Among various methods to produce graphene sheets, electrochemical exfoliation has been regarded as an effective method for the mass production of high-quality graphene sheets because of its simplicity and environmental friendliness. However, conventional electrochemical exfoliation has a disadvantage of accumulating intercalating ions at graphite interlayers owing to the use of a constant voltage. In this study, we developed a DC switching technique to achieve more efficient intercalation of ions than that in the conventional method. In the DC switching method, positive and negative voltages are successively applied to release the accumulated intercalating ions. By testing various conditions, we found the optimum switching time to produce high-quality graphene sheets with the highest yield rate and the highest electrical conductivity. As a result, the graphene sheets using this DC switching technique showed 85% higher yield rate, 193% higher electrical conductivity, 160% larger area, and 25% thinner thickness than those obtained when using a constant DC method. We believe that this DC switching technique can be used for large-scale production of high-quality graphene sheets.

中文翻译：

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使用直流开关电压制备电化学剥离的石墨烯片

在生产石墨烯片的各种方法中，电化学剥离由于其简单性和环境友好性而被认为是大规模生产高质量石墨烯片的有效方法。然而，由于使用恒定电压，常规的电化学剥离具有在石墨夹层处积累嵌入离子的缺点。在这项研究中，我们开发了一种直流开关技术，以实现比传统方法更有效的离子嵌入。在DC开关方法中，连续施加正电压和负电压以释放累积的嵌入离子。通过测试各种条件，我们发现了最佳的转换时间，可以生产出具有最高产率和最高电导率的高质量石墨烯片。结果是，与使用恒定DC方法获得的石墨烯片相比，使用这种DC开关技术的石墨烯片显示出高出85％的产率，193％的电导率，160％的更大面积和更薄的25％的厚度。我们相信，这种直流开关技术可用于大规模生产高质量石墨烯片。