电力行业是全球能源组成的重要部分，电能的利用与转化是未来最有可能替代化石能源为人类生存与发展供能的方式。电化学反应可以直接有效地实现电能与化学能之间的转化，为了减少电化学反应能垒所造成的能量转换过程中的能量损失，电催化剂成为了一种重要的反应介质，其不参与电化学反应过程，也不影响反应产物，但可以有效降低电化学反应过程中的能垒，减少能量损耗。理想的电催化剂材料应该具有价廉高效、稳定性高等特点，金属有机框架材料（Metal-Organic Frameworks, MOFs）是一类由金属离子和有机配体通过配位作用组成的多孔性晶体材料，与传统金属/金属氧化物催化剂相比，其具有丰富且分散的金属位点和高比表面积，使其在电催化领域具有非常巨大的潜能。然而，MOFs 材料的本征低导电性和低原子利用率限制了其在电催化领域的广泛应用。为了获得理想的电催化材料，我们从非贵金属镍钴基低维 MOFs（Low-dimensional MOFs, LDMOFs）着手，对体相 MOFs 的三维结构进行优化设计与微观调整，有效地克服了MOFs 材料本征电导率低、原子利用率低等缺点，使其在电催化领域具有增强的优势，并且成功的进行了 LDMOFs 的功能复合与结构改性，获得了具有高催化活性与优越稳定性的系列 LDMOFs 基电催化材料，将其分别应用在了 OER 和 MOR 催化过程中，为新型高催化活性和长寿命电催化材料的设计与制备提供了新思路。具体内容及成果如下：
    （1）采用溶剂热法，通过调控反应条件，制备得到了具有超薄二维结构的 NiCo 基MOF 纳米片（NiCo BMOFNs），其具有 MOFs 高分散的金属位点、原子级厚度和高暴露的比表面积，具有良好的 OER 电催化活性，同时对 NiCo BMOFNs 进行了前驱体调节，实现了配体的部分替换，制备了一系列 NiCo-(BDC)x(BDC-NH2)1-x，并结合 DFT 理论计算，探究了 NiCo BMOFNs 上催化活性的来源，以及配体骨架上的接枝基团对 NiCo BMOFNs结构特性与催化性能的影响，为 2DMOFs 基材料的电催化应用与活性机理的理解提供了参考。
    （2）设计了一种原位半牺牲模板辅助策略，在层状双金属氢氧化物（NiCo-LDH）上原位生长超薄双金属 MOF 纳米片（BMOFNs），得到了具有 2D-2D 异质结构的复合电催化材料（NiCo-LDH@MOFs），其结合了 2DMOFs 在电催化领域中的高催化活性，同时利用了 LDH作为基底制备的异质结构通过化学键的作用保证了 2DMOFs在 LDH表面的均匀分散和牢固结合，所得的 NiCo-LDH@MOFs 具有高比表面积，增强的导电性，增大的电化学活性面积和优异的 OER 催化活性，并在稳定性上具有显著的提升，在超 300 h 的恒流测试下仅有 2.8%的性能损失，并进行了稳定性测试前后的表征，证明其具有优异的结构稳定性。此外引入了 AFM-IR 技术对 NiCo-LDH@MOFs 复合材料中的异质结构进行研究，并结合其他表征一同在纳米尺度上探究了 2D-2D 异质结构的生长过程，为 NiCo-LDH作为半牺牲模板原位生长 BMOFNs 提供了直接证据，引入了一种新的策略来描述两种不同的低维纳米材料之间的异质界面。这项工作实现一种高活性与稳定性的 2DMOFs 基复合电催化材料的原位生长策略，并提供了先进的组合表征技术来监测材料的生长过程，为纳米尺度上复合材料的形态结构的表征和生长机制的分析提供了参考。

    （3）设计了两步热诱导法，以 1DMOFs 纳米线（NiCo-MOFNWs）为前驱体，首先通过热诱导交联，诱导分离的 1DMOFs 纳米线的边缘弯曲交联形成特殊的自支撑网络结构，保证了 1DMOFs 的分散性、防止其团聚倾向，并且在热诱导纳米线交联的同时 NiCoMOFNWs的结晶度也得到了调控，造成了 NiCo-MOFNWs 由原本有序的晶体结构变成无序排列的非晶结构，引入了大量缺陷，随后通过热诱导磷化对上一步得到的 a-NiCoMOFNWs 进行原位 P 元素掺杂，优化金属位点对含氧物种的吸附能，得到了具有自支撑纳米线网络结构的 a-NiCo-MOFNWs-P，其在电催化 MOR 过程中具有优越的催化活性与稳定性（在进行了 1000 次 CV 循环后，仍保留 77%的催化性能），这项工作实现了一种高活性与稳定性的 1DMOFs 基电催化剂的构筑，为 1DMOFs 电催化材料结构设计与高效应用提供了参考。

The development of new sources of energy is crucial for the survival of human society.
Tremendous consumption of fossil fuel has promoted the development of industrial and social progress, but caused greatly problem to the environmental pollution meanwhile. The development of green and clean energy and related electrical industry is an important way to solve the problem of enegetic shortage and environmental pollution at present. Electrocatalytic reaction can directly and effectively realize the conversion of electric energy to chemical energy with cleam process without much byproducts, which can be a promising alternative way for energy conversion and storage to compete with fossil fuel. The exploration of new earth-abundant and highly efficient catalysts is of great importance for electrochemical energy storage and conversion. The sluggish kinetics of electrocatalytic reaction and the main requirements for using costly and rare noble metal-based catalysts (for example, Pt, RuO2 and IrO2) impede its practical application. Tremendous efforts have been devoted to improving the activity and reducing the costs of electrocatalysts. Metal-organic frame materials (MOFs) are a class of coordination compounds formed by metal ions and organic ligands. Compared with traditional metal/metal oxide catalysts, they have rich in scattered metal sites and specific surface area, which can ensure them with great potential in the field of electrocatalysis. Low-dimensional MOFs (LDMOFs) are the optimized design and micro adjustment of the bulk MOFs, which can effectively overcome the disadvantage of low intrinsic conductivity of MOFs in electrocatalytic process. Based on the above investigation, this paper focuses on the structural design and catalytic properties of LDMOFs-based materials for overcoming the indeficiency of intrinsic conductivity and metallic utilization and exploring the structure-activity relationship in electrocatalytic reactions. The specific contents and results are as follows:
(1) Firstly, a series of two-dimensional NiCo-based bimetal metal-organic frameworks (NiCo BMOFNs) was prepared through the solvothermal synthesis strategy. The products were characterized for morphological and structural analysis, which confirmed the ultrathin nanosheets nature and structural features of the as-prepared 2DMOFs. The partial replacement of the ligand in the as-prepared NiCo BMOFNs was conducted to fabricate the NiCo-(BDC)x(BDC-NH2)1-x, in which the optimized NiCo-(BDC)0.75(BDC-NH2)0.25 present the excellent catalytic performance in the electro-driven OER process. The theoretical calculation was conducted through the density functional theory (DFT) method to explore the source of the catalytic activity on the NiCo-(BDC)0.75(BDC-NH2)0.25 and investigate the influence of the grafting groups in the ligand on electrocatalytic activity, which provode a reference in understanding of the structure-activity relationships in 2DMOFs-based electrocatalysts.
(2) Based on the understanding of 2DMOFs, an excellent electrocatalyst NiCo-LDH@MOFs for OER with 2D-2D heterojunction and hierarchical architecture was fabricated through a semisacrificial template-assisted growth strategy. The NiCo-LDH serves as both the supporting substrates and semi-sacrificial precursors to promote the crystallization and vertical growth of NiCo BMOFNs decorated on the surface of LDHs. The confined metal source on the LDHs limits the spontaneous crystallization of Bimetal-MOFs (BMOFs) alone, and the chemical bonds of the metal-support interaction enhance the immobilization of the catalytic active components on the substrate. An Atomic force microscopy-infrared spectroscopy (AFM-IR) approach was introduced for the first time to monitor the growth process of the electrocatalyst at the nanoscale, providing direct evidence for the in-situ crystallization of MOF grains on the surface of the LDHs, which is
beneficial to reveal the relationship between the material structure and catalytic performance and provides a strategy for characterizing the heterogeneous interfaces between two different lowdimensional nanomaterials. Furthermore, the derived heterocomposite (denoted as NiCoLDH@MOF) with 2D-2D heterojunction and hierarchical architecture is endowed with highly accessible active sites, favourable electronic transmission capacity and excellent electrochemical corrosion resistance, which result in enhanced electrocatalytic performance in the oxygen evolution reaction: a low overpotential of 289 mV at 10 mA/cm2, a Tafel slope of 55.2 mV/dec, a 6-fold increase in the Electrochemical surface area (ECSA), and excellent long-term durability
(300 h, over 12 days) based on electrochemical measurements; thus, this material is superior to commercial RuO2 and most of previously reported electrocatalysts.
(3) Besides, we also investigated the rational design of 1DMOF-based electrocatalyst. A
novel architecture of phosphorus-doped direct interconnected networks of amorphous NiCo-MOF nanowires (a-NiCo-MOFNWs-P) derived from 1DMOF nanowires was fabricated by combining the strategies of heat-induced interconnection (HII) and heat-induced phosphorization (HIP). The as-prepared nanocatalyst exhibited direct interconnected network of 1DMOF nanowires with enlarged charge transport path, a-NiCo-MOFNWs with tailored crystallinity and P-doped aMOFNWs with optimized local electronic density of active metal sites for enhancing the intrinsic electrocatalytic performance. All the above features have met the criteria to be an excellent
material for electro-driven MOR. The rational design of the novel architecture of a-NiCoMOFNWs-P can provide a reference to the innovation of designing and fabricating the electrocatalysts.