Probing the photoelectrochemical properties of hematite (α-Fe_2O_3) electrodes using hydrogen peroxide as a hole scavenger

摘要

We study hematite (α-Fe_2O_3) photoelectrodes for water splitting by examining the fate of photogenerated holes. Using H_2O_2 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 V_(rhb), electrolyte oxidation kinetics limits the performance but above 1.2 V_(RHe) bulk recombination becomes the limiting factor.