C for 3 h. The products were then centrifuged, washed, and redispersed in water and ethanol for five cycles, respectively. Afterwards, the formed carbon spheres were then dried at 80 °C for 2 h under vacuum.

Preparation of porous titania film

The titania precursor sols were prepared by sol–gel method at low temperature. The

Characterization of the porous titania film

The X-ray diffraction (XRD) analysis pattern in Fig. 1 shows the titania phases formed at temperature 500 °C. The fact that the peaks are very narrow, indicate that the titania particles of the porous film are crystalline. As also shown in the figure, the particles had formed anatase-phase since the characteristic diffraction peaks of anatase (major peaks: 25.4°, 38.0°, 48.0°, 54.7°, and 63.1°) were evident in the sample. The calcination at 500 °C not only removed the carbon spheres, but also

Conclusions

Porous titania film was prepared by a simple method. Firstly, nanocarbon spheres were synthesized by hydrothermal method using glucose as precursor. The carbon spheres were used as pore-forming materials by a sol–gel coating technique. The photocatalytic property of the prepared porous film was evaluated by degrading X-3B under UV irradiation. Results showed that photocatalytic performance of as-prepared porous film was much higher than that of corresponding smooth films.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 60121101) and Joint Project of Guangdong Province and Education Department (No. 2007A090302018).

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Preparation of porous titania thin film and its photocatalytic activity

Abstract

Introduction

Section snippets

Preparation of carbon spheres

Preparation of porous titania film

Characterization of the porous titania film

Conclusions

Acknowledgements

Appl. Catal. B

Mater. Lett.

Thin Solid Film

Micropor. Mesopor. Mater.

Thin Solid Film

Appl. Surf. Sci.

Colloid Surf. A