High photocatalytic activity of TiO2/Al2TiO5 coatings obtained by plasma electrolytic oxidation of titanium

In this work, it was shown that TiO2/Al2TiO5 coatings obtained by plasma electrolytic oxidation of titanium in alkaline electrolyte with added NaAlO2 show significantly better photocatalytic activity (PA) in degradation of methyl orange under simulated sunlight than anatase TiO2 coatings obtained in pure alkaline electrolyte. The TiO2/Al2TiO5 coating with the highest PA was obtained in alkaline electrolyte with the addition of 2.0 g/L NaAlO2, which has approximately 2.4 higher PA than anatase TiO2. Photoluminescence indicates that increased PA of TiO2/Al2TiO5 coatings is associated with increased number of oxygen vacancy and other defects.