Tracking structural changes of Ni/Fe3O4 model electrodes during the Oxygen Evolution Reaction (OER) using High Energy Surface X-ray Diffract

The aim of this experiment is to use HESXRD for the operando study of atomic-scale structural changes of Fe3O4(001) and Fe3O4(111) thin film model electrodes decorated by Ni nanoparticles of varying size during potentiostatic and potentiodynamic OER conditions. Special focus will be put on the expected strain effects in the the oxide films during pulse electrolysis conditions. The systematically probed parameter space (different Ni nanoparticle sizes and different surface orientations) will yield new insight into the correlation between the potential-dependent Ni nanoparticle sintering, the strain/stress effects in the Fe3O4 thin films, the synergy effects between Fe and Ni toward the catalytic properties, and the model electrode stability, both under potentiostatic and potentiodynamic OER conditions. The results will pave the way to a knowledge-based synthesis of improved and robust precious-metal free electrode materials for the water-splitting reaction.