纳米碳材料-贵金属颗粒复合结构的同步辐射原位研究

Hybrid nanomaterials with multi-nanostructures will be effective way for exceeding the performance bottleneck of single nanostructure or nanomaterial. Such study will be multidisciplinary importance for fundamental research as well as for industry. Due to the unique hybrid orbital in carbon atom, there are several allotropes of carbon in nano-scale that have attracted a lot of interests from researchers in the world. Meanwhile, noble metal nanomaterials with interesting physical and chemical properties are broadly used as promising catalysts due to its nano size, large surface and excellent chemical properties. A few efforts have been focused on the hybrid structure of nanocarbon and metal nanoparticles. However, it remains elusive about the real growth mechanism and structure-property relationships. In this project, we select new hybridized nanostructures containing of carbon nanomaterial and noble particles as the research object. Based on unique synchrotron radiation light source, we will develop in-situ XAFS experiment setup and analysis method. Combining with mass spectrometry, UV-vis spectrometry, first-principle calculation method, the project will establish an efficient method to study the nucleation and growth mechanism of various nanocarbon-metal hybrid nanostructures in solution and investigate the evolution form the noble metal precursor to nanoparticles on carbon nanomaterial mediums. The goal of this project is to controllably synthesize noble metal nanoparticles with selective size and crystal face inside or on the surface of various nanocorbons. In combination with electrochemical and others measurements, we will gain deep insight into the intrinsic relationship between various hybrid structures and their catalytic and other performances.

多种纳米材料的有效复合和协同增效有望突破单一纳材料的性能瓶颈。由于碳原子杂化轨道特有的性质，碳元素存在多种同素异构体，低维碳材料一直是纳米材料研究的热点之一。与此同时，贵金属纳米材料由于具有颗粒尺寸小、比表面积较大等优良特性，是目前清洁能源领域普遍采用的金属催化剂。近年来碳材料-贵金属复合结构的合成取得了一定的成功，然而其生长机制和构效关系尚不明了。我们在本项目中选取纳米碳材料和贵金属颗粒复合体系为具体研究对象，依托同步辐射光源，开发适用于XAFS原位表征的液相合成装置和测试方法，结合质谱、UV-vis谱、第一性原理和多重散射理论，研究贵金属纳米晶在碳材料表面和内部的生长动力学过程；重点理解从贵金属先驱体到纳米颗粒的形核生长机制，优化实验设计和合成参数，获得尺寸、晶面可控的纳米碳材料-贵金属颗粒复合新体系。并结合电化学和其他测试手段，揭示不同复合结构与其催化等性能的内在联系。

按照年度计划，项目成员围绕纳米碳材料和贵金属等复合体系的设计、合成和同步辐射表征，逐步开展系统性研究工作。我们已成功地设计和合成了多种高性能的纳米碳基复合材料体系，利用同步辐射X射线吸收谱学手段重点研究了复合新体系的生长过程，并探究了其微观结构和电子结构。结合理论计算，我们逐步建立了复合材料性能与结构之间的内在联系，这些结果可以为新型碳基复合体系的理性设计、可控合成和同步辐射表征提供坚实的基础。相关的研究成果共计发表SCI论文40余篇，包括Advanced Materials（3篇），Advanced Energy Materials（3篇），ACS Nano（2篇），Small（3篇）等。申请中国发明专利2项，并应邀撰写碳基复合材料与同步辐射表征的综述，多次在纳米材料和同步辐射相关的国际会议上做会议报告。此外，本项目执行期间，共培养博士15名（包含5位外国留学生）、硕士6名，其中5位研究生获得国家奖学金，1位博士生获得中国科学技术大学优秀博士论文。目前在读研究生15名、外国留学生3名。在本项目的资助下，项目成员已经形成了纳米材料实验与理论紧密结合、同步辐射技术特色鲜明的青年队伍，为后续的科学研究和项目承担积累了宝贵的研究经验和人员储备。