n-Type TiO[sub 2] Thin Films for Electrochemical Ozone Production

Abstract

An electrode for the electrochemical production of ozone, which has the compositional sequence ( is titanium oxide), was fabricated by sputtering thin film (the thickness is typically 300 nm) on a substrate. The thin film was characterized by X-ray diffraction, transmission electron microscopy, UV photoelectron spectroscopy, UV-visible spectroscopy, and photoelectrochemical measurements: It is an n-type semiconductor of the rutile-type . The electrochemical ozone production (EOP) was realized, and a high current efficiency of 9% was achieved at a low current density of in 0.01 M at . The observed high efficiency of EOP was considered to originate from the electrocatalysis of the n-type in the dark when a large anodic bias was applied in which, based on the band structure of the n-type solution interface, electron tunneling can take place through a deep depletion layer of the surface.