PREPARATION AND CHARACTERIZATION OF SOL–GEL-DERIVED TiO2/ITO PHOTOELECTRODES

Abstract

In this work, nanocrystalline TiO 2/ ITO electrodes were prepared by sol–gel method starting from tetrabutyl orthotitanate ( Ti ( OBu n)4) reacted with hydrogen peroxide in the ice-water bath. The sol–gel derived TiO 2 films were characterized by XRD, SEM, BET, and UV/Vis absorption spectroscopic techniques. The preparation conditions, including the number of coats and calcination temperature, were also investigated. Furthermore, PEC cells were constructed for testing the activities of prepared TiO 2/ ITO photoelectrodes. The photo-currents for hydrogen production via the PEC reaction were measured under UV irradiation (λ max = 253.7 nm ). The experimental results showed that the sol–gel derived TiO 2 films calcined at 300°C–600°C were anatase structure and they showed a maximum UV/Vis absorption at about 380 nm. Moreover, from the result of PEC reactions, it was found that the TiO 2/ ITO photoelectrode (calcined at 600°C, with the thickness of TiO 2 layer of about ~0.2 μm) demonstrated a large saturation current (0.326 mA/cm2) with a quite high photoelectrochemical conversion efficiency of 2.39%.