Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
1 PublicationHydrogen Bubble Size Distribution on Nanostructured Ni Surfaces: Electrochemically Active Surface Area Versus Wettability
Krause, L.; Skibińska, K.; Rox, H.; Baumann, R.; Marzec, M. M.; Yang, X.; Mutschke, G.; Żabiński, P.; Lasagni, A. F.; Eckert, K.
Abstract
Emerging manufacturing technologies make it possible to design the morphology of electrocatalysts on the nanoscale in order to improve their efficiency in electrolysis processes. The current work investigates the effects of electrode-attached hydrogen bubbles on the performance of electrodes depending on their surface morphology and wettability. Ni-based electrocatalysts with hydrophilic and hydrophobic nanostructures are manufactured by electrodeposition and their surface properties are characterized. Despite a considerably larger electrochemically active surface area, electrochemical analysis reveals that the samples with more pronounced hydrophobic properties perform worse at industrially relevant current densities. High-speed imaging shows significantly larger bubble detachment radii with higher hydrophobicity, meaning that the electrode surface area that is blocked by gas is larger than the area gained by nanostructuring. Furthermore, a slight tendency towards bubble size reduction of 7.5% with an increase in the current density is observed in 1 M KOH.
Keywords: hydrogen evolution; water electrolysis; bubble dynamics; structured electrocatalyst; image analysis
-
ACS Applied Materials and Interfaces 15(2023)14, 18290-18299
DOI: 10.1021/acsami.2c22231
Cited 9 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-37000