The practical application of powder photocatalysts for visible light catalysis can be limited due to the accumulation of nanoparticles and the complexity of their recovery. Therefore, photocatalytic coatings are suitable candidates for pollutant degradation. In this study, a hierarchical TiO2/WO3 hybrid coating was created on a Ti substrate using plasma electrolytic oxidation (PEO) followed by hydrothermal treatment as a post-treatment
