Titanium dioxide electrodes for water photo-electrolysis: modelling of photoelectrochemical processes

Abstract

Solar photoelectrolysis of water is considered as a promising route towards green hydrogen production. Since its first demonstration in 1969 [1], improving the efficiency of the process remains the major challenge. Current research efforts focus on the development of improved photoelectrodes enabling higher photocurrents and larger solar-to-hydrogen conversion. Of special interest are photoactive semiconductors being used as photoanodes. Employing concepts of nanostructuring and doping combined with liquid phase technologies for constructing favorable layered configurations, metal oxides offer strategic advantages when it comes towards the use of abundant non-critical materials and sustainable fabrication of efficient large-area photoanodes. Deeper comprehension of the underlying photoelectrochemical processes provides the necessary feedback to a successful progress. In this presentation, boron-doped nanostructured TiO2 film electrodes are used as photoanode. We show that its photoelectrochemical performance can be successfully described by mathematical and physical models. This finding is of wider general interest to understand and improve the performance of nanostructured layered photoanode architectures.