Highly crystalline and oriented Na2Ti3O7 whiskers were successfully and directly grown on a metallic titanium mesh using a NaCl flux cooling method for application to semiconducting photocatalysis. Specifically, unique three-dimensional photocatalytic materials were fabricated by converting a titanium mesh into a Na2Ti3O7 tubular mesh consisting of highly oriented whiskers. The formation mechanism of the oriented Na2Ti3O7 whiskers was investigated using field emission scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray diffraction. From these results, the following conclusions could be confirmed. First, a titanium oxide layer was formed on the Ti wire surface by thermal oxidation. Since this oxide layer acts as a protective layer to thermal energy, the wire shape was maintained during Na 2Ti3O7 whisker growth. Next, highly oriented Na2Ti3O7 whiskers were directly grown on the titanium oxide layer. During whisker growth, Ti was radially supplied from the bulk of the Ti mesh to the inner surface of the TiO2 layer. Finally, the Ti wire structure transitioned into a tubular structure consisting of Na2Ti3O7 whiskers. During the fabrication process, the Ti wire was dissolved by the NaCl flux, and the dissolved Ti ions reacted with O and Na ions to form TiO2 and Na2Ti 3O7 layers. As a result, oriented and highly crystalline Na2Ti3O7 whiskers were directly grown on the TiO2 layer. The Ti wire was completely dissolved in this reaction system. Furthermore, the photocatalytic activities of the tubular mesh consisting of Na2Ti3O7 whiskers were confirmed by the photocatalytic degradation of a fluoroalkylsilane self-assembled monolayer and trichloroethylene under ultraviolet light irradiation. The whisker mesh developed herein exhibited good photocatalytic properties under ultraviolet light irradiation.
All Science Journal Classification (ASJC) codes
- 化学 (全般)