Nucleation−Dissolution−Recrystallization: A New Growth Mechanism for t-Selenium Nanotubes
Nucleation−Dissolution−Recrystallization: A New Growth Mechanism for t-Selenium Nanotubes
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DOI：
10.1021/cg050444c
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发表时间：
2006-01
影响因子：
3.8
通讯作者：
Guangcheng Xi;Kan Xiong;Qingbiao Zhao;Rui Zhang;Houbo Zhang;Y. Qian
中科院分区：
文献类型：
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作者：
Guangcheng Xi;Kan Xiong;Qingbiao Zhao;Rui Zhang;Houbo Zhang;Y. Qian
我们报告了一个水热反应，使t-硒纳米管，在没有表面活性剂或聚合物的情况下，直接纳米粒子的生长，并没有外部添加的力量（如超声波）。一系列的电子显微镜表征结果表明，硒纳米管的生长是由成核溶解再结晶生长机制。在这一机制中，硒纳米粒子首先在水热体系中形成，然后开始溶解并生长在大的硒纳米粒子上，得到球形微粒。然后，球形微粒逐渐溶解，在溶液中产生硒原子;这些硒原子重新转移到球形微粒的表面上并重结晶。沿着溶解-再结晶过程，球形微粒逐渐演化为新型的沟槽状纳米结构。纳米凹槽可以沿圆周方向和管轴方向沿着生长，直到所有的球形微粒被完全消耗，最终生长成硒纳米管。研究发现，这种生长机制受到温度和NaOH浓度的强烈影响。通过调节温度和NaOH浓度，可以分别合成出硒纳米管、纳米线、微米棒、多孔微管和多面体。
We report a hydrothermal reaction to make t-selenium nanotubes, in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally added forces (such as ultrasonic). A series of electron microscopy characterization results suggest that the growth of t-selenium nanotubes is governed by a nucleation-dissolution-recrystallization growth mechanism. In this mechanism, t-selenium nanoparticles were initially formed in the hydrothermal system, then the t-selenium nanoparticles started to dissolve into the solution and grow onto large nanoparticles of selenium, and spherelike microparticles were obtained. The spherelike microparticles then gradually dissolved to generate selenium atoms in the solution; these selenium atoms were renewedly transferred onto the surfaces of the spherelike microparticles and were recrystallized. Along with the dissolution-recrystallization process, the spherelike microparticles gradually evolved into novel groovelike nanostructures. The nanogrooves could grow along the circumferential direction and the tuber axis direction until all spherelike microparticles had been completely consumed, eventually growing into t-selenium nanotubes. Studies found that this growth mechanism is strongly affected by temperature and concentrations of NaOH. By adjusting temperature and concentrations of NaOH, t-selenium nanotubes, nanowires, microrods, porous microtubes, and polyhedrons can be synthesized, respectively.