Influence of oxidation process on photocatalytic activity of photocatalyst coatings by mechanical coating technique

• Published in: Materials science in semiconductor processing Vol. 30; pp. 128 - 134
• Main Authors: Lu, Yun, Kobayashi, Kouta, Guan, Sujun, Hao, Liang, Yoshida, Hiroyuki, Asanuma, Hiroshi, Chen, Jinxiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2015
• Subjects: Aluminum oxide; Anatase; Coatings; Composite coatings; Heat oxidation; Mechanical coating technique; Oxidation; Photocatalysis; Photocatalytic activity; Semiconductors; TiO2; Titanium; Titanium dioxide; Photocatalytic activity; Heat oxidation; Composite coatings; Mechanical coating technique; TiO2
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2014.10.004

Titanium (Ti) coatings on alumina (Al2O3) balls fabricated by mechanical coating technique (MCT) were oxidized in air at a series of relatively low temperatures with the oxidation time of 3h and 50h. Crystal structure and microstructure of the coatings were investigated. Photocatalytic activity of the coatings was evaluated and discussed. The results showed that titanium dioxide (TiO2) films on Ti or Ti/TiO2 coatings were fabricated by the MCT and subsequent heat oxidation. The oxidized coatings started to show the mixed-phase of anatase and rutile, at the temperature of 873K for 3h and 773K for 50h. With extending the oxidation time from 3h to 50h, the oxidative effect of relatively lower temperatures of 773K to 973K almost reached to that of higher temperatures, which is similar to the time–temperature equivalence principle. Photocatalytic activity of anatase TiO2 at 673K is higher than that of mixed-phase or rutile TiO2 under UV irradiation.