The Novel Application of N-Doped Tio2 Nanoparticles for Degradation of Chlorinated Herbicide Under Commercial Visible Led
N-doped TiO2nanoparticles were employed for degradation of 4-chlorophenoxyacetic acid under commercial visible light emitting diode(Visible LED) as a new illumination source in photocatalysis applications.The synergistic effect of N-doped TiO2/Visible LED hybrid process was systematically investigated by exploring the influence of several reaction parameters such as N-doped TiO2loading, the initial concentration of probe compound, initial solution pH, and inorganic anions.In addition, the mineralization capability of N-doped TiO2/Visible LED process was investigated. It was found that this process is capable of achieving 73% mineralization of probe compound and its intermediates. Moreover, the reusability mechanism of the N-doped TiO2 based on this process wasdiscussed in detail. Surprisingly, the degradation rate of 4-chlorophenoxyacetic acid increased after successive usage of the recycled catalyst. The mechanism of N-doped TiO2reusability was verified by XPS and FT-IR analyses. It was found that the incorporation of hydroxyl groups into the surface of N-doped TiO2 after each reuse is the rationale reason for the rate enhancement. These hydroxyl groups can provoke the formation of hydrogen bonding between the N-doped TiO2 andthecarboxyl group of 4-chlorophenoxyacetic acid, thereby accelerating the decay rate.This work may provide some useful and interesting information to the community of photocatalytic research, which may be helpful for applying this process for degradation of various herbicides under such kind of commercial visible LED lamps.