Annealing effect on the microstructure and electrochemical properties of Fe2O3/H-TiNT/FTO thin film.

A layer of titanate nanotubular (H-TiNT) particles between Fe2O3 film and FTO substrate was inserted and heat-treated to improve electrochemical property of Fe2O3 for water splitting. Heat-treatment of the synthesized F2O3/H-TiNT/FTO thin film was found to significantly affect photoelectrochemical properties of the film through electrochemical impedance analysis. The film showed larger oxidation-reduction peaks of I-V characteristics and capacitive properties under UV-Vis light illumination with heat treatment temperatures during transformation of H-TiNT into anatase TiO2 phase. The overall results showed an appropriate heat treatment was a promising way to improve the electrochemical property of the photoanode film.