A novel electrochemical exfoliation mode was established to prepare graphene sheets efficiently with potential applications in transparent conductive films. The graphite electrode was coated with paraffin to keep the electrochemical exfoliation in confined space in the presence of concentrated sodium hydroxide as the electrolyte, yielding ∼100% low-defect (the D band to G band intensity ratio, I_D/I_G = 0.26) graphene sheets. Furthermore, ozone was first detected with ozone test strips, and the effect of ozone on the exfoliation of graphite foil and the microstructure of the as-prepared graphene sheets was investigated. Findings indicate that upon applying a low voltage (3 V) on the graphite foil partially coated with paraffin wax that the coating can prevent the insufficiently intercalated graphite sheets from prematurely peeling off from the graphite electrode thereby affording few-layer (<5 layers) holey graphene sheets in a yield of as much as 60%. Besides, the ozone generated during the electrochemical exfoliation process plays a crucial role in the exfoliation of graphite, and the amount of defect in the as-prepared graphene sheets is dependent on electrolytic potential and electrode distance. Moreover, the graphene-based transparent conductive films prepared by simple modified vacuum filtration exhibit an excellent transparency and a low sheet resistance after being treated with NH₄NO₃ and annealing (∼1.21 kΩ/□ at ∼72.4% transmittance).

中文翻译：

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受限空间中石墨的电化学剥落制备石墨烯片及其在透明导电膜中的应用

建立了一种新型的电化学剥落模式，可以有效地制备石墨烯片，并将其潜在地应用于透明导电膜中。石墨电极涂有石蜡以在浓氢氧化钠作为电解质存在的情况下将电化学剥落保持在狭窄的空间内，产生约100％的低缺陷（D谱带与G谱带的强度比，I _D / I _G＝ 0.26）的石墨烯片。此外，首先用臭氧试纸检测臭氧，并研究了臭氧对石墨箔的剥离和所制备的石墨烯片的微观结构的影响。结果表明，在部分涂有石蜡的石墨箔上施加低电压（3 V）时，该涂层可防止嵌入不足的石墨片过早地从石墨电极上剥落，从而提供少层（<5层）的多孔性石墨烯片的产率高达60％。此外，在电化学剥离过程中产生的臭氧在石墨的剥离中起着至关重要的作用，所制备的石墨烯片中的缺陷量取决于电解电位和电极距离。而且，₄ NO ₃和退火（在约72.4％的透射率下为约1.21kΩ/□）。