高效二维三元TMC自支撑催化电极材料的精确合成与控制

2D ternary transition metal chalcogenides (TMC) plays an important role in Pt-free catalysts due to its widely tunable properties. However, the traditional wet-chemical method for the precise control of the atomic ratio of 2D ternary TMC materials is relatively few, so that scholars lack of accurate understanding of the 2D ternary TMC nucleation and growth process in solvent environment. Consequently, the catalytic mechanism of 2D-ternary-TMC-based self-supporting electrodes is difficult to study in depth. This project intends to control the atomic ratio of 2D ternary TMC material accurately by means of multi-step reaction or rate-limiting reaction. Then, it was edge orientated grown on the surface of the chemically modified conductive substrate in-situ. The effects of substrate surface chemistry on the nucleation and growth of two-dimensional ternary TMC on the substrate surface were then studied. Last, the interlayer spacing of the edge-terminated 2D TMC was manipulated through chemical or electrochemical methods. Finally, the relationships between electrochemical catalytic performance and atomic ratio, in-situ growth orientation, interlayer space were revealed. This project intends to give a strong in-depth support to develop self-supported electrode materials with high stability and efficiency.

二维三元过渡金属硫族化合物（TMC）因其广泛的性质调节空间，在提升非铂催化材料的电催化性能方面有着重要的意义。传统湿化学法对二维三元TMC原子比例的精确调控研究相对较难，导致学者们对溶剂环境下二维三元TMC成核及生长过程缺乏深入认识，使基于二维三元TMC的自支撑电极的制备过程难以精确控制。本项目拟以湿化学合成法为基础，通过多步反应或限速反应等手段，对二维三元TMC的原子比例进行精确调控，并将其在化学改性的导电基底表面进行原位边缘取向生长，研究基底表面化学性质对二维三元TMC在基底表面成核及生长过程的影响，最后利用化学或电化学手段，对在基底表面边缘取向生长的二维三元TMC的层间距进行调控。揭示原子比例、基底原位生长取向、层间距与电催化性能之间的构效关系，努力为获得具有高催化活性和高稳定性的自支撑催化电极材料提供坚实的理论依据。

设计与开发具有高电催化活性的催化材料对未来的能源领域有着重大意义。本研究立足于探索金属原子掺杂的二维材料以及双金属复合型材料的自身结构、形貌、尺寸等结构性质与电催化活性及稳定性之间的构效关系，并以此为基础，初步探索了复合型电催化材料之间的界面电荷调控作用对电催化过程的影响。本部分的研究结果表明，无论是金属化合物-金属化合物之间的复合还是金属-金属化合物之间的复合，都可以有效调控主催化剂的表面电荷，从而优化其表面能，提高电催化的活性，并在此基础上提出了界面极化提高极性分子解离效率的思路。而金属原子掺杂的二维材料则对被掺杂材料自身的物理化学性质进行了调控，不仅提高了催化活性位点的活性，同时提高了材料自身的导电性和稳定性。研究结果表明，不同的金属原子的掺杂对被掺杂材料的改变不尽相同，Ta对NiFe LDH的掺杂可增加新的活性位点，Mo对CoSe的掺杂改变了CoSe的晶胞尺寸，而V对NiCo2O4的掺杂则调节了NiCo2O4的氧空位数量。这些结果对于未来设计和制备高性能的电催化材料提供了一些思路。以此为基础，在今后的工作中进一步系统性研究界面极化作用对电催化活性优化的基本规律，深入探索界面电荷作用与电催化活性之间的物理量表达。