Crystal growth and design of a facile synthesized uniform single crystalline football-like anatase TiO2 microspheres with exposed {0 0 1} facets
Section snippets
Introduction:
In recent years, intensive research attention has been paid to the design and synthesis of functional inorganic crystals with exposed high-energy surfaces, which normally show excellent physiochemical properties because of their unique geometrical and electronic structures such as high densities of atom steps, kinks, dangling bonds, and ledges [1], [2], [3]. It is well known that the performance of nanocrystal photocatalysts depends on their sizes, shape, composition, crystal phase and crystal
Preparation of anatase TiO2
The only used material was (NH4)2TiF6 (99.99%, AC). High-purity deionized water was used for the reaction solution preparation. The hydrothermal reaction was carried out at 120–180 °C for 1–24 h. In a typical experiment, 0.06 g of (NH4)2TiF6 (0.01 M) dissolved into 20 mL of deionized water were added into a 30 mL Teflon-lined stainless steel autoclave. The autoclave was kept at 150 °C for 16 h in an electric oven. After reaction, the products were separated by centrifugation, washed with deionized
Result and discussion
Fig. 1a shows the XRD pattern of the as-synthesized TiO2 microspheres. All the diffraction peaks can be indexed to the anatase crystal phase (Fig. 1a, bottom; space group I41/amd, JCPDS No. 21-1272), and no other phases can be detected. Moreover, the relative diffraction intensity of the (0 0 4) peak is much higher than that of bulk anatase, which indicates that more {0 0 1} facets have been exposed [6], [37]. Fig. 1b–c show SEM images of the anatase TiO2 particles. The prepared anatase TiO2
Conclusion
In summary, uniform anatase football-like TiO2 microspheres with exposed mirror-like plane (0 0 1) crystalline facets were successfully fabricated via an environment-friendly, facile and low-temperature hydrothermal method in water solution without any additional morphology controlling agents. The particles are comprised of square-shaped anatase TiO2 single crystals. It indicates that the formation of HF in the hydrolyze process of (NH4)2TiF6 and the surface-selective fluorinated on different
Acknowledgements
This study is supported by Chongqing Natural Science Foundation (cstc2013jcyjA20023) Foundation of Chongqing University of Arts and Sciences (Z2013CJ01, R2013CJ05 and R2012CJ13).
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