Low-Dimensional Nanomaterials: Controlled Growth, Characterization And Property Study

Low-dimensional nanomaterials have been attracting considerable attention due to their interesting properties dependent on size and shape, and the nanotechnology is also highly desirable in 21th century. Beceause of the composition, dimension and the shape of the nanomaterials play a crucial role in their properties and applications, it is necessary to synthesize morphology- and composition-controlled low-dimensional nanomaterials. In this dissertation, we synthesized some low-dimensional nanostructures by some simple controllable methods. The growth mechanisms have also been discussed.1.We have systematically investigated the preparing process of aluminum borate nanowhiskers. According to the synthesis process, we pay much attention to the key effects: the preparation of precursors from sol-gel method, the ratio of Al/B in the precursors, the calcined temperature. Under the optional conditions, The fine Al₄B₂O₉ nanowhiskers with the average diameter of-50 nm and the length of-1um were obtained by the calcination of Al/B-2 xerogel at 1000℃, while the heat treatment at 1100℃for Al/B-1 xerogel gave rise to the Al₁₈B₄O₃₃ nanowhiskers with the average diameter of-50 nm and the length of -1μm. A possible growth mechanism was also proposed.2. A sophisticated production of 3Dγ-AlOOH (boehmite) hierarchical nanoarchitectures built up of nanostrips has been successfully synthesized. The template/substrate-free and surfactant-free synthetic methodology of hierarchical structures of 1D nanostructures reported in this chapter is a simple, inexpensive, scalable, and mild synthetic process. We have also discussed the thermal stability of the Al₄B₂O₉ nanorods under hydrothermal condition. After that, we obtain the conclusion that the addition of the Al₄B₂O₉ nanorods played a key role in the synthesis of such nanoarchitectures, such as increasing the chemical potential of the solution, control the saturation of the solution to separate the nucleation and growth and supply the Al source continuously. Such a facile method and the idea of control nucleation and growth are applicable to synthesize other metal hydroxide hierarchical nanoarchitectures.3. Controlled growth of the nanomaterials was carried out. We catch our clues from the pre-work of our group and my grope about the thermal stability of the Al₄B₂O₉ nanorods under hydrothermal condition, a facile method was firstly proposed to synthesize AlOOH nanomaterials with large yield. According to control the reaction conditions (solution, PH value and surfactant), A100H nanomaterials with various shapes were synthesized. Such a facile, inexpensive, scalable, and mild method was applicable to synthesize other metal hydroxide hierarchical nanoarchitectures.