Li Guopeng, Wen Lisi, Sun Runfeng, Hao Rui
Department of Chemistry and Chemical Engineering, Harbin Institute of Technology 150006 Harbin China.
Department of Chemistry, Southern University of Science and Technology 518055 Shenzhen China
Chem Sci. 2025 Mar 5;16(17):7203-7214. doi: 10.1039/d5sc00189g. eCollection 2025 Apr 30.
Water-air nanointerfaces are essential components of multiphase electrochemical processes in various energy-related applications, including water electrolysis, hydrogen fuel cells, and CO electrochemical reduction. Deep insights into the critical properties of the interfaces are much sought after but very challenging to obtain due to their highly dynamic, transparent, and nanoscopic nature. A new approach has been proposed for constructing stable water-air nanointerfaces using FIB-fabricated Janus nanopore electrodes. The curvature of the nanointerfaces can be controlled electrochemically, ranging from positive (nanodroplets) to negative (nanoconcaves/nanobubbles) ones. The morphologies of different nanointerfaces were fully characterized with AFM. Single-molecule collision events of charged dye molecules, recorded with fluorescence imaging, were used to probe the intrinsic properties of the nanointerfaces. A unique phenomenon of charged dye rejection was discovered for isoelectric nanointerfaces. The role of surface curvature in the collision frequency was also elucidated. We believe that using this platform could be highly beneficial for deepening our understanding of the interfaces, thus guiding the rational design of various energy-related systems.
水-空气纳米界面是各种与能源相关应用中多相电化学过程的重要组成部分，包括水电解、氢燃料电池和CO电化学还原。深入了解这些界面的关键特性备受关注，但由于其高度动态、透明和纳米尺度的性质，获取相关信息极具挑战性。有人提出了一种利用聚焦离子束（FIB）制备的Janus纳米孔电极构建稳定水-空气纳米界面的新方法。纳米界面的曲率可以通过电化学方法进行控制，范围从正曲率（纳米液滴）到负曲率（纳米凹坑/纳米气泡）。利用原子力显微镜（AFM）对不同纳米界面的形态进行了全面表征。通过荧光成像记录带电染料分子的单分子碰撞事件，以此来探测纳米界面的固有特性。在等电纳米界面中发现了一种独特的带电染料排斥现象。同时也阐明了表面曲率在碰撞频率中的作用。我们认为，利用这个平台对于深化我们对这些界面的理解非常有益，从而指导各种与能源相关系统的合理设计。
