Preparation of iron-nitrogen doped titanium dioxide nanoparticles and its application for photocatalytic degradation of phenol under UV and visible light

Phenol is one of the most persistent organic pollutants which is toxic for human and its degradability is slow in the environment. The purpose of this study was to evaluate the photocatalytic process efficiency of iron-nitrogen doped titanium dioxide nanoparticles immobilized on a glass bed in removal of phenol from the aqueous medium. This experimental study was carried out on a laboratory scale using a reactor equipped with five UV lamps (6 W). Moreover in order to investigate the effect of visible light, five xenon (6 W) lamps were used as a visible light source. Operating parameters including pH, nanoparticle dosage, source of light, and initial phenol concentration as a function of contact time were investigated. Material characterization was carried out by X-ray diffraction, scanning electron microscope, X-ray microanalysis, and Fourier-transform infrared spectroscopy. The results showed that optimal conditions for phenol degradation under UV light included pH = 5, catalyst dose = 2 g m(-2), initial concentration of phenol = 25 mg L-1, and contact time = 90 min. Phenol removal of 88% and COD removal of 65% were reached at the optimal condition. However, the efficiency for visible light was three times less than UV light.