煤基石墨烯的制备及其结构与性能研究

Graphene, a novel carbon material, is a super star because of its unique structure and properties and great potential applications in many high-tech fields. Nevertheless, the low-cost production of graphene materials with tuned structure and properties remains one of the challenges up to now. This project aims to explore the potential of and to develop a new technology for producing high quality graphene materials directly from coal that is a abundant yet cheap carbon source in the world and in China in particular. The effects of a number of parameters on the production of graphene and its derived composite materials will be addressed in detail, including the coal type (with anthracite as a main or focused coal type), coal powder size, maceral type and content in coal, mineral matter/ash content, organic functional groups, volatile matter content and fixde carbon, etc. These efforts will lead to new methodogies for making high quality coal-based graphene materials and their derived composites, of which the governing parameters and the optimized process conditions will be established. The disordered organic structure, i.e. the aromatic building structure unit (ABSU) of coal unit, will be tuned and transformed in terms of the ABSU size and functionality by using catalytic- graphitization technology coupling with acid washing and oxidation, followed by micro-wave and low temperature plasma treatment. The mechanisms involved in these processes will be studied in much detail. The growth and expansion, as well as the self-assembly of ABSU in coal in three dimentional scale under the catalytic graphtization and plasma treatment condtions will be investigated and clarified. This will lead to a new techonlogy for producing graphene materials and their derived composites with tuned structure and functionalities such as graphene/metal/metal oxides composites. The structure, electro-chemical properties and the application potential of the as-made graphene materials and their composites will be explored, and the intrinsic relationship between the coal properties, the process parameters, the structure and the electro-chemcial properties of the as-made graphene materials in terms of applications in supercapacitor and catalysis will be disussed. This project will shed new lights on coal chemistry, coal chemical engineering in terms of low-cost production of graphene materials with tuned structure and properties, and it will give a new impatus on the development of coal science and technology. The idea of making functional graphene materials directly from coal has not been reported in literature except the preliminary results reported by us. This project is surely worth being studied.

结构和性能可调变的廉价石墨烯的可控制备是一个富有挑战性的前沿课题。本项目将研究揭示以煤为原料制备石墨烯的特点和基本规律；诠释煤种、煤粉粒度、显微组分、煤中无机矿物质、有机官能团、挥发份、固定碳等对煤基石墨烯的影响规律，研究构筑煤基石墨烯及其复合纳米结构的新方法及其调控策略。将催化石墨化与酸处理提纯技术耦合，调变煤基本有机结构单元的尺寸及官能团的种类和数量，辅以微波及低温等离子等物理技术手段，实现结构和性能在一定程度上可调控的石墨烯材料的制备；研究揭示催化石墨化及微波和低温等离子体处理等对煤中芳香基本结构单元的芳香层片结构之生长、剪裁、组装及转化的作用机制，阐明石墨化产物的结构特征与其转化反应性间的内在关系；基于煤基石墨烯，构筑石墨烯金属/金属氧化物等纳米复合材料并研究揭示其在超级电容器和催化等领域应用潜力。课题的实施将拓展煤炭精细化深加工利用的新方向，丰富和发展煤化工及石墨烯研究的内涵。

煤炭是自然界富存的以多环芳烃结构单元为主的含碳有机物，在新型碳材料制备中扮演着重要角色。项目以煤为原料，针对煤基石墨烯的可控制备及其在光催化和电化学领域的应用进行了系统研究。重点研究了煤结构对煤石墨化过程的影响，探讨了影响煤基石墨烯结构和性能的主要因素；考察了煤基氧化石墨烯复合材料在CO2光催化过程中的催化特性以及煤基石墨烯复合材料的电化学性能。.在煤基石墨烯制备方面，重点探讨了煤基石墨和煤基石墨烯制备技术，以及影响石墨烯光催化特性和电化学性能的关键因素。研究结果表明：在2500℃及1500℃条件下，催化石墨化技术可以实现煤中有机大分子结构的有序化调变，不同变质程度的煤经催化石墨化后，其产物的石墨化程度也有差异，无烟煤因其有机大分子基本结构单元中芳香层片更大，因此更易石墨化。在应用方面，系统研究了金属及金属氧化物/煤基氧化石墨烯复合材料在CO2光催化还原过程中的应用，研究结果表明：煤基氧化石墨烯结构及特性是影响金属及金属氧化物/煤基氧化石墨烯复合材料的光催化活性和选择性的关键因素，同时，金属及金属氧化物种类，添加量及光源都对复合材料的光催化特性也有很大影响。此外，研究了煤基石墨烯及金属氧化物/煤基石墨烯复合材料在超级电容器电极材料中的应用，分析了煤基石墨烯片层大小和结构缺陷对煤基石墨烯及其复合材料电化学性能的影响。当金属氧化物/煤基石墨烯复合材料用作超级电容器电极材料时，首次充放电的比电容量值相较于煤基石墨烯有了很大提高，而煤基石墨烯的结构不同，其与金属氧化物的协同效应也有差异。.项目系统研究了以不同变质程度煤种制备煤基石墨烯的方法和技术，实现了煤基石墨烯的可控制备并在煤基石墨烯系列材料的应用方面进行了较为深入的研究。结果表明煤基石墨烯在光催化和电化学领域的应用可以与以传统原料制备的石墨烯相媲美，不仅为煤炭的材料化应用开辟了新途径，而且也为石墨烯的宏量可控制备提供了新技术。