One-step synthesis of ultrathin nanobelts-assembled urchin-like anatase TiO ₂ nanostructures for highly efficient photocatalysis

Nanostructured TiO2 materials with a controlled morphology and structure have drawn considerable attention to both fundamental research and practical applications owing to their unique characteristics. Herein, a novel, facile, and one-step hydrothermal approach was developed to synthesize urchin-like anatase TiO2 hierarchical nanostructures assembled from ultrathin nanobelts using urea as the morphology-directing agent. The effects of the urea concentration in the preparation process were discussed intensively. Photocatalytic experiments showed that the urchin-like anatase TiO2 nanostructures possessed a much higher degradation rate of methyl orange and phenol than the most successful commercial semiconductor photocatalyst P25. The reasons for the highly efficient photocatalytic activity was ascribed to the high specific surface area (171 m2 g−1) and ultrathin 1D nanobelts of anatase TiO2 self-assembled into the urchin-like hollow spheres. The urchin-like anatase TiO2 nanostructures as photocatalysts have potential applications in environmental and energy fields for photocatalytic degradation, hydrogen production, Li-ion batteries, and dye-sensitized solar cells. In addition, new hydrothermal method can be developed for synthesis of other hierarchical nanostructures.