Effect of Ti pretreatment on photoelectric properties of TiO2 layers prepared by plasma-anodic oxidation

Photoactive TiO2 layers were formed by anodic oxidation of Ti in O2 RF plasma under various conditions and applying various Ti surface pretreatment procedures. The photocurrent spectrum in 1M NaOH was used to calculate the quantum efficiency of the photocurrent production and the band-gap energy for indirect transitions. The photoelectrochemical properties of TiO2 layers were studied on the decomposition of an aqueous solution of p-cresol. The method of Ti surface pretreatment (mechanical polishing and electrochemical etching) has a decisive effect on the photoelectrochemical properties and the structure of the polycrystalline oxide, rutile, anatase, or the amorphous phase content. (author) 6 figs., 12 refs