Study on the Photo Catalytic Ability of Plasma Splayed TiO₂-HAP Compound Coatings

The photo catalytic TiO₂ coatings on biodegradable plastic (polybutylene succinate: PBS) were prepared by using plasma splaying techniques. It is reported that there is a possibility that the performance of photo catalytic TiO₂ coating may be advanced by addition of absorption ability [1]. It is also well known that the extraordinary absorption ability of HAP (hydroxyapatite) [2]. In this study, to investigate the influence of the addition of absorption ability to the coatings, not only pure anatase TiO₂ powder but also two types of TiO₂-HAP compound powder (TiO₂- 10wt.%HAP, TiO₂-30wt.%HAP) were used as thermal splay materials. The microstructure of coatings was characterized with SEM and XRD analysis, and some photo catalytic ability of coatings as a functional material was evaluated. One was the air purification performance of the coatings through the photo degradation of acetaldehyde gas, and the other was the sterilization performance to bacteria. In not only pure anatase TiO₂ powder condition, but also in TiO₂-10wt.%HAP and in TiO₂-30wt.%HAP powder condition, the high anatase ratio which was approximately 95% were verified. In terms of decomposition ability to acetaldehyde gas, TiO₂-10wt.%HAP coating was predominate to the others. This result indicates the addition of absorption ability. In terms of sterilization ability to bacteria and bacteria absorption, TiO₂-HAP compound powder coatings showed a good performance.