Facile electrochemical synthesis of anatase nano-architectured titanium dioxide films with reversible superhydrophilic behavior

Abstract

In the present work we report a facile and readily-scalable electrochemical anodization technique for preparation of superhydrophilic TiO2 films having reversible wettability properties. The electrochemically anodized Titanium (Ti) foils manifest nanoscale topographical features, interconnected nanowebs and nanofibrils, that enhance both surface roughness and light absorption. After 5 min of UV illumination a water contact angle (WCA) of 4.8° is measured for a 5 μL deionized water droplet, while after 5 min of whitelight illumination the WCA is 3.2°. Moreover, under UV illumination the superhydrophilic Ti foils exhibit self-cleaning properties. Key factors contributing to the superhydrophilic character include surface topology, and surface chemical reactions.