We recorded strong enhancement of the photocurrent and lowering of the flat-band values for the Nitrogen-annealed photoanodes compared to air-annealed ones. It is important to mention that the absolute photocurrent values we determined are lower compared to cutting-edge ones reported for hematite-based photoanodes, even though not strictly in the same working conditions. Our work aims to compare strictly the PEC activity between two kinds of hematite-based photoanodes, air-and Nitrogenannealed, and to clarify the origin of the enhancement observed for the latter. For this purpose, we correlate macroscopic PEC (photo-voltammetry, EIS -Electrochemical Impedance Spectroscopy) and stateof-the-art synchrotron X-rays spectromicroscopy measurements (S-XPEEM -Shadow X-rays Photoemission Electron Microscopy, STXM -Scanning Transmission X-rays Microscopy, spectro-ptychography), completed by electron microscopy (STEM -Scanning Transmission Electron Microscopy). The results demonstrate the formation of surface pseudo-brookite clusters yielding partial Ti:Fe2O3/Fe2TiO5 interface. Our data suggest that this heterostructuring is at the origin of the better charge separation through the formation of corresponding surface states. Interestingly, we observe that a very low fraction (< 5 %) of the Ti-doped hematite is covered by pseudo-brookite clusters and thus responsible for the enhanced PEC activity.