M Babaei - School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran
C Dehghanian - School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran

Plasma electrolytic oxidation technique was employed to grow zirconia–titania layers on titanium substrate.The top layer surface revealed a porous structure with nano formations of less than 100 nm in size. Considering the chemical and the electrochemical foundations, a probable formation mechanism was put forward. The photocatalytic performance of the composite layers was significantly higher than that of the pure titania layers.

Plasma electrolytic oxidation; titanium oxide; zirconium oxide; porous