Photoelectrochemical (PEC) water splitting is promising for energy storage and generation of green fuels (for example H2). The photoanode, often based on silicon, suffers from corrosion under basic conditions, and protection layers have to be applied to allow for long-term stability. As shown in various studies, TiO2 appears to be a suited protective material, however its poor electrical conductivity is a drawback. In this project I focus on the electrochemical modification of TiO2 to generate substoichiometric TiOx layers with enhanced electrical conductivity. In addition, the TiOx will be further modified with a suitable electrocatalyst to allow for sustained oxygen evolution (OER).