Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (04): 858-866.doi: 10.3866/PKU.WHXB201302041

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Growth Mechanism and Characterization of Flexible TiO2 Nanowhisker Films Hydrothermally Synthesized in Dilute Alkaline Solution

DENG Jie, TAO Jie, WU Tao, TAO Hai-Jun   

  1. College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
  • Received:2012-09-03 Revised:2013-01-30 Published:2013-03-25
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51202112), Jiangsu Key Technology R&D Program, China (BE2009130), and Research Funding of Nanjing University of Aeronautics and Astronautics, China (NS2010153).

Abstract:

Flexible oriented TiO2 nanowhisker films with large aspect ratios were hydrothermally prepared in 1 mol·L-1 NaOH solution from Ti film deposited by magnetron sputtering on a flexible stainless steel substrate. The influence of the Ti film deposition conditions on the resulting TiO2 nanowhisker films was investigated. We also systematically studied the effects of the hydrothermal parameters on the nanowhisker films and their growth mechanism. The samples were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and high resolution transmission electron microscopy (HRTEM). The results showed that nanowhisker film prepared from Ti film deposited at 600 ° C had stronger adhesion to the substrate compared with that prepared from Ti film deposited at room temperature. The as-prepared TiO2 nanowhiskers were single crystalline anatase and were the result of transformation of Ti into Na2Ti2O4(OH)2 and H2Ti2O5·H2O. The nanowhiskers took shape during the hydrothermal synthesis, preferably oriented parallel to (100) crystal face of Na2Ti2O4(OH)2, and experienced splitting conversion from nanobelts to nanowire harnesses and nanowires. The formation of vertical nanowhisker films was ascribed to a cooperative effect of the dilute NaOH solution and the higher hydrothermal temperature (220 ° C). The photoelectrochemical properties of the films were investigated in Na2SO4 solution, and the results showed that the as-prepared TiO2 nanowhisker film exhibited better photoelectrochemical properties than those of zero-dimensional nanoparticle films and two-dimensional nanobelt films, indicating a good potential for practical application.

Key words: TiO2, Nanowhisker, Thin film, Hydrothermal synthesis, Flexible stainless steel substrate, Photoelectrical property

MSC2000: 

  • O643