Congratulations to Alexander Babich for his successful PhD defense

On 9 April 2025, M.Sc. Alexander Babich successfully defended his dissertation entitled "On the dynamics of electrolytic gas bubbles at microelectrodes". Hydrogen production through water electrolysis is considered a promising technology for a sustainable energy future. A decisive factor for the efficiency of electrolysis is the behaviour of gas bubbles - especially hydrogen and oxygen bubbles - that form at microelectrodes during the process. These bubbles influence important properties such as ion transport, surface reactivity and electrical resistance. In the present work, advanced electrochemical and optical methods (including schlieren imaging and microparticle tracking) were used to experimentally investigate the dynamics of these gas bubbles under normal and microgravity conditions. In particular, the focus was on (i) the temperature fields around hydrogen bubbles and the resulting Marangoni convection, (ii) spontaneous motion reversals of H₂ bubbles, (iii) different growth modes of oxygen bubbles and (iv) the comparison between H₂ and O₂ bubbles under different conditions. The work was supplemented by experiments during a parabolic flight campaign to analyse the behaviour of bubbles in space. The results of this work contribute to the optimisation of electrolysis systems for energy and space applications.