Probing the photoelectrochemical properties of hematite (α-Fe2O3) electrodes using hydrogen peroxide as a hole scavenger

We study hematite (α-Fe2O3) photoelectrodes for water splitting by examining the fate of photogenerated holes. Using H2O2 as an efficient hole scavenger, we collect all holes that arrive at the electrode/electrolyte interface. This provides the ability to distinguish between and quantify bulk and surface recombination processes involved in the photoelectrochemical oxidation of water. Below 1.0 VRHE, electrolyte oxidation kinetics limits the performance but above 1.2 VRHE bulk recombination becomes the limiting factor.