Light-Driven Preparation, Microstructure, and Visible-Light Photocatalytic Property of Porous Carbon-Doped TiO_2

摘要

Highly porous carbon-doped TiO_2 (C-TiO_2) has been prepared, for the first time, through a light-driven approach using crystalline titanium glycolate (TG) as the single-source precursor. Although the nonthermally prepared porous C-TiO_2 is amorphous, it shows a remarkable visible-light photocatalytic activity higher than that of nitrogen-doped TiO_2 (N-TiO_2) due to its significant surface area (530 m~2/g) and pore-rich structure. X-ray photoelectron, electron paramagnetic resonance, and UV-Vis diffuse reflectance spectroscopy reveal that the as-prepared porous C-TiO_2 photocatalyst contains Ti-O-C bonds which result in visible-light absorption of the material at wavelengths less than 550 nm. Furthermore, it is discovered that the Ti-O-C bonds in the as-prepared C-TiO_2 is easily transformed to coke-type species under mild thermal treatment (200℃). The resulting coke-containing porous TiO_2 is an even better visible-light photocatalyst, almost twice as effective as N-TiO_2, because of its stronger visible-light absorption. The Ti-O-C and the coke-containing porous TiO_2 materials follow two different mechanisms in the visible-light photocatalysis process for degradation of methylene blue.