Formation of microarc oxidation coatings on magnesium alloy with photocatalytic performance

► TiO2 nanoparticles of electrolyte affect the MAO coatings significantly. ► TiO2 nanoparticles change the MAO coating from gray to blue. ► The blue MAO coating contains anatase TiO2 and rutile TiO2. ► The blue MAO coating performs certain photocatalytic performance.