Dong Lihong, Chu Ying, Sun Wendong
Department of Chemistry, Northeast Normal University, Changchun, Jilin 130024, PR China.
Chemistry. 2008;14(16):5064-72. doi: 10.1002/chem.200701627.
Alpha-Ni(OH)(2) nanobelts, nanowires, short nanowires, and beta-Ni(OH)(2) nanoplates have been successfully prepared in high yields and purities by a convenient hydrothermal method under mild conditions from very simple systems composed only of NaOH, NiSO(4), and water. It has been found that the ratio of NaOH to NiSO(4) not only affects the morphology of the Ni(OH)(2) nanostructures, but also determines whether the product is of the alpha- or beta-crystal phase. A notable finding is that porous NiO nanobelts were produced after exposure of the Ni(OH)(2) products to an electron beam for several minutes during transmission electron microscopy (TEM) observations. Another unusual feature is that rectangular nanoplates with many gaps were obtained. Furthermore, porous NiO nanobelts, nanowires, and nanoplates could also be obtained by annealing the as-prepared Ni(OH)(2) products. A sequence of dissolution, recrystallization, and oriented attachment-assisted self-assembly of nanowires into nanobelts is proposed as a plausible mechanistic interpretation for the formation of the observed structures. The method presented here possesses several advantages, including high yields, high purities, low cost, and environmental benignity. It might feasibly be scaled-up for industrial mass production.
通过一种简便的水热法，在温和条件下，以仅由氢氧化钠、硫酸镍和水组成的非常简单的体系，已成功高产率、高纯度地制备出α - 氢氧化镍纳米带、纳米线、短纳米线以及β - 氢氧化镍纳米片。已发现氢氧化钠与硫酸镍的比例不仅影响氢氧化镍纳米结构的形态，还决定产物是α晶相还是β晶相。一个显著的发现是，在透射电子显微镜（TEM）观察期间，将氢氧化镍产物暴露于电子束几分钟后会生成多孔氧化镍纳米带。另一个不寻常的特征是获得了带有许多间隙的矩形纳米片。此外，通过对制备好的氢氧化镍产物进行退火处理，也可以得到多孔氧化镍纳米带、纳米线和纳米片。提出了一系列溶解、重结晶以及纳米线定向附着辅助自组装成纳米带的过程，作为对观察到的结构形成的一种合理机理解释。这里介绍的方法具有几个优点，包括高产率、高纯度、低成本以及环境友好性。它有可能可行地扩大规模用于工业大规模生产。
