石墨烯的光化學修飾方法, 化學學報, 2014, 72（3）, 289-300
石墨烯的光化學修飾方法
周琳, 張黎明, 廖磊, 楊明媚, 謝芹, 彭海琳, 劉志榮, 劉忠範
beat365納米化學研究中心 beat365官方网站 北京 100871
Photochemical Modification of Graphene
Zhou Lin, Zhang Liming, Liao Lei, Yang Mingmei, Xie Qin, Peng Hailin, Liu Zhirong, Liu Zhongfan
Center for Nanochemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871
摘要
石墨烯是由sp2雜化碳原子組成的具有蜂窩狀結構的二維原子晶體. 石墨烯的共價化學修飾是石墨烯研究領域的一個新的熱點，也是石墨烯材料的表面改性和能帶調控、以及合成新型二維石墨烯衍生物的重要途徑. 完整的二維蜂窩結構和離域大p鍵使得石墨烯的化學性質非常穩定，難以通過常規的化學反應獲得高效的表面修飾，這是石墨烯共價化學的主要挑戰. 近年來，我們發展了一系列基于光化學原理的石墨烯共價修飾方法，利用光化學過程産生的活性自由基實現了石墨烯的高效共價加成和氧化反應，為石墨烯的光化學能帶工程奠定了理論和實驗基礎. 本文将以這些研究成果為主線，系統地闡述石墨烯的光化學修飾方法及其二維反應特性，并對該領域的未來發展趨勢和所面臨的挑戰進行簡要的展望.
關鍵詞 ： 石墨烯, 光化學, 自由基, 光氯化, 光催化, 非對稱修飾
Abstract
Graphene, a two-dimensional (2D) atomic crystal composed of single-layer hexagonal mesh of carbon atoms, is one of the most exciting materials being investigated today. Graphene chemistry, the covalent functionalization of graphene as a giant molecule, provides a promising approach to controllably engineer graphene's band structure, create novel graphene derivatives and tailor the interfacial characteristics. One of the great challenges for graphene functionalization originates from its strong chemical stability, thus highly reactive chemical species are needed as the reactants. In recent years, we have been working on the photo-induced free radicals-based photochemistry of graphene, targeting the efficient graphene functionalization for its band structure engineering. Various photochemical modification methods have been developed, such as photochemical chlorination, photochemical methylation, photocatalytic oxidation and bifacially asymmetric functionalization of graphene. The homogeneous and nondestructive photochlorination of graphene could remove the conducting π-bands and open up a band gap in graphene. TiO2-based photocatalytic oxidation of graphene could realize photochemical tailoring of graphene, including ribbon cutting, arbitrary patterning on any substrate, layer-by-layer thinning, and localized graphene to graphene oxidation conversion. Using photochemical reaction of graphene as a probe, we have investigated the dimension effects on graphene chemistry, including the thickness, stacking order, single- and double-side, and edge dependent reactivity in graphene. After two-step functionalization of graphene, we have fabricated the thinnest Janus disc named Janus graphene, which comprises two kinds of decorations separated by the one-atom-thick carbon layer. It is found that chemical decorations on one side are capable of affecting both chemical reactivity and wettability of the opposite side, indicative of communication between the two grafted decorations separated by a single-layer graphene. In this review, we select several typical examples to demonstrate such kinds of photochemical graphene engineering and its intrinsic 2D reaction characteristics, together with a brief discussion on the future directions, challenges and opportunities in this research area.
Key words： graphene photochemistry free radical photochlorination photocatalysis asymmetric functionalization
http://sioc-journal.cn/Jwk_hxxb/CN/abstract/abstract343639.shtml
