Generation of electric potential by the flow of an electrolyte droplet on a graphene surface is investigated to develop a liquid motion energy harvester. Most of the research efforts to date have been focused on unveiling the interaction between graphene and an electrolyte droplet. However, other factors that significantly affect the output potential have not been paid much attention. Here, we report the electrostatic charging of graphene during a layer-transfer process and its influence on the enhancement of the performance of graphene-based liquid motion energy harvesting devices. In particular, we investigated the dependence of the output voltage on the triboelectric properties of the substrate. Our finding indicates that the triboelectric surface charging of graphene is significantly influenced by physisorption between graphene and the underlying substrate. Therefore, it directly affects the output power generation and the concentration of electrolyte solution at which the maximum power generation can be achieved. The method presented here is a simple route to further improve the output performance of graphene-based liquid motion energy harvesting devices and this study extends the physical understanding of charge interaction between graphene and an electrolyte solution.

研究了通过在石墨烯表面上的电解质液滴的流动产生电势以开发液体运动能量收集器。迄今为止，大多数研究工作都集中在揭示石墨烯与电解质液滴之间的相互作用上。但是，其他对输出潜力有重大影响的因素并未引起足够的重视。在这里，我们报告了石墨烯在层转移过程中的静电荷及其对增强石墨烯基液体运动能量收集装置性能的影响。特别是，我们研究了输出电压对基板摩擦电性能的依赖性。我们的发现表明，石墨烯的摩擦电表面电荷受石墨烯与下面的基底之间的物理吸附作用显着影响。因此，它直接影响输出功率的产生和可以实现最大功率产生的电解质溶液的浓度。本文介绍的方法是进一步改善基于石墨烯的液体运动能量收集装置的输出性能的简单途径，并且该研究扩展了对石墨烯与电解质溶液之间电荷相互作用的物理理解。