调控与功能化钼基硫硒化物分等级复合材料及电催化析氢机理研究

Hydrogen fuel as a green energy resource has attracted the widespread attention of scientific community because of its high energy, non-pollution and renewable characteristics. Highly efficient and inexpensive molybdenum-based functional materials have some special advantages in electrocatalytic hydrogen evolution field, such as molybdenum dioxide possesses higher conductivity, selenium vacancies in molybdenum diselenide have lower hydrogen adsorption Gibbs free energy, the edges of molybdenum-based chalcogenides of particularly layered structure have abundantly catalytic active sites and so on. Therefore, the molybdenum-based sulfides and selenides will display outstanding performance advantage in electrocatalytic hydrogen evolution field through designing special structure, recombination, doping, and so on ways to regulate and control them combined with these peculiar properties of molybdenum-based materials. From investigation and regulation of different substrate surface energies and reactivities this project proposes and adopts chemical vapor deposition method combined with confined space and near steady state source techniques, which can control the preparation of three-dimensional hierarchically molybdenum-based sulfide and selenide composite nanomaterials with high quality, novel structure and uniform scale. The carbon nanotubes and graphene quantum dots are doped into the molybdenum-based materials. This project also investigates the formation process and growth mechanism, clarifies the regulation rule of the substrate, and explores the influence law and internal mechanism of the structure and composition on the electrocatalytic hydrogen evolution performance, and establishes relational model. The implementation of this project will lay a foundation for related research fields.

氢燃料作为一种绿色能源，由于其能量高、无污染和可再生等特点，引起了科学界的广泛关注。高效廉价的钼基功能材料，在电催化析氢领域具有一些独特的优势，如二氧化钼的导电性较高、二硒化钼中的硒空位氢吸附吉布斯自由能较低、特有层状结构的钼基硫属化物边缘存在丰富的催化活性位点等。因而，利用钼基材料这些独特的性质，通过设计特殊的结构，采用复合、掺杂等方法对其进行调控与功能化，将使钼基硫硒化物在电催化析氢领域展示出色的性能优势。本项目从对不同基底表面能与反应活性的研究和调控出发，提出采用化学气相沉积方法结合限域空间与近稳态源技术，可控制备质量高、结构新颖、尺度均一的三维分等级钼基硫硒化物复合纳米材料，在钼基材料中掺杂引入碳纳米管和石墨烯量子点，研究其形成过程和生长机理，阐明基底调控规律，探索结构、组成等对电催化析氢性能的影响规律和内在机制，并建立关系模型。本项目的实施将为相关领域的研究奠定基础。

社会经济的快速发展使人类对能源的需求急剧增加，能源短缺问题也日益加剧。人类对能源的思维处置方式需要从收集转变为生产。第一，努力开发与探索可再生新型绿色能源，如氢能能量密度高、绿色无污染、可再生等优势；第二，研究利用能源的核心基础是转换和存储器件，如超级电容器充放电速率快、比电容高、寿命长、能量密度高等特点。当前二维层状纳米材料研究热度非常高，特殊的层状结构使其表现出各异的物理化学性质和多种杰出的性能，高效廉价易得的过渡金属钼钴层状功能活性材料在电催化析氢和超级电容器领域展示了优异的特质，通过不同技术手段相结合的方式设计和调控生长过程，使其具有独特的形貌、结构和组成，利用复合、取代等策略优化钼钴层状功能材料，使其表现优异的性能，将在能源领域意义重大。本项目可控合成了高质量、均匀尺寸、特殊结构、良好分散性的三维分等级垂直MoSe2纳米层、超小MoSe2纳米晶、分等级Co(OH)2/CoSe2异质结纳米阵列和核壳分等级CoFe2Se4@CoFe2O4和CoFe2S4@CoFe2O4纳米盒等不同功能活性材料，这些材料在电化学领域展示了出色的性能，如电催化析氢和超级电容器，同时研究了形成过程、影响因素及其机理机制。本研究项目的实施结果将为电化学相关领域的进一步探索奠定坚实的基础。