Catalyst-free synthesis, morphology evaluation and photocatalytic properties of pristine and calcinated titanate nanorods

Titanate nanorods with high photocatalytic activity was successfully synthesized through a simple catalyst-free hydrothermal method. The photocatalytic degradation of a model organic dye (Reactive Red 198) was accelerated by the calcination of the nanorods prior the reaction. The calcination of nanorods did not modify their morphology, however the crystallinity of the samples was significantly improved. Therefore, the quality of the samples is a key parameter determining their activity in the investigated photocatalytic process. The as-produced and annealed catalysts were characterized by high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Diffuse Reflectance (DR) UV–Vis and resonance Raman spectroscopy.

Research highlights
► In the present work, titanate nanorods with the large interlayer spacing of 0.96 nm were successfully synthesized via hydrothermal treatment of TiO2-P25 in 10 M NaOH solution at higher than previously reported temperature (that is 210 °C).
► The calcination of this material does not leads to the significant morphology modifications.
► However the photocatalytic activity is enhanced upon the thermal treatment.