Oxidation and disorder in few-layered graphene induced by the electron-beam irradiation

Zhiwei Xu, Lei Chen, Jialu Li, Rui Wang, Xiaoming Qian, Xiaoyan Song, Liangsen Liu, Guangwei Chen
2011 Applied Physics Letters  
Structural changes caused by an electron beam with the high irradiation energy of 5 MeV were investigated in few-layered graphene. Both the original and the irradiated few-layered graphene were characterized by x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy. It was found that a typical diffraction peak of graphene oxide emerged and this may be attributed to a partial oxidation in few-layered graphene which was induced by the irradiation. In addition, the graphitic
more » ... on, the graphitic structure of few-layered graphene was found to be disordered according to the increased intensity ratio of D to G band. Graphene, a single atomic layer of sp 2 -hybridized carbon, has attracted tremendous attention owing to its strictly two-dimensional structure and a wide range of unusual properties. Graphene research has developed at a truly relentless pace. 1-6 Few-layered graphene ͑FLG͒, which is composed of several individual graphene layers, is now also under intensive investigation. 7 Transmission electron microscope is undoubtedly a useful tool for investigation of free standing graphene sheet, but has the disadvantage that structural alterations of the specimen by inevitable electron irradiation can be severe and lead to misinterpretations. 8,9 Moreover, electron irradiation can be deliberately used to alter the chemical, mechanical, and electronic properties of nanomaterials. The problem of changes in graphene lattice induced by the low and medium energy electron-beam irradiation was originally addressed by Teweldebrhan and Balandin. 10 The structure and electrical properties of graphene were also found to be tuned by the medium energy electron-beam irradiation. [11] [12] [13] [14] [15] [16] In this letter, FLG was irradiated by an electron beam with the high energy of 5 MeV. The structural changes were in-vestigated and the alterations of functional group percent were illustrated. FLG was synthesized with the method of chemical exfoliation 17 and provided by Nanjing Xianfeng Nano Com. Ltd., China. The irradiation was performed by an industrial BF-5 electron accelerator operating at 5 MeV, with a fluence of 5.01 C / cm 2 and a beam current of 200 A in ambient a͒
doi:10.1063/1.3587798 fatcat:jpxwltwdcnffndulylopp6ggaq