Jin Yuankai, Yang Siyan, Sun Mingzi, Gao Shouwei, Cheng Yaqi, Wu Chenyang, Xu Zhenyu, Guo Yunting, Xu Wanghuai, Gao Xuefeng, Wang Steven, Huang Bolong, Wang Zuankai
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, PR China.
Department of Mechanical Engineering, City University of Hong Kong, Hong Kong SAR, PR China.
Nat Commun. 2024 Jun 4;15(1):4762. doi: 10.1038/s41467-024-49088-1.
Liquid-solid contact electrification (CE) is essential to diverse applications. Exploiting its full implementation requires an in-depth understanding and fine-grained control of charge carriers (electrons and/or ions) during CE. Here, we decouple the electrons and ions during liquid-solid CE by designing binary superhydrophobic surfaces that eliminate liquid and ion residues on the surfaces and simultaneously enable us to regulate surface properties, namely work function, to control electron transfers. We find the existence of a linear relationship between the work function of superhydrophobic surfaces and the as-generated charges in liquids, implying that liquid-solid CE arises from electron transfer due to the work function difference between two contacting surfaces. We also rule out the possibility of ion transfer during CE occurring on superhydrophobic surfaces by proving the absence of ions on superhydrophobic surfaces after contact with ion-enriched acidic, alkaline, and salt liquids. Our findings stand in contrast to existing liquid-solid CE studies, and the new insights learned offer the potential to explore more applications.
液-固接触起电（CE）对于多种应用至关重要。要充分利用它，需要在CE过程中深入理解并精细控制电荷载流子（电子和/或离子）。在此，我们通过设计二元超疏水表面，在液-固CE过程中分离电子和离子，该表面能消除表面的液体和离子残留，同时使我们能够调节表面性质，即功函数，以控制电子转移。我们发现超疏水表面的功函数与液体中产生的电荷之间存在线性关系，这意味着液-固CE是由于两个接触表面之间的功函数差异导致的电子转移引起的。我们还通过证明与富含离子的酸性、碱性和盐溶液接触后超疏水表面上不存在离子，排除了在超疏水表面上CE过程中离子转移的可能性。我们的发现与现有的液-固CE研究形成对比，所获得的新见解为探索更多应用提供了潜力。
