Hematite(α-Fe2O3)semiconductor has long been used as an active photoanode for photoelectrochemical(PEC)water oxidation reaction.1 In this work,highly active Fe2O3 electrodes were fabricated by a hydrothermal method on the FTO substrate followed by a high-temperature heat treatment.2 The electrodes were characterized before and after the heat treatment process by scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray diffraction(XRD).It was demonstrated that the product of the hydrothermal process was P-FeOOH,and it was converted to α-Fe2O3 by the heat treatment,2,3 The temperature of the heat treatment process was found to play an important role in the photoactivity of the final product.The higher the temperature,the more complete the transformation was conducted,however,the square resistance of the FTO substrate would drastically rise if the temperature increased to a certain degree.