“…TiO2 nanotubes have active photo catalysis characteristic, good corrosion resistance, thermal stability and good operation stability as described by Mahajan V et al, (2008). TiO2 nanotubes can be made by various ways including hydro/solvothermal method (Kasuga T et al, 1998), template-assisted approach (carbon nanotube, alumina or monocrystal as the template), sol-gel method (Kasuga T et al, 1998), microwave irradiation (Zhao Q et al, 2009), and direct electrochemical anodization. The advantage of the hydro/solvothermal method is easy to operate.…”