Insight into the influence of high temperature annealing on the onset potential of Ti-doped hematite photoanodes for solar water splitting

The unfavorable onset potential shift of Ti:Fe2O3 photoanode induced by high temperature post-annealing was studied. The underlying mechanism is the surface Ti/Fe atomic ratio increase, leading to adsorption capacity change of surface hydroxide ions and the positive shift of flatband potential (i.e., theoretical onset potential).