Inner Layer Control of Performance in a Dye-Sensitized Photoelectrosynthesis Cell.

Interfacial charge transfer and core-shell structures play important roles in dye-sensitized photoelectrosynthesis cells (DSPEC) for water splitting into H2 and O2. An important element in the design of the photoanode in these devices is a core/shell structure which controls local electron transfer dynamics. Here, we introduce a new element, an internal layer of Al2O3 lying between the Sb:SnO2/TiO2 layers in a core/shell electrode which can improve photocurrents by up to 300%. In these structures, the results of photocurrent, transient absorption, and linear scan voltammetry measurements point to an important role for the Al2O3 layer in controlling internal electron transfer within the core/shell structure.