基于电沉积法制备镍纳米网状结构薄膜材料的研究

发布时间：2018-05-16 15:30

本文选题：电沉积 + 镍　；参考：《上海交通大学》2010年硕士论文

【摘要】： 纳米材料由于其尺寸的原因具备许多大块固体所不具备的特性。近年来,在催化、活化、传感、表面增强散射等领域有着巨大的应用前景。其中,纳米网状薄膜材料由于其具有特殊的网状结构、极大的表面积,因此具有较高的电催化活性、憎水等特性,在催化和分离科学、憎水性涂料等领域上具有重要的应用,因而对该种材料的探索和研究极具意义。目前,纳米材料的制备方法有许多,其中,电化学方法仍处于起步阶段。因此,就一些新的简捷、有效制备方法的探索,对于开展相关的基础和应用研究仍具有重要的意义。在制备纳米材料的各种方法中,电沉积法具有如下优点: (1)可制备多种单金属或合金材料,应用范围广; (2)设备简单,成本低;(3)需克服的技术障碍少; (4)不受零件尺寸形状限制等。本文基于电沉积的方法,研究制备一种新型的镍纳米网状薄膜结构材料,设备方法简易,成本低廉,有望得到广泛的应用。通过对电沉积制备工艺的探索、纳米网状结构晶体生长机理的研究及镍纳米网状结构薄膜材料表面润湿行为的研究,可以获得如下结论: 1、通过调整电沉积镀液的成分(主盐和添加剂)、沉积工艺参数,能够稳定地获得镍纳米网状结构薄膜材料:添加剂乙胺盐酸盐的加入,可以使得表面微观结构从平整的镍层变为纳米网状结构;该种结构在氯化镍作为主盐的溶液中能够获得,而在氨基磺酸镍作为主盐的镀液中电沉积只能得到圆胞状突起结构;对各种电沉积条件的研究表明,小范围内的温度变化对纳米网结构的尺寸影响不大,在40~50℃间是形成纳米网结构的适宜温度区间;在较高的电流密度下(5 A/dm2)才能得到均匀分布的纳米网结构;随着沉积时间的延长,表面结构并没有太大变化。 2、断面结构观察证实,该种镍纳米网状结构薄膜层中存在一定孔隙,具有一定的空间架构结构,通过XRD能谱分析及晶粒尺寸计算,发现在不同沉积时间下得到的晶粒尺寸基本一致,对比SEM照片中读图计算转换得到的半径值同XRD拟合得到的半径值,发现两者数值较为接近。因此推断每一个枝状结构代表一个晶粒,而该薄膜为多晶沉积层。 3、采用脉冲电镀的方式能得到较直流体系下结构更为粗大稳定的微纳米网结构。并且在脉冲电流方式下,选用较小的脉冲电流密度就能获得均匀的微纳米结构,提高了电流效率;脉冲频率对沉积层形貌的影响不是很大,在频率分别为1,10和100的条件下,得到相近的表面形貌;脉冲占空比的改变对沉积层形貌由显著影响,随着占空比的减小,SEM观察到的枝状结构不断增大,并且XRD计算得到的晶粒尺寸也不断增大。 4、表面润湿性能测试结果表明具有枝状纳米网结构的表面较平滑的镍沉积层表面以及胞状突起状表面润湿角有较大的提高,其数值可达到130~140°,个别已接近超疏水性。对于同样具有枝状纳米网结构的表面,随着枝状结构的粗大,润湿角数值呈现上升趋势;分析脉冲导通时间及晶粒尺寸同润湿角之间的关系,我们可以发现,随着脉冲导通时间的延长,晶粒尺寸不断增大,相应的润湿角也呈现一个增大的过程。
[Abstract]:Nanomaterials have many potential applications in the fields of catalysis, activation, sensing, and surface enhanced scattering because of their size. In recent years, nanoscale thin film materials have high electrocatalytic activity because of their special network structure and large surface area. Water and other properties have important applications in the fields of catalysis and separation science, hydrophobic coatings and so on. Therefore, the exploration and research of this material is of great significance.
At present, there are many preparation methods of nanomaterials, among them, electrochemical methods are still in the initial stage. Therefore, the exploration of some new simple and effective preparation methods is still of great significance for the development of relevant basic and applied research. In the various methods of preparing nanomaterials, electrodeposition has the following advantages: (1) more preparation can be made. A single metal or alloy material is widely used. (2) the equipment is simple and the cost is low; (3) the technical barriers to overcome are few; (4) it is not restricted by the size and shape of parts.
Based on the electrodeposition method, a new type of nickel nano mesh thin film structure material is prepared. The equipment is simple and low cost. It is expected to be widely used. Through the exploration of the preparation process of electrodeposition, the study of the crystal growth mechanism of the nanoscale network structure and the research of the wetting behavior of the surface of the Ni nanoscale reticulated structure film material The following conclusions can be obtained:
1, by adjusting the composition of the electrodeposition plating bath (main salt and additive) and the deposition process parameters, the nickel nano mesh structure film material can be obtained stably. The addition of the additive ethylamine hydrochloride can make the surface microstructure change from the flat nickel layer to the nanoscale network structure, which can be obtained in the solution of the nickel chloride as the main salt solution. The electrodeposition of nickel ammonium sulfonate as the main salt bath can only obtain a cycic protuberance structure. The study of various electrodeposition conditions shows that the temperature change within a small range has little effect on the size of nanoscale structure, and is a suitable temperature range for the formation of nanoscale structure at 40~50 C; at a high current density (5 A/dm2) The uniform distribution of nanostructures can be obtained. With the prolongation of deposition time, the surface structure does not change much.
2, the observation of the section structure confirms that there is a certain pore in the Ni nanoscale mesh layer, and has a certain spatial structure. Through the XRD spectrum analysis and the grain size calculation, it is found that the grain size obtained at different deposition time is basically the same. The radius values obtained by comparing the calculation of the calculation of the reading map in the SEM photograph are fitted to the XRD. The value of the radius is closer to each other, so it is deduced that each dendrite structure represents a grain, which is a polycrystalline deposit.
3, the micro nanoscale structure with more coarse and stable structure in the DC system can be obtained by pulse electroplating. Under the pulse current mode, a uniform micro nano structure can be obtained by using the smaller pulse current density, and the current efficiency is improved. The influence of the pulse frequency on the morphology of the deposition layer is not very large, and the frequency is 1,10, respectively. Under the condition of 100 and 100, the similar surface morphology is obtained, and the change of the pulse duty ratio has a significant influence on the morphology of the deposition layer. With the decrease of the duty ratio, the dendritic structure observed by SEM increases continuously, and the grain size obtained by the XRD calculation is also increasing.
4, the surface wettability test results show that the surface of the smooth nickel deposition layer and the surface wetting angle of the cell like surface have a great improvement, and the numerical value can reach 130~140 degrees, which is close to the superhydrophobicity. For the surface of the branch like structure, the surface of the branch like structure is wetted. With the analysis of the relationship between the time of pulse conduction and the wetting angle of the grain size, we can find that the grain size increases with the prolongation of the pulse conduction time, and the corresponding wetting angle also presents an increase process.

【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：TB383.2

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