Synthesis and photocatlytic performance of nano-sized TiO₂ materials prepared by dealloying Ti-Cu-Pd amorphous alloys

TiO₂ nanospindles with exposed (0 0 1) facet were synthesized through a simple dealloying reaction. The rutile photocatalysts were characterized by X-ray diffraction, scanning electron microscope and transmission electron microscope, inductively coupled plasma optical emission spectrometry and ultraviolet-visible spectrophotometer. A Rhodamine B dye (RhB) was used to detect the photocatalytic activity of TiO₂ under full light irradiation. The presence of Pd in the original amorphous alloy reduced the surface free energy of TiO₂, stabilized the (0 0 1) facet. The Pd8-TiO₂ sample exhibited the largest crystal size along the direction which is perpendicular to the (0 0 1) facet. The photocatalytic degradation rate of RhB was improved due to the Pd addition in the original amorphous alloy. This indicated that the exposure of (0 0 1) facets could enhance the activity of TiO₂ photocatalyst. In addition, the presence of isolated Pd atoms on the surface of TiO₂ would be another probable reason for the improvement of photocatalytic activity.