Fabrication of titanium dioxide with durable superhydrophilicity by anodization

Abstract

Titanium-based materials with specific wettability show promising potential applications. In this paper, a titanium plate with hydrophilicity was simply synthesized by anodization with an electrolyte composed of NaOH, and their durability of wettability in the air was evaluated. The properties of the anodized Ti plate were characterized by a series of tests including FESEM, roughness, BET surface area, XRD, XPS, water contact angle, UV-vis absorption, photoluminescence, photocatalytic decomposition ability of methylene blue, self-cleaning property and durability of wettability in the air. When the processing time of the anodization was 10 minutes, the resulting titanium plate had a water contact angle of 0°, which proved that it was superhydrophilic, and it possessed a micro-nano composite architecture with a distinct nanofiber network chemically constituted of anatase and sodium titanate. It also exhibited excellent photocatalytic properties under UV illumination, including high photocatalytic activity and photocatalytic decomposition ability, as well as good self-cleaning properties, all of which rendered it to have good durability of wettability. Significantly, it can maintain the superhydrophilicity for 6 months in air. It is proposed that it is a synergy effect originating from the topology, chemical constitution and excellent photocatalytic properties that leads to the durable superhydrophilicity.