氮掺杂石墨烯制备及其应用研究进展

Recent Advances in the Synthesis and Applications of Nitrogen-Doped Graphene

摘要: 石墨烯作为物理、化学、生物医药、材料科学等学科领域的一大研究热点，它存在以下几个方面的局限性而在一定程度上限制了它的广泛应用：1) 理想石墨烯材料具有的零带隙电子结构限制了它在光电领域的应用，2) 具有高表面能的石墨烯片层极易团聚而致使其散失所特有的诸多优异性能，3) 由于与其它材料的界面结合牢度不够，表面呈现惰性的石墨烯片层不易与其它材料复合。为了使石墨烯材料获得更加广泛的应用，功能化改性处理一直都被作为一个研究热点而被广泛深入研究。功能化石墨烯不仅可以利用石墨烯诸多本征优异性能，还可以赋予其新的结构及功能，从而实现更广泛的应用。调控石墨烯物理化学性质的热门方法之一是通过利用像无机非金属原子等异质原子进行掺杂处理，使石墨烯重组子晶格结构，打破其原有的对称性和规则嵌套结构。氮原子具有相比于其它无机非金属原子更接近碳原子的大小，故与石墨烯有着更好的相容性，易于掺杂进入石墨烯的晶格中而获得稳定的氮掺杂石墨烯(NG)材料。更重要的是，氮元素的掺入将会产生N-C键，其中毗邻N原子的C原子将会带有更多的正电荷，从而能有效增强石墨烯材料的电负性，这种电子吸附性的增强可为氧化还原反应创造更佳的催化条件，这些特性使得NG的研究及应用成为了各领域的重要方向。本论文综述了近几年NG的制备方法，分析比较了各制备方法的优缺点，并对其现阶段研究瓶颈问题和在催化、超级电容器、光催化、生物传感、抗菌等应用方向进行了总结性展望。本综述论文将为开发更多高性能NG基材料用于解决各科技和工业领域基础理论和实际技术问题和挑战具有一定参考价值。

Abstract: As the focus of much attention in multi-disciplinary fields such as physics, chemistry, biomedicine, and materials science, graphene has the following limitations which impede their widespread ap-plications: 1) the gapless electronic structure of graphene would retard their optoelectronic ap-plications, 2) the high surface energy of graphene nanosheets causes them to readily aggregate, consequently losing their unique properties, and 3) the inert surface of graphene makes it difficult to combine with other materials. In order to realize more widespread applications of graphene, it is essential to functionalize graphene physically or chemically, and graphene functionalization is a broad subject being undergoing an intense study. This is because the functionalization cannot only retain the unique intrinsic properties of graphene to a certain extent but also impart new struc-tures and properties to the functionalized graphene. Doping with heteroatoms is one of the most hot-topic research areas regarding the functionalization of graphene, which leads to the breakage of the original symmetry and ordered honeycomb structure and to the rearrangement of the crystal structure of graphene. Compared to other non-metal heteroatoms, nitrogen has a size closer to carbon, revealing a higher compatibility of nitrogen with the lattice structure of graphene. Hence, nitrogen can be more easily doped into the graphene lattices, producing nitrogen-doped graphene (NG) that is more stable in comparison with other heteroatom-doped graphene. More importantly, the incorporation of nitrogen would enhance the electronegativity of graphene materials, attributed to the generated N-C bond where the adjacent carbon atoms are endowed with more positive charges. The enhancement of the electronegativity facilitates catalytic redox reactions. These characteristics of NG lead the research and applications of NG to become an important direction in various fields. This review article summarizes various NG preparation methods in recent years, and compares the merits and demerits of these preparation methods. In addition, the applications of NG in catalysis, supercapacitors, photocatalysis, biosensing, and antibacterial, etc., are reviewed, and the bottleneck in the current stage and the future prospect are also pointed out. The review paper presented here paves the way for the development of more high-performance NG-based materials for addressing both fundamental and technical problems and challenges in both scientific and industrial communities.