Photoelectrochemical Sensing of Hydrogen Peroxide on Hematite

Due to its abundance and chemical stability, hematite (alpha-Fe2O3) is a promising n-type semiconductor photoelectrode. This is particularly true in the frame of the rapidly developing area of photoelectrochemical (PEC) sensing, where the short excited-state lifetime and the small carrier diffusion length of hematite can be beneficially employed. On the other hand, H2O2 is an essential molecule for biological, environmental and industrial applications. In this article, we report a simple method to prepare photoelectroactive hematite layers on fluorine-doped SnO2 (FTO) and we use these surfaces for H2O2 PEC sensing. The so-created sensors allow to reliably detect H2O2 down to a sub-mu M concentration with a large linear range and a good reusability.