20.500.12556/RUL-182854 Hydrogen bubble growth on platinum microelectrode: effects of electrode diameter, electrolyte concentration, and surface texturing Hydrogen bubble dynamics on microelectrodes strongly influence the performance and durability of electrochemical devices, yet the combined effects of electrode diameter, electrolyte concentration, and surface texturing remain insufficiently understood. In this study, we systematically investigate the growth, detachment, and regime transitions of electrolytically generated hydrogen bubbles on untextured (polished) and laser-textured platinum microelectrodes with diameters of 50, 100, and 200 μm in sulfuric acid solutions with concentrations between 0.05 and 1.00 ▫$molL^{−1}$▫. Synchronized high-speed imaging and potentiostatic measurements are used to identify four reproducible regimes: (I) isolated bubble growth without coalescence, (II) limited lateral coalescence, (III) a single coalesced bubble, and (IV) a pinned single coalesced bubble. A regime map constructed in the parameter space of applied potential, electrolyte concentration, and electrode diameter reveals that increasing ▫$H_{2}SO_{4}$▫ concentration and decreasing electrode diameter promote earlier onset of coalescence and pinning. The detachment diameter increases with applied potential under most conditions, while the current–density response reflects a balance between increasing driving force and bubble-induced surface shielding. For the 200 μm electrode, an optimal operating window is identified at intermediate electrolyte concentration (∼0.5 ▫$molL^{−1}$▫), where high current density can be sustained to higher potentials before the onset of persistent pinning. In addition, an empirical, diffusion-inspired correlation is proposed for the detachment diameter on the untextured 200 μm electrode, providing a compact description of its dependence on potential and electrolyte concentration within the monotonic regime. Surface texturing significantly modifies bubble dynamics by reducing nucleation overpotential and delaying the onset of persistent pinning by ∼ 2.3 V, resulting in higher current densities at high applied potentials. Overall, the results establish a unified framework linking bubble dynamics, operating conditions, and electrochemical performance, and provide practical guidance for the design of efficient microstructured electrochemical systems. hydrogen bubble coalescence textured platinum microelectrode enhanced electrolysis hydrogen evolution reaction vodik koalescenca mehurčkov tekturiranje platinaste mikroelektrode izboljšanje učinkovitosti elektrolize reakcija razvoja vodika true false true Angleški jezik Slovenski jezik Članek v reviji 2026-05-26 07:43:12 2026-05-26 07:43:23 2026-05-27 04:39:57 0000-00-00 00:00:00 2026 0 0 16 str. Vol. 176, art. 111776 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 532.52:544.6.076.32 0894-1777 10.1016/j.expthermflusci.2026.111776 278977027 Arhar...Hydrogen_bubble....pdf Arhar...Hydrogen_bubble....pdf 1 8BFFB3E10ED787A2C86A2A142A12C7B5 f48024bf9e8b5265c183f689f5b39f0fa4ce74e87ab5340c5bbe4b9f96ed44a5 94f717d8-58c6-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=234458 https://www.sciencedirect.com/science/article/pii/S0894177726000889 1 7b4eab68-58c5-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=234457 Fakulteta za strojništvo 0 0 0