Photocatalytic activity of bipolar pulsed magnetron sputter deposited TiO2/TiWOx thin films

• TiO2/TiWOx films were fabricated by a bipolar pulsed magnetron sputtering apparatus.
• Titanium oxide being sputtered tungsten enhanced the highly oriented of TiO2 (1 0 1) plane of the specimen assemblies.
• The mechanism WO3(h+, e−)/TiO2(h+, e−) → WO3(e−)/TiO2(h+) shows the higher hydrophilicity and lower contact angle.

Titanium oxide films were formed by sputtering and then TiWOx films were deposited by bipolar pulsed magnetron sputtering with pure titanium and tungsten metal targets. The sputtering of titanium oxide with tungsten enhanced the orientation of the TiO2 (1 0 1) plane of the specimen assemblies. The main varying parameter was the tungsten pulse power. Titanium oxide sputtered with tungsten using a pulsing power of 50 W exhibited a superior hydrophilic property, and a contact angle of 13.1°. This fabrication conditions maximized the photocatalytic decomposition of methylene blue solution. The mechanism by which the titanium oxide was sputtered with tungsten involves the photogeneration of holes and electron traps, inhibiting the hole–electron recombination, enhancing hydrophilicity and reducing the contact angle.