Spiky niobium oxide nanoparticles through hydrothermal synthesis

The development of ceramic nanomaterials with unique structure is necessary for discovery of novel property. We developed a novel niobium oxide nanoparticles with a spiky morphology. The spiky structure was composed of two kinds of component: niobium oxide hydrate sphere core and niobium pentoxide nanorods. These spiky niobium oxide nanoparticles are easily synthesized by hydrothermal treatment of niobium oxalate solution at 200 °C for 2 h, and their particle size could be tuned from 80 to 300 nm with 5–10 nm of nanorod on the surface by adjusting niobium concentration in the niobium oxalate solution. The band gap energy of the spiky nanoparticles was around 3.4 eV, and the spiky niobium oxide nanoparticles showed a light absorption in a wide wave length range from 380 to 700 nm. The niobium oxide nanoparticles are applicable as both solid acid catalyst and photocatalyst because of their spiky and two-layer structure.