Development of Photocatalytically Active Anodized Layers by a Modified Phosphoric Acid Anodizing Process for Air Purification.

Autor: Lederer, Stephan, Benfer, Sigrid, Bloh, Jonathan, Javed, Rezan, Pashkova, Aneta, Fuerbeth, Wolfram
Předmět:
Zdroj: Corrosion & Materials Degradation; Mar2023, Vol. 4 Issue 1, p18-30, 13p
Abstrakt: One of the key urban air quality issues is pollution by nitrogen oxides (NO x ). To reduce NO x , facade cladding could be provided with photocatalytic properties by incorporating titanium dioxide nanoparticles. For this purpose, a modified phosphoric acid anodizing process (MPAA) was developed for the facade alloy EN AW-5005, in which highly ordered anodized structures with a low degree of arborization and tortuosity were produced. Pore widths between 70 nm and 150 nm and layer thicknesses of about 2–3 μ m were obtained. The subsequent impregnation was carried out by dip coating from water-based systems. Depending on the dip-coating parameters and the suspension used, the pores can be filled up to 60% with the TiO 2 nanoparticles. Photocatalytic tests according to ISO 22197-1 certify a high photocatalytic activity was obtained with rPCE values > 8 and with rPCE > 2, achieving "photocatalytically active for air purification". Tests on the corrosion resistance of the anodized coatings with a commercially available aluminum and facade cleaner confirm a protective effect of the anodized coatings when compared with nonanodized aluminum material, as well as with compacted anodized layers. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index