Self-organized amorphous TiO2 nanotube arrays on porous Ti foam for rechargeable lithium and sodium ion batteries

► Self-organized amorphous TiO2 NTAs have been successfully fabricated on Ti foam. ► TiO2 NTAs on Ti foam were used as anodes in Li and Na-ion batteries. ► TiO2 NTAs on Ti foam exhibited improved cycling performance than on Ti foil. ► Self-improving of the specific capacity of Na-ion half cell was occurred during cycling.