Sol-gel preparation and photoelectrochemical properties of Fe2TiO5 thin films

Polycrystalline Fe2TiO(5) films were prepared on nesa silica glass substrates by the sol-gel method, and their photoanodic properties were measured in a three-electrode wet cell with an aqueous buffer solution of pH = 7. Gel films were crystallized into Fe2TiO(5) when fired at greater than or equal to 500 degreesC. The photoanodic current significantly increased when the films were fired at 700 degreesC, and then decreased with increasing firing temperature. Thicker films obtained by repeating the gel film deposition and firing showed smaller photocurrent, and the 50 nm thick film prepared via non-repetitive deposition exhibited the maximum photocurrent. Although the photoresponse was extended to wavelengths near 500 nm, the maximum quantum yield was as low as 0.12 at a wavelength of 340 nm.