• 文献标题:   Size-controlled synthesis of urchin-like reduced graphene oxide microspheres with highly packed density by emulsion-assisted in-situ assembly and their supercapacitor performance
  • 文献类型:   Article
  • 作  者:   YUE F, GAO GQ, LI FT, ZHENG YQ, HOU SF
  • 作者关键词:  
  • 出版物名称:   CARBON
  • ISSN:   0008-6223 EI 1873-3891
  • 通讯作者地址:   Shandong Univ
  • 被引频次:   5
  • DOI:   10.1016/j.carbon.2018.03.074
  • 出版年:   2018

▎ 摘  要

We report a facile water-in-oil (W/O) emulsion method to fabricate urchin-like reduced graphene oxide microspheres (UrGOMSs) with tunable sizes and structures. The success of this synthesis relies on the use of polyethyleneimine and ethylenediamine, acted as an emulsifier and weak crosslinker, respectively, to assist the formation of graphene hydrogel in emulsion droplets, followed by thermal treatment to remove the water. The diameter of the UrGOMSs could be controlled in the range of 2.30-4.58 mm by varying the water-oil ratio and thus the size of emulsion droplets. The UrGOMSs show crumpled surface and urchin-like structure with assembly of graphene nanosheets, which can supply large amount of accessible surface area and efficient ion diffusion pathways. The specific surface area of the structures is up to 356.33 m(2) g(-1) with high pack density of 1.37 g cm(-3). When used as electrode materials in super-capacitors, the UrGOMSs exhibit high volumetric capacitance of 527.6 F cm(-3) at 10 mV s(-1) and 452.1 F cm(-3) at 0.2 A g(-1). Furthermore, they also exhibit excellent long-term cycling stability. After 5000 cycles, the capacity retention is around 99.43%. These results indicate the feasibility of the novel strategy for designing densely assembled graphene microspheres for supercapacitors. (C) 2018 Elsevier Ltd. All rights reserved.