单层纳米片三维结构的控制合成及其电催化性能研究

Three dimensional structure composed of single layer nanosheets have drawn intense interest recently for their promising applications in electrocatalysis and energy storage, due to the unique properties of the single layer nanosheets originated from the quantum confined effect, surface effect and anisotropism, as well as the high structure stability and abundant active sites of the three dimensional structure.However, it remains a great challenge to synthesize the high quality three dimensional structures composed of single layer nanosheets in a facile solution chemistry. Here, we propose to prepare the three dimensional structures through a facile solution chemistry by adding two different functional ligands, in which one ligand directs the nucleation of the nanosheets in three dimension and another ligand leads the growth of the nanosheets in two dimension, resulting the three dimensional structures composed of nanosheets. The reaction conditions, including the reaction temperature, reaction time, the ligands compostion and the precursors concentraions, will be systematically investigated to obtain the three dimensional structures with high monodispersity, tunable pore size, and high structural stability, and further study theie applications in electrocatalysis.

单层纳米片三维结构由单层纳米片组装而成，其中单层纳米片由于其量子限域效应、表面效应以及高度各向异性体现出与体相材料截然不同的物理化学性质，同时三维结构由于其结构稳定并且使纳米片活性位点充分暴露（片与片之间不相互堆叠），因此，在电催化、能量存储等领域具有诱人的应用前景。但是如何建立简单、普适的溶液合成策略，制备高质量单层纳米片三维结构并开展其性能研究是目前无机化学制备与合成技术亟待解决的问题。本课题选择金属硫属化合物作为单层纳米片基元来构建其三维结构，拟采用液相回流法，通过选择两种功能配体分子，其中一种配体分子指导纳米晶体在三维空间的成核和生长，另一种引导纳米片在二维方向生长，协同作用制备单层纳米片三维结构，优化反应条件（温度、时间、配体分子比例、前驱体浓度等），获得尺寸均匀、孔隙率可调、稳定性高的高质量单层纳米片三维结构，并开展其在电催化领域的应用基础研究。

能源危机日益加剧，发展储量丰富且价格低廉以及性能优越的过渡金属化合物的电催化剂具有重大的实际意义。本项目主要聚焦于三维层状多表面活性位点催化剂的合成和电催化性能研究，具体为：1）海胆状多孔磷化钴（CoP）纳米晶析氢催化剂，有序的三维机构使得每个活性位点能够保持完好，确保了催化剂析氢反应的高活性和高稳定性；2）多孔的尖晶石型钴锰氧化合物(CoxMn3-xO4)，通过调节反应参数获得尺寸、组成及结构可控的材料，具有高效的氧还原（ORR）催化性能和优越的稳定性；3）原子级Pt团簇修饰的多孔α相氢氧化镍纳米线，极大地提高Pt的原子利用率，并且 Ni(OH)2可以促进水的解离，从更易与Pt结合形成吸附H, 使其具有更好的析氢效果；4）氮掺杂碳包覆不同晶相镍的核壳结构（Ni@NC），验证了亚稳相态六方相Ni@NC的电催化性能比稳定相态立方相的Ni@NC更好，活性更高；5）绿色方法制备了超薄镍铁层状双氢氧化物/泡沫镍（NiFe LDH/NF），表现出高效的析氧催化性能和卓越的结构稳定性。这些电催化材料及其合成策略非常有望在OER和ORR催化中得到广泛的应用。