乐高积木法制备二维纳米多孔金-钯复合材料及其性能研究

Architecting nanomaterials into hierarchic and organized structures is a rational way to fabricate advanced functional materials, like playing Lego. In this project, firstly, it is proposed that gold nanocrystals of different shapes and sizes were used as primary building blocks to fabricate monolayer ultrathin films of gold nanocrystals via their interfacial assembly, and further to fabricate monolayer nanoporous gold ultrathin films (NPGUTFs) with different ligament sizes and different surface structures on the ligaments (as secondary building blocks) via overgrowth at air/liquid interfaces. Secondly, as-prepared NPGUTFs were used as templates to fabricate monolayer nanoporous gold-palladium (Au-Pd) ultrathin films (NPG-Pd UTFs) with different ligament sizes and different surface structures on the ligaments (as secondary building blocks). The electrocatalytic performances of as-prepared NPG-Pd UTFs were investigated to explore how their nanostructures affect them. Thirdly, these as-prepared secondary building blocks were used as modules to construct two-dimensional (2D), nanoporous Au-Pd electrocatalysts with control. Similarly, the electrocatalytic performances of 2D nanoporous Au-Pd composite materials were investigated to explore how their size (thickness and numbers of layers), interaction and synergistic effect of supporters, promoters (Au) and active constituent (Pd), and effect of composite constructions of monolayer ultrathin films of different types affect them. Lastly, controlled fabrication of 2D nanoporous Au-Pd composite materials with higher electrocatalytic activity and higher stability can be successively completed and their electrocatalytic performance can be adjusted by the structure design, thus achieving the purpose of their applications in the electrocatalysis and energy system.

一种制备先进功能材料的合理方法就是把已有的纳米材料组合成分级、有序的结构，就像玩乐高积木一样。本项目提出以不同形貌和尺寸的金纳米晶为初级构筑单元，首先通过它们的界面组装制备单层金纳米晶超薄膜，然后再通过在气液界面的过度生长来制备具有不同的纽带直径和纽带表面结构的单层纳米多孔金超薄膜(二级构筑单元)；接着以此超薄膜为模板，制备具有不同纽带直径和不同表面结构的单层纳米多孔金-钯超薄膜(二级构筑单元)，并研究其纳米结构与其电催化性能的关系；然后以这些二级构筑单元为模块进行可控搭建制备二维纳米多孔金-钯复合材料，并研究其尺寸(厚度和层数)、载体、促进剂(金)和活性组分之间(钯)的相互作用和协同效应以及单层膜的组合结构效应等对其电催化性能的影响；最后实现具有高稳定性和高电催化活性的二维纳米多孔金-钯复合材料的可控制备和通过结构设计能调控其电催化性能，从而实现它们在电催化和能源等领域应用的目的。

为了满足未来的能源需求，绿色和可持续能源（燃料电池，超级电容器等）的研究和应用从而被广泛关注。然而，电极材料是其主要部件，因此在很大程度上依赖于高效和稳定的电催化剂的制备。在本项目中，以不同形貌和尺寸的金纳米晶为初级构筑单元，制备了一系列金基贵金属电催化剂，研究了其尺寸，纳米结构，组成与其电催化性能的关系。最后实现具有高稳定性和高电催化活性的金-钯复合材料的可控制备和通过结构设计能调控其电催化性能，从而实现它们在电催化和能源等领域应用的目的。主要研究内容和重要结果如下：..(1) 通过在在CTAB/CTAC体系中可控合成一系列不同形状，尺寸和组成的金-钯纳米晶（如，高晶面的{331}的三八二十四面体(TOH)的金纳米晶，不规则凹形长方体金@钯纳米颗粒，钯层状外延生长的三八二十四面体金@钯纳米颗粒，超支化的，具有三八二十四面体形貌的核壳结构金@钯铂纳米颗粒，核壳结构的六八四十八面体(HOH)金@金钯纳米颗粒，），实现了它们在电催化方面的应用。(Nanoscale, 2015, 7, 8405 & 2015, 7, 20105 & 2018, 10, 22302; J. Mater. Chem. A, 2017, 5, 18878 & 2018, 6, 7675)..(2) 通过在柠檬酸钠体系中可控合成一系列不同形状，尺寸和组成的金-钯纳米晶(具有开口的、蛋黄蛋壳结构的金钯纳米晶，具有高催化活性的最小尺寸的核壳金@铂纳米枝状物，壳层表面组成不同的金@银钯纳米晶，含有不同密度缺陷的金钯纳米晶，金钯合金纳米线网络结构和含不同表面晶面的金钯气凝胶), 实现了它们在电催化方面的应用 (Chem. Sci., 2015, 6, 4350-4357; J. Mater. Chem. A, 2015, 3, 368; J. Phys. Chem. C, 2015, 119, 18434; J. Mater. Chem. A, 2017, 5, 6992； ACS Appl. Mater. Interfaces, 2018, 10,602 & 2018, 10, 23081)。. (3) 其他发表的和未发表的工作见报告正文。