铂基有序微纳阵列的构筑及其甲醇催化性能研究

发布时间：2018-03-23 19:21

本文选题：胶体晶体模板　切入点：电化学沉积　出处：《西南大学》2017年硕士论文

【摘要】：纳米技术的飞跃发展已经从本质上改变了科学家们合成器件的方法,以及改变了器件本身的性质。因此,随着纳米技术的成熟稳定,它已成为科研领域中十分热门的领域,尤其是对于多维度、形貌各异、性能优越的纳米材料的合成。当前,由于二维有序微纳阵列结构器件在许多领域均表现出良好的性能(如生物技术、传感器、燃料电池、光电子学、磁学等领域),所以科研工作者们迫切的希望能利用纳米技术,制备出更多、更新颖的二维有序微纳阵列。本论文中,我们将聚苯乙烯小球,在液面进行自组装后,合成了大面积的聚苯乙烯单层膜;利用恒电流、两步电流沉积法在ITO电极或Au电极上,沉积出Pt基碗状微纳阵列结构。表征了其形貌,测试了其在直接甲醇燃料电池(DMFC)中的催化能力,探索出影响甲醇燃料电池的原因。其主要内容如下:(1)采用液面自组装的方法,在清洗干净的载玻片上,合成了大面积的聚苯乙烯胶体晶体膜,并利用扫描电子显微镜(SEM)对其形貌进行表征。(2)以高度有序的聚苯乙烯小球为模板,首先研究了基底电极对纳米器件的形貌、性能的影响。作为对比,将聚苯乙烯胶体球分别铺设在ITO电极、镀金玻璃电极上;采用恒电流沉积法,同一沉积参数下,在两种基底电极上构筑了Pt-Ni微纳阵列;通过SEM、XRD分析其形貌成分以及结构;紧接着进行了甲醇催化性能的测试,发现Au电极上生成的微纳阵列,具有着更强的甲醇催化性能,其最高峰电流值约为12mA(为在ITO电极上测得其甲醇催化性能的2倍)(3)在Au电极上沉积出Pt-Co微纳阵列材料。将胶体球模板转移至Au电极上干燥后,置于四种不同浓度配比的硫酸钴和氯铂酸的混合溶液中;其中氯铂酸浓度不改变,只改变硫酸钴浓度。在四种钴含量的混合溶液中,采用恒电流沉积法,同一沉积参数下,制备出了4种Pt-Co微纳阵列;对该材料,进行甲醇催化性能研究时,发现当Co含量为0.06M时,其甲醇催化的峰电流值最大,约为19mA。得出当电解液浓度的改变时,电沉积后所生成的材料,其形貌与性能将会受到显著的影响。(4)在覆盖有二维胶体晶体球模板的Au电极上,利用两步电流法,分别沉积出了Pt-Fe和Pt-Ni的微纳阵列结构,并研究两种电极材料对甲醇的电催化氧化性能。两步电沉积后,利用扫描电子显微镜对这两种器件形貌进行观察,发现该方法制备的阵列形貌与恒电流法制备的材料明显不同,而是在第一层(Pt)的基础上,继续生长出了第二种(Fe/Ni)目标物质。通过CHI660电化学工作站对其进行甲醇催化性能测试,分析实验数据后,发现利用两步电流法得到的分层纳米材料,也能成为新型的催化剂。制备实验过程简单、容易重复、经济又环保。
[Abstract]:The rapid development of nanotechnology has fundamentally changed the way scientists synthesize devices and the properties of devices themselves. Therefore, with the maturity and stability of nanotechnology, it has become a very hot field in the field of scientific research. Especially for the synthesis of nanomaterials with multiple dimensions, different morphologies and superior performance. At present, due to the excellent performance of two-dimensional ordered micro / nano array devices in many fields (such as biotechnology, sensors, fuel cells, etc.), In the fields of optoelectronics, magnetism and so on, researchers are eager to make use of nanotechnology to produce more, more novel two-dimensional ordered microarrays. In this paper, we will self-assemble polystyrene pellets on liquid surface. A large area of polystyrene monolayer film was synthesized, and the structure of Pt-base bowl microarray was deposited on ITO electrode or au electrode by the method of constant current and two-step current deposition, and its morphology was characterized. The catalytic ability of DMFCin DMFCwas tested, and the reasons influencing the DMFCwere explored. The main contents are as follows: (1) the liquid level self-assembly method was used to clean the clean slide. A large area of polystyrene colloidal crystal film was synthesized and characterized by scanning electron microscopy (SEM). As a contrast, polystyrene colloidal spheres were laid on ITO electrode and gold-plated glass electrode respectively, and Pt-Ni microarrays were constructed on two kinds of substrate electrodes by constant current deposition method and the same deposition parameters. The morphology and structure of the electrode were analyzed by SEM XRD, and then the catalytic performance of methanol was tested. It was found that the micro-nano array formed on the au electrode had stronger methanol catalytic performance. Its peak current value is about 12mA3 times the catalytic activity of methanol on the ITO electrode. The Pt-Co microarray materials are deposited on the au electrode. The colloidal sphere template is transferred to the au electrode for drying. In the mixed solution of four different concentrations of cobalt sulfate and chloroplatinic acid, in which the concentration of chloroplatinic acid does not change, only the concentration of cobalt sulfate is changed. In the mixed solution of four kinds of cobalt content, the method of constant current deposition is used under the same deposition parameters, Four kinds of Pt-Co microarrays were prepared, and when the catalytic performance of methanol was studied, it was found that when Co content was 0.06 M, the peak current of methanol catalytic activity was about 19mA.The results showed that the peak current value of methanol catalyst was about 19mAwhen the concentration of electrolyte was changed. The morphology and properties of the electrodeposited materials will be significantly affected. (4) on the au electrode covered with two-dimensional colloidal crystal sphere template, the microarray structures of Pt-Fe and Pt-Ni have been deposited by two-step current method, respectively. The electrocatalytic oxidation of methanol by two kinds of electrode materials was studied. After two-step electrodeposition, the morphology of the two kinds of devices was observed by scanning electron microscope (SEM). It was found that the array morphology prepared by this method was obviously different from that prepared by constant-current method. On the basis of the first layer (Pt), the second Fe / Ni target material was grown. The methanol catalytic performance was tested by CHI660 electrochemical workstation. After analyzing the experimental data, it was found that the layered nanomaterials were obtained by two-step current method. It can also be used as a new catalyst. The preparation process is simple, easy to repeat, economical and environmentally friendly.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TB383.1

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