Architecture, optical absorption, and photocurrent response of TiO 2-SrTiO3 and TiO2-CeO2 nanostructured composites
Journal
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
8793
ISBN
9780819496300
Date Issued
2013
Author(s)
Abstract
This study investigates the microstructure, optical absorption and photoelectric properties of nanostructured composites of TiO2 nanotube arrays and SrTiO3 or CeO2 nanoparticles. The composites were fabricated by anodization and hydrothermal methods and their UV-visible and ultraviolet photoelectron spectra (UV-Vis and UPS) were measured to determine the band structures of the TiO2-SrTiO3 and TiO2-CeO2 heterojunctions. The heterojunctions are designed to promote the separation of photo-induced electron and hole (e-/h+) pairs when the nanostructured composites are adopted in photocatalytic or photoelectrode applications. Approximately 1.0 and 0.8 eV shifts in conduction band position were determined for the TiO2-SrTiO3 and TiO2-CeO2 heterojunctions, respectively. The photocurrent densities of the TiO2- SrTiO3 and TiO2-CeO2 composites were about 20 to 40% larger than that of the TiO2 nanotube arrays under identical irradiation conditions. The size of the SrTiO3 and CeO2 nanoparticles, which could be controlled by the hydrothermal temperature and time, and the concentration of oxygen vacancies within the TiO2 nanotubes were identified to be the key factors governing the photocurrent densities of the nanostructured composites.
Type
conference paper