Abstract Graphene edges, as opposed to the basal plane of graphene, present extremely high chemical reactivity due to their unique electronic state near the Fermi level, showing great promises for applications in electrochemical energy storage, electrocatalysis and contaminants adsorption. However, graphene edges are sparsely exposed due to the high aspect ratio and 2D nanosheet morphology of graphene materials. Herein, we report the surface graphenization of carbon with abundant exposed graphene edges by carbonizing organic polymer in ammonia. The formation of such unique structure is attributed to the preferable etching of ammonia on the flat (002) planes than the vertical ones. Resultantly, few-layered graphene with sharp edges is perpendicularly formed and fixed on the carbon surface without agglomeration. This unique edge structure contributes to a high specific surface area of 2150 m2 g-1 with a large pore volume of 1.5 cm3 g-1 of carbon, exceeding most of commercially available activated carbons but avoiding the use of the awkward KOH. The high surface area of carbon, together with highly reactive graphene edges, provides numerous sites for ion storage and adsorption. It exhibits a high energy density of 68.16 Wh kg-1 in ionic liquid-based symmetric supercapacitor and presents superior adsorption capabilities toward various organic contaminants including dyes, organic solvents and oils, especially methylene blue (961.3 mg g-1). Our finding proves the feasibility of surface graphenization of carbon and provides a new way to enhance the surface reactivity of functional carbon materials.

中文翻译：

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通过在氨气中碳化有机前驱体原位形成 3D 垂直石墨烯

摘要 与石墨烯的基面相反，石墨烯边缘由于其在费米能级附近的独特电子态而表现出极高的化学反应性，在电化学储能、电催化和污染物吸附方面的应用前景广阔。然而，由于石墨烯材料的高纵横比和二维纳米片形态，石墨烯边缘稀疏暴露。在此，我们报告了通过在氨中碳化有机聚合物来实现具有大量暴露石墨烯边缘的碳的表面石墨化。这种独特结构的形成归因于氨在平面 (002) 平面上的蚀刻比垂直平面更好。结果，具有锋利边缘的少层石墨烯垂直形成并固定在碳表面上而没有团聚。这种独特的边缘结构有助于实现 2150 m2 g-1 的高比表面积和 1.5 cm3 g-1 的大孔体积的碳，超过大多数市售活性炭，但避免使用尴尬的 KOH。碳的高表面积以及高反应性石墨烯边缘为离子存储和吸附提供了许多位点。它在基于离子液体的对称超级电容器中表现出 68.16 Wh kg-1 的高能量密度，并对包括染料、有机溶剂和油在内的各种有机污染物表现出优异的吸附能力，尤其是亚甲蓝 (961.3 mg g-1)。我们的发现证明了碳表面石墨化的可行性，并为增强功能性碳材料的表面反应性提供了一种新方法。