Department of Chemistry, Research Institute of Natural Sciences, Incheon National University , 119 Academy-ro, Yeonsu-gu, Incheon, 21022, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Feb 8;9(5):4548-4557. doi: 10.1021/acsami.6b11771. Epub 2017 Jan 30.
Here we describe a facile and scalable method for preparing defect-free graphene sheets exfoliated from graphite using the positively charged polyelectrolyte precursor poly(p-phenylenevinylene) (PPV-pre) as a stabilizer in an aqueous solution. The graphene exfoliated by PPV-pre was apparently stabilized in the solution as a form of graphene/PPV-pre (denoted to GPPV-pre), which remains in a homogeneous dispersion over a year. The thickness values of 300 selected 76% GPPV-pre flakes ranged from 1 to 10 nm, corresponding to between one and a few layers of graphene in the lateral dimensions of 1 to 2 μm. Furthermore, this approach was expected to yield a marked decrease in the density of defects in the electronic conjugation of graphene compared to that of graphene oxide (GO) obtained by Hummers' method. The positively charged GPPV-pre was employed to fabricate a poly(ethylene terephthalate) (PET) electrode layer-by-layer with negatively charged GO, yielding (GPPV-pre/GO) film electrode. The PPV-pre and GO in the (GPPV-pre/GO) films were simultaneously converted using hydroiodic acid vapor to fully conjugated PPV and reduced graphene oxide (RGO), respectively. The electrical conductivity of (GPPV/RGO) multilayer films was 483 S/cm, about three times greater than that of the (PPV/RGO) multilayer films (166 S/cm) comprising RGO (prepared by Hummers method). Furthermore, the superior electrical properties of GPPV were made evident, when comparing the capacitive performances of two supercapacitor systems; (polyaniline PANi/RGO)/(GPPV/RGO)/PET (volumetric capacitance = 216 F/cm; energy density = 19 mWh/cm; maximum power density = 498 W/cm) and (PANi/RGO)/(PPV/RGO)/PET (152 F/cm; 9 mWh/cm; 80 W/cm).
在这里，我们描述了一种简便且可扩展的方法，用于从石墨中制备无缺陷的石墨烯片，该方法使用带正电荷的聚电解质前体聚（对苯乙炔）（PPV-pre）作为稳定剂在水溶液中。用 PPV-pre 剥离的石墨烯显然在溶液中以石墨烯/PPV-pre（表示为 GPPV-pre）的形式稳定存在，这种状态在一年以上的时间内保持均匀分散。从 76%的 GPPV-pre 薄片中随机选取的 300 个薄片的厚度值在 1 到 10nm 之间，这对应于在 1 到 2μm 的横向尺寸上的石墨烯的 1 到几个层。此外，与通过 Hummers 法获得的氧化石墨烯（GO）相比，这种方法有望显著降低石墨烯电子共轭中的缺陷密度。带正电荷的 GPPV-pre 被用于与带负电荷的 GO 一起制备聚对苯二甲酸乙二醇酯（PET）层层组装，得到（GPPV-pre/GO）膜电极。通过氢碘酸蒸气将 PPV-pre 和 GO 同时转化为完全共轭的 PPV 和还原氧化石墨烯（RGO）。（GPPV/RGO）多层膜的电导率为 483 S/cm，约为包含 RGO 的（PPV/RGO）多层膜（166 S/cm）的三倍，RGO 是由 Hummers 法制备的。此外，当比较两个超级电容器系统的电容性能时，GPPV 的卓越的电性能变得明显；（聚苯胺 PANi/RGO）/（GPPV/RGO）/PET（体积电容=216 F/cm；能量密度=19 mWh/cm；最大功率密度=498 W/cm）和（PANi/RGO）/（PPV/RGO）/PET（152 F/cm；9 mWh/cm；80 W/cm）。
