Au or Ag nanoparticle-decorated 3D urchin-like TiO₂ nanostructures: Synthesis, characterization, and enhanced photocatalytic activity

The semiconductors decorated with noble metals have attracted increasing attention due to their interesting physical and chemical properties. Here, 3D urchin-like hierarchical TiO₂ nanostructures decorated with Au or Ag nanoparticles were prepared by wet-chemical process. The morphology and structure were characterized by different techniques. It shows that Au or Ag nanoparticles with narrow distribution are uniformly loaded on urchin-like TiO₂ nanostructures, and the resulted composite nanostructures show distinct surface plasmon absorption band and quenched photoluminence compared to pure TiO₂ nanostructures. Photocatalytic tests show both Au-decorated TiO₂ and Ag-decorated TiO₂ exhibit enhanced photocatalytic activity for photodegradation of methyl blue in water.