One-pot synthesis of nitrogen-doped TiO2 nanorods 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.