A novel ammonia complex-assisted ion-exchange strategy to fabricate heterostructured PdO/TiO nanorods with enhanced photocatalytic activities

Heterojunctions have been often employed to improve the photocatalytic behavior of titania-based materials. Herein, we propose a novel strategy to fabricate PdO/TiO heterostructured nanorods, as PdO was proved to be an efficient co-catalyst in photocatalytic reactions. Primarily, ammonia complex-assisted ion-exchange method was used to store Pd(II) ions in protonated titanate nanotubes, as which cannot be replaced by metallic cations via traditional route. Then, PdO/TiO heterojunctions formed through calcination in air, as nanotubes dehydrated and shrank into nanorods. X-ray diffraction, Raman spectra, and X-ray photoelectron spectroscopy were used to demonstrate the formation of PdO component, and transmission electron microscopy was employed to prove the successful connection between TiO nanorods and PdO nanoparticles. Moreover, inductive coupled plasma proved excellent compositional gradient of Pd(II) in the PdO/TiO heterostructured nanorods. In the present work, the photocatalytic activities of PdO/TiO heterostructured nanorods were investigated by decoloring several dyes under UV illumination. Our research revealed appropriate PdO loading (1.0 wt%) enhanced photocatalytic performance compared with bare TiO nanorods, where PdO/TiO heterojunctions were responsible for the prohibitive photogenerated carries recombination. [Figure not available: see fulltext.]