等离子体对石墨烯的功能化改性

Graphene modification based on plasma technologies

等离子体态物质富含高反应活性粒子群,包括电子、离子、自由基、光子等,是催化或直接参与化学反应的重要因子,在化学合成与材料改性领域有重要应用价值,往往可以使热平衡条件下难以发生,甚至不能发生的化学反应,在等离子体催化下得以发生和加速.常规条件下的石墨烯就是低反应活性物质,往往需要在高温甚至高压和强酸强碱条件下才能发生化学反应,对于新型石墨烯衍生材料的合成与改性是一个束缚.而等离子体催化石墨烯反应,可以在常温常压无腐蚀性条件下,引发石墨烯的还原、氧化、缺陷修复、掺杂、接枝、外延生长和交联等一系列化学反应,为石墨烯功能化改性及其新型复合材料合成提供了更多可能性,值得深入探索.过去十多年,等离子体在石墨烯合成与改性方面的研究报道并不鲜见,特色鲜明,然而,较多的报道停留在技术路线的尝试以及结果呈现层面,化学反应动力学研究鲜有涉及,本文对这些研究报道进行综合论述,主要是对部分代表性研究结果的再报告和总结性讨论,旨在促进相关领域的深入研究.

Plasma contains highly reactive species,including electrons,ions,radicals,photons,etc.,which are critical for catalyzing or directly participating in chemical reactions.Plasma is a highly efficient tool in chemical synthesis and material modification,since it can make the chemical reactions that are difficult or even impossible to occur under thermal equilibrium conditions take place and accelerate through its catalysis.The chemical reactivity of graphene under conventional conditions is low,which means that the reaction of graphene requires high temperature,high pressure and/or strong acid or alkali,thereby restricting the synthesis and modification of novel graphene-derived materials.Plasma-assisted graphene reaction can trigger a series of chemical reactions,such as reduction,oxidation,defect repair,doping,grafting,epitaxial growth and crosslinking of graphene,under ambient temperature and pressure without any corrosive conditions.It provides great potentials for the functional modification of graphene and the synthesis of graphene composites,which deserve further exploration.Over the past decade,a number of studies of graphene synthesis and modification by using plasma with distinctive characteristics have been reported.However,most of reports focused on the presentation of technical routes and corresponding results,and the research on chemical reaction kinetics is still far from being fully addressed.In this review,we make a comprehensive discussion about these reports by mainly summarizing and discussing some of the representative results,in order to promote further research in the relevant fields.