Bubbles play an important role in (photo)electrolysis. Bubbles can negatively affect overpotentials and block electrodes for the electrolysis reaction. This is not limited to electrolysis but occurs also in other catalytic processes where bubbles are formed. Therefore, it is of great importance to gain a better understanding of the behavior of such bubbles and control the nucleation, growth and movement by design of structured electrodes.
By patterning silicon electrodes we want to create (super)hydrophobic domains on which bubbles can reside. By deliberately controlling the shape of the perimeter, we would like to gain insight in bubble detachment during “unfavoured” pinning positions of the contact line.
To achieve bubble formation we use a simple water splitting reaction which generates gas in the liquid phase until saturation is reached. Continuing the electrolysis will result in the water becoming supersaturated and bubbles are formed on the patterned electrode.
The (super)hydrophobic domains are to be formed with surface functionalization techniques or coating of the silicon surface.
Ultimately we aim to control the detachment size of bubbles with the surface patterning, to increase the efficiency of electrolysis reactions by removing the bubbles at an earlier point in time from the electrodes.
We expect you to work in a multidisciplinairy environment of material science, physics, and chemistry. Studying the recent developments as well as studying the fabrication techniques is expected. Furthermore, the fabrication of the electrodes with hydrophobic and hydrophilic domains, performing electrolysis experiments, and characterization of the electrodes by SEM/AFM is part of the assignment.
Ideally you have background knowledge in material science, advanced technology, physics, or nanotechnology.
Peter van der Linde, PhD student in the Mesoscale Chemical Systems (MCS) group (p.vanderlinde)