Formation of a photocatalytic WO₃ surface layer on electrodeposited Al-W alloy coatings by selective dissolution and heat treatment.

ABSTRACT: In this study, we explored the feasibility of WO₃ surface layer formation on electrodeposited Al-W alloy coatings by selective dissolution and heat treatment, with the aim of providing corrosion-resistant Al-W alloy coatings with photocatalytic self-cleaning properties under visible light illumination. The selective dissolution of Al and oxidation of residual W was carried out by immersing Al-W alloy films in an aqueous solution of nitric acid. A nanostructured H₂WO₄·H₂O surface layer was formed on the alloy film by this process. The H₂WO₄·H₂O layer was dehydrated to WO₃ by heat treatment, yielding a multilayered WO₃/Al-W alloy film with an approximately 300?nm thick WO₃ layer. The WO₃/Al-W alloy film exhibited photocatalytic self-cleaning, as demonstrated by the photodegradation of stearic acid and methylene blue. We also confirmed that selective dissolution and heat treatment did not significantly diminish the corrosion resistance of the Al-W alloy films.

SUBMITTER: Higashino S 

PROVIDER: S-EPMC6831697 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature