Tuning the electrode surfaces for better bubble management is a promising approach to increase the efficiency of alkaline water electrolysis. Therefore, Direct Laser Writing was used to structure Nickel electrodes with a dual wetting surface. The applied pillar-like structure combines superhydrophilic behavior and strong spreading of the liquid across the electrode with hydrophobic bubble nucleation sites. In addition, the electrochemically active surface area is increased by a factor of 9. As a result, the overpotential has been significantly reduced, while the size of the detached bubble has increased. The present data set compares three different electrodes, a non-structured reference electrode and two laser structured electrodes with different depths of the structure, at applied current densities of j = -20, -50 and -100 mA/cm² in terms of electrode potential, detached bubble size and number of nucleation sites. As electrolyte 1 M KOH was used. All experiments were carried out under ambient conditions (T = 293 K,p = 1 bar).

Description of Data.zip:

An overview of all performed experiments is given in the file Summary.csv. The data is analyzed as described in the corresponding journal publication How dual wetting electrode surfaces improve electrocatalytic hydrogen evolution. Each data set is stored in a .hdf5-file, with the relevant metadata incorporated into the attributes assigned to the groups/datasets within the .hdf5-file. The data files are structured in groups as follows:

Electrochemical Measurement Data

    Galvanostatic Measurement Data
    CV double-layer capacitance
    LSV onset potential


Results

    Detected Bubbles Sideview


Sideview Raw Images (only for SH2_LS_Pil_01.hdf5)

With the exception of a single comprehensive data set comprising unprocessed images (SH2_LS_Pil_01.hdf5), the remaining raw images from all performed measurements can be made available upon request.

This project is supported by the Federal State of Saxony in terms of the "European Regional Development Fund" (H2-EPF-HZDR), the Helmholtz Association Innovation pool project "Solar Hydrogen", the Hydrogen Lab of the School of Engineering of TU Dresden, and BMBF (project ALKALIMIT, grant no. 03SF0731A).