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设计实验研究了以无机镍盐和NaOH为原料,利用水热法制备Ni（OH）2纳米线,OH-和SO24-对于产物形貌的影响,并利用X射线衍射（XRD）,傅立叶变换红外光谱（FTIR）,透射电镜（TEM）等对材料结构、形貌和成分进行了表征,研究了Ni（OH）2纳米线形成的相关机理.结果表明,低的OH-浓度与高纯的SO24-水热环境是α-Ni（OH）2纳米线形成的关键因素.SO24-能够加速α-Ni（OH）2晶体沿[001]方向的生长,而OH-含量较低时,较低的库伦斥力不足以阻碍晶体沿[001]方向生长过程的进行.“,”O 42-ions and OH-ions play important roles in hydrothermal synthesis of Ni（OH）2 nanostructures with only inorganic nickel salt and NaOH.The whole process could be divided into 2 parts,the preparation of Ni（OH）2 gel and its hydrothermal reaction.According to our analysis,the former one is an ionic-reaction which produces amorphous Ni（OH）2.It is the later one when Ni（OH）2gel crystallizes that dominates the polymorph and morphology of final products.The influence of OH-on morphologies of Ni（OH）2 has been studied by changing the ratio of n（SO 42-）/n（OH-）.To discuss the effect of SO 42-ions in hydrothermal system on crystal growth,we wash the gel which is prepared by NiCl 2and NaOH with the mixture solution of Na2SO4 and NiSO4 for different times,so that Cl-ions in the gel solution could be replaced by SO 42-ions in varying degrees.Then the nanosized Ni（OH）2 products is prepared by hydrothermal treatment.Also,the samples were characterized by means of X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR） and transmission electron microscopy（TEM）.TEM results show that there will be 2 main nanostructures in different hydrothermal conditions： nanowires and nanosheets.XRD and FTIR results reveals that the nanowires is Ni（SO4）0.3（OH）1.4,one kind of α-Ni（OH）2,and the nanosheet is β-Ni（OH）2.We finally got a conclusion that low amount of OH-and pure SO 42-environment is advantageous to synthesis of α-Ni（OH）2 nanowires.Since α-Ni（OH）2 is hydroxyl-deficient and consists of stacked Ni（OH）2-x layers toward which the SO 42-ion has a higher affinity than other ions such as Cl-and NO-3,the SO 42-ion is able to enter its interlayers.The structure is stabilized due to the strong coordination bonds between SO 42-and Ni2＋ in Ni（OH）2-x layers.Also,free Ni2＋ ions in solution would be linked to intercalated SO 42-through coordination bonds,so that new Ni（OH）2-x layers could form constantly and stack along the c-axis.As a result,there will be a preferential growth in the [001] direction.However,this process is not likely to continue when there is high amount of OH-,which may cause high Coulomb repulsion along the [001] direction.