Enhancing Photocatalytic Activity of Nitrogen Doped TiO2 for Degradation of 4-Chlorophenol under Solar Light Irradiation

The nitrogen doped TiO2 as a heterogeneous photocatalyst via sol-gel method was successfully synthesized. The as-synthesized photocatalysts were characterized with X-ray diffraction (XRD), surface area measurements (BET and BJH), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and energy dispersive X-ray spectrum (EDX). The activities of as-prepared TiO2 photocatalysts were examined to degrade 4-Chlorophenol aqueous solution under solar irradiation in a photoreactor; in addition, photocatalytic degradation mechanism and pathway were investigated. The results showed that 3 % wt N-doped TiO2 nanoparticles (under conditions of solution pH of 4.0, catalyst loading of 2 g/L, initial 4-CP concentration of 10 mg/L, and irradiation time of 8 h) exhibited much higher photocatalytic degradation efficiency (91 %) as compared with that of 5 % wt N-doped (83 %), 1 % wt N-doped (71 %), and pure TiO2 (35 %).