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.

Preparation of hydrogen titanate nanotube/FTO glass thin film obtained by the layer-by-layer-self assembling method for water splitting.

Hydrogen titanate nanotube (H-TiNT) particles were coated porously on a fluorine-doped tin oxide glass using the layer-by-layer self assembling method and then heat-treated at temperatures below 600 degrees C for 10 min in air. The microstructure, crystallinity, and optical absorbance of the heat-treated H-TiNT thin film were investigated using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and UV-vis spectroscopy, respectively. Also, I-V characteristics of the fibrous H-TiNT particles in the thin film using linear cycle voltammetry under ultraviolet-A irradiation were analyzed to have a maximum current value at applied voltages with the increase in heating temperature for economic water splitting.

Crystalline characterization and photodecomposition properties of rod-shaped Na2Ti6O13 powder prepared by molten salt process.

To prepare one-dimensional nanostructured Na2Ti6O13 powder, the starting materials of TiO2, NaCl and Na2CO3 were mixed and then heat-treated at 1000 degrees C for 2 hrs in air under molten state of NaCl. Changes in shape and phase, photo absorbance and photocatalytic ability of TiO2 particle were observed controlling added amount of Na2CO3 under constant weight ratio of TiO2 to NaCl using SEM, X-ray diffractometer, Raman spectroscopy, and UV-Vis spectroscopy. The TiO2 particle was changed into rod-shape Na2Ti6O13 with the addition of Na2CO3, showing increase in optical energy band-gap of the powder as well as gradual decrease of the photo-decomposition ability.