文献类型：期刊文献

英文题名：Bubble-driven convection induces delayed potential response in constant-current hydrogen evolution

作者：Wu, Tao[1];Yuan, Fang[1];Yang, Zixian[1];Liu, Bo[1];Yang, Qiang[1]

机构：[1]East China Univ Sci & Technol, Dept Mech & Power Engn, Shanghai, Peoples R China

年份：2025

卷号：541

外文期刊名：ELECTROCHIMICA ACTA

收录：;EI(收录号：20253719167477);WOS:【SCI-EXPANDED(收录号:WOS:001583564100002)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Grant.Nos.52025103, 22178099) , the Shanghai Natural Science Foundation (Grant.No.21ZR1417000) , the Shanghai Pilot Program for Basic Research (Grant. No. 22TQ1400100-11) and the Special Project for Peak Carbon Dioxide Emissions-Carbon Neutrality (Grant.No.21DZ1207800) from the Shanghai Municipal Science and Technology Commission.

语种：英文

外文关键词：Hydrogen evolution reaction; Bubble detachment dynamics; Potential oscillation; Local concentration overpotential; Mass transfer

摘要：Gas evolution during the hydrogen evolution reaction (HER) induces complex interfacial dynamics and can lead to oscillations in potential. However, the real-time coupling between bubble behavior and overpotential response remains poorly understood. In this study, we report a previously unrecognized delay phenomenon during constant-current HER: the minimum in overpotential does not coincide with the moment of bubble detachment, but instead occurs tens of milliseconds later-after a new bubble has already formed and grown to several hundred microns on the electrode surface. Using synchronized high-speed imaging and time-resolved electrochemical measurements, we show that the delay time increases consistently with current density and bubble detachment size. Statistical analysis across multiple cycles confirms strong correlations among detachment size, oscillation amplitude, and delay time. Notably, in rare cases involving successive bubble detachments, both the delay and amplitude are further amplified. Complementary CFD simulations confirm that bubble wake generates transient interfacial convection, which significantly enhances local mass transfer and temporarily reduces the concentration overpotential, thereby delaying the recovery of reaction potential even as a surface new bubble begins to grow on electrode. These findings unveil a previously unrecognized dynamic feedback mechanism in which gas bubble evolution actively modulates interfacial mass transfer, offering new insight into gas-involved electrochemical processes and a potential strategy for optimizing multiphase electrochemical systems.