Abstract We report on the study of the electrochemical behavior of liquid exfoliated graphene nanosheets (GS) with varied sizes and thickness by controlling centrifugal speed. GS were prepared via a solvent exfoliation and centrifugation separation method from graphite powder using N-methyl-2-pyrrolidone (NMP) as the solvent and with the assistance of sodium citrate. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra, UV–Vis spectra and particle size measurements were employed to characterize the size and structural changes of GS under different centrifugal speeds. And, the electrochemical properties of these GS materials like redox behaviors, standard heterogeneous rate constant (k0) and electrochemical impedance were studied using potassium ferricyanide as the probe. Our results suggested that the size and concentration show obvious effects on the electrochemical properties of the solvent exfoliated GS.

中文翻译：

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通过基于离心速度的分级调整 N-甲基-2-吡咯烷酮液体剥离石墨烯纳米片的电化学行为

摘要 我们报告了通过控制离心速度研究不同尺寸和厚度的液体剥离石墨烯纳米片 (GS) 的电化学行为。以 N-甲基-2-吡咯烷酮 (NMP) 为溶剂，在柠檬酸钠的辅助下，通过溶剂剥离和离心分离法从石墨粉中制备 GS。采用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、拉曼光谱、UV-Vis 光谱和粒度测量来表征不同离心速度下 GS 的尺寸和结构变化。并且，使用铁氰化钾作为探针研究了这些 GS 材料的电化学性质，如氧化还原行为、标准异相速率常数 (k0) 和电化学阻抗。