Hierarchical mesoporous anatase TiO₂ nanostructures with efficient photocatalytic and photovoltaic performances

Mesoporous anatase TiO₂ nanostructures with diverse morphologies ranging from rod-like 1D nanostructures to diverse hedgehog-like 3D hierarchical nanostructures have been found to display highly efficient photocatalytic and photovoltaic performances. Hierarchical 3D nanostructures exhibit 5.5 times higher photocatalytic activity than rod-like 1D nanostructures, and the DSSC efficiency of hierarchical 3D nanostructures becomes as high as 5.37%, which is 50% higher than the DSSC efficiency of 1D nanostructures. The high photocatalytic performances of the hierarchical 3D anatase TiO₂ nanostructures have been attributed mainly to their large specific pore volume, whereas the high photovoltaic performances of hierarchical 3D nanostructures have been attributed not only to their high specific surface area and the large specific pore volume but also to their interparticular connectivity. Comparative experimental studies have shown that the as-prepared hierarchical mesoporous anatase TiO₂ nanostructures show superior photocatalytic (three times higher) and photovoltaic performances (35% higher) to commercially available Degussa P25 TiO₂.