New hierarchical titania-based structures for photocatalysis

A new preparation method of bulk hierarchic titania structures for photocatalysis is proposed. A highly porous metallic Ti preform was converted into TiO₂ for the first time using a combination of an oxidative construction of thin-wall ceramics (OCTWC) method, intermediate transformation into sodium titanate by hydrothermal treatment in alkaline aqueous solutions and shape preserving removal of sodium by a secondary hydrothermal treatment in acidic aqueous solution yielding a material of rutile/anatase titania with highly developed surface and high photocatalytic activity.