Fabrication of TiO2 nanotubes by atomic layer deposition and their photocatalytic and photoelectrochemical applications

The formation of TiO2 nanotubes was conducted by atomic layer deposition (ALD) with tris-(8-hydroxyquinoline) gallium (GaQ3) nanowires as a template at different substrate temperatures, 50, 100, and 200 deg. C. TiO2 nanotubes were formed only at 50 and 100 deg. C. Although a higher growth rate at 50 deg. C was observed, nanotubes with better uniformity, conformality, and less residual chloride were obtained at 100 deg. C because of a different formation mechanism. A photocatalysis test of TiO2 nanotubes prepared by different cycle numbers at 100 0C was conducted. It showed that TiO2 nanotubes prepared by 400 cycles of ALD and treated at 700 deg. C for 1 h to form anatase phase had the best photocatalytic performance. Compared with P-25, the nanotubes showed higher photocatalytic degradation of rhodamine B and water splitting efficiency.