Preparation and bioactivity of TiO2 nanotube arrays containing calcium and phosphorus

► TiO2 nanotube containing Ca and P were prepared through anodization and hydrothermal treatment. ► The tubular anatase nanotubes were transferred into four pillars after hydrothermal treatment. ► Apatite forming ability of TiO2 nanotube after hydrothermal treatment in Ca(OH)2 are excellent.