Photocurrent Properties of TiO2 Nanorods Grown on FTO by Hydrothermal Method

Abstract

In this work, we undertake a comparative study of the crystallographic microstructures and photo-catalytic properties of rutile TiO2 nanorods grown on FTO facing up and down by a hydrothermal method. An analysis of the fine structures showed that TiO2 nanorods grown on FTO facing up were mixed with sea urchin and microsphere. These structures induced a vertical orientation of the nanorods on FTO. The saturated photocurrent densities of the TiO2 nanorods grown both up and down were 1.5 mA/cm(2) in the former case, the IPCE was increased to 10% at 300 similar to 350 nm. The onset potential (?flat band potential) of the nanorods grown on FTO facing up is negatively shifted to a value of -0.31 V. This is caused by an increase in the surface state, in this case the number of oxygen vacancies, and by the formation of Ti3+. Therefore, the FTO facing direction is considered as a critical factor during the hydrothermal reaction for TiO2 growth so as to develop an efficient photo-catalytic system.