Facile synthesis of flowery N-doped titanates with enhanced adsorption and photocatalytic performances

Abstract

Novel flowery N-doped titanate photocatalysts were synthesized using titanium nitride (TiN) as the precursor. It is found that N-doped titanates with flowery nanostructures can be directly obtained through a one-pot hydrothermal process in an alkali solution. The specific surface area reaches 178.8 and 215.3 m² g⁻¹ for the N-doped titanates prepared in 5 M NaOH and 10 M NaOH, respectively. X-ray photoelectron spectroscopy results demonstrate that nitrogen is doped into the lattice of the titanates. A red shift of the optical absorption edge is observed for the resulting samples in comparison to that of P25 TiO₂. Excellent adsorption capability for methylene blue (MB) and good photocatalytic performance for MB degradation under ultraviolet light irradiation are demonstrated for the samples. It is shown that the adsorption behavior of the titanates is comparable to that of activated carbon. Moreover, the sample prepared in 5 M NaOH shows a higher photocatalytic activity than that of P25 TiO₂. The outstanding adsorption property and good photocatalytic performance can be ascribed to the high specific surface area, three dimensional nanostructure and substitutional nitrogen doping. This work provides a facile strategy for the preparation of titanates with excellent adsorption behavior and good photocatalytic activity, showing potential applications in water treatment and environmental protection.