One-pot synthesis of nitrogen-doped TiO2nanorods with anatase/brookite structures and enhanced photocatalytic activity

Abstract

Nitrogen doping in combination with a heterostructure can not only modify the band structure of TiO₂ to make it more responsive to visible light, but also suppress charge recombination and lead TiO₂ to have enhanced photocatalytic activity as compared to P25. Also, one-dimensional TiO₂ nanostructures can serve as electron highways for efficient charge separation and, hence, increase the lifetime of charge carriers and enhance the efficiency of interfacial charge transfer to the adsorbed substrate. In this paper, a simple one-pot synthetic strategy has been designed for preparing TiO₂ nanorods with good crystallinity, nitrogen doping and anatase/brookite binary structure characters, using N₂H₄·H₂O as an in situ nitrogen doping source. The physicochemical properties of the catalysts can be tuned by simply changing the concentration ratios of N₂H₄·H₂O to TiO₂ colloids. The synergistic effect of nitrogen doping in association with a one-dimensional and anatase/brookite binary structure is suggested to account for the higher catalytic activity of the TiO₂ nanorods for decomposing methyl orange and 4-chlorophenol compared to the nanoparticle counterparts under UV and/or visible light illumination.