Activation of Oxone® with plasma deposited mixed cobalt and alumina oxide for the dye degradation.

• Co2+ doped Al 2 O 3 coatings were formed by plasma electrolytic oxidation (PEO). • Cobalt content of coatings increased in agreement with Co2+ content of PEO solutions. • Cobalt in coatings significantly improved catalytic activity in the Oxone® based AOP. • The Co2+ doped Al 2 O 3 coatings exhibited good stability in the investigated reaction. The aim of this work is to examine the possibility of the formation of cobalt doped Al 2 O 3 coatings on aluminum substrate by plasma electrolytic oxidation process (PEO) and application of the obtained material as catalyst in the sulfate radical (SO 4 −) based advanced oxidation process (SR-AOP). The morphology and elemental composition, of the coatings were characterized using Scanning Electron Microscopy. The obtained material was tested as catalyst in SR-AOP in the degradation of model dye (tartrazine) in aqueous solution. Potassium peroxymonosulfate (Oxone®) was used as the source of radicals. The catalytic role of cobalt in tartrazine decolorization was tested in the catalytic system consisting of PEO cobalt doped Al 2 O 3 coated Al plates and Oxone®. It was found that the addition of cobalt precursor into PEO electrolyte solution significantly improved the catalytic properties of obtained coatings with respect to cobalt-free Al 2 O 3 coating and Oxone®. The influence of cobalt content in the supporting electrolyte during PEO process on the catalytic activity of the coatings, as well as Oxone® dosages in SR-AOP, were examined. [ABSTRACT FROM AUTHOR]