Ni(OH)2及Co(OH)2片状纳米晶体的合成与表征

摘要

使用强碱氢氧化钾为沉淀剂,通过水热法成功合成了具有六角形貌的过渡金属氢氧化物Ni(OH)2及Co(OH)2片状纳米晶.利用X射线粉末衍射仪和透射电子显微镜对样品的结构和形貌进行了表征.透射电镜观察结果显示:Ni(OH)2相为规则六角纳米片,Co(OH)2相为纳米片和纳米棒的混合物.选区衍射结果指出:Ni(OH)2及Co(OH)2纳米晶体均为单晶体.Ni(OH)2及Co(OH)2纳米片的产率分别达到了70%和90%.将实验结果同前人的过渡族金属氢氧化物纳米片报道进行了比较,提出了一个新的片状纳米晶的形成机制,指出在正常的沉淀条件下,Ni(OH)2及Co(OH)2纳米晶的稳定形貌总为六角片状.%Transition metal hydroxides Ni (OH)2 and Co (OH)2 nano-sheet crystals with hexagonal morphology have been successfully synthesized through hydrothermal method using strong alkali (KOH) as precipitator. The structure and morphology of the as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM observations exhibit that the Co(OH)2 phase is formed with the regular hexangular nano-sheets, while Ni( OH)2 phase a mixture of nano-sheets and nano-rods. Selected area electron diffraction (SAED) patterns reveal the single crystalline nature of the entire nano-sheet. The yields of the nano-sheets for Ni(OH)2 and Co(OH)2 reach about 70% and 90%, respectively. It is proposed that hexagonal sheet is a stable crystalline morphology for the current solid compounds under normal precipitation conditions.Comparing with the previous reports on synthesis of transition metal hydroxide nano-sheet by the other methods, a new formation mechanism of nano-sheets has been discussed.