MesoporousTiO2Micro-Nanometer Composite Structure: Synthesis, Optoelectric Properties, and Photocatalytic Selectivity

Kun Liu,Lianjie Zhu,Youguang Sun,Dejun Wang,Hongbin Li,Tengfei Jiang

doi:10.1155/2012/849062

Kun Liu, Lianjie Zhu + Show 4 more

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https://doi.org/10.1155/2012/849062

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Abstract

Mesoporous anatase TiO2micro-nanometer composite structure was synthesized by solvothermal method at 180°C, followed by calcination at 400°C for 2 h. The as-prepared TiO2was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectrum (FT-IR). The specific surface area and pore size distribution were obtained from N2adsorption-desorption isotherm, and the optoelectric property of the mesoporous TiO2was studied by UV-Vis absorption spectrum and surface photovoltage spectra (SPS). The photocatalytic activity was evaluated by photodegradation of sole rhodamine B (RhB) and sole phenol aqueous solutions under simulated sunlight irradiation and compared with that of Degussa P-25 (P25) under the same conditions. The photodegradation preference of this mesoporous TiO2was also investigated for an RhB-phenol mixed solution. The results show that the TiO2composite structure consists of microspheres (∼0.5–2 μm in diameter) and irregular aggregates (several hundred nanometers) with rough surfaces and the average primary particle size is 10.2 nm. The photodegradation activities of this mesoporous TiO2on both RhB and phenol solutions are higher than those of P25. Moreover, this as-prepared TiO2exhibits photodegradation preference on RhB in the RhB-phenol mixture solution.

Highlights

In recent decades, TiO2 has received considerable attention due to its wide applications in fields such as solar cell, photocatalysis and lithium-ion batteries [1,2,3,4,5,6,7,8,9]
Since the presence of organic pollutant mixtures in real effluents from industries is frequent, we studied the preferential photodegradation of a rhodamine B (RhB)-phenol mixed solution over the as-prepared mesoporous TiO2 under simulated sunlight irradiation, as shown in Figure 8 where high-performance liquid chromatography (HPLC) was used to monitor the relative concentration of the two organics in their mixture solution at any reaction time and the maximum absorption wavelengths (552 nm for RhB and 270 nm for phenol) were chosen, respectively, for the measurement
Mesoporous anatase TiO2 micro-nanometer composite with high specific surface area was synthesized by a facile solvothermal method

Summary

Introduction

TiO2 has received considerable attention due to its wide applications in fields such as solar cell, photocatalysis and lithium-ion batteries [1,2,3,4,5,6,7,8,9]. In order to commercialize this technique, a few problems need to be solved at the first time: (1) preparation of catalyst with high specific surface area; (2) extending the light absorption capability of the catalyst to visible region; (3) easy separation of the catalyst from the suspension after photodegradation. In recent years, mesoporous TiO2 microspheres have received much attention because the porous structures would offer a high specific surface area, and the large particle size causes them to be separated and reclaimed since they can settle down in aqueous suspensions by gravity [13]. Increasing the particle size of a catalyst is often accompanied by a decrease in its photocatalytic activity, while a large-sized mesoporous micro-nanometer TiO2 composite structure with high specific surface area may solve this problem. We choose an RhB-phenol mixed aqueous solution as a model system to investigate the photodegradation preference of the TiO2 catalyst

Experimental

Results and Discussion

Conclusions