UV light photocatalytic degradation of organic dyes with Fe-doped ZnO nanoparticles

Abstract

Iron doped wurtzite ZnO nanoparticles were synthesized and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, UV–Vis diffuse reflectance spectroscopy, electron spin resonance and vibrating sample magnetometer techniques. The photocatalytic activities were also evaluated for the degradation of methyl orange and methylene blue under UV irradiation. The effects of various parameters, such as pH, dopant concentrations and photocatalytic dosage, were studied. The ESR results indicate the presence of Fe in both the Fe2+ and Fe3+ valence states. As the dopant concentrations increased, the number of spins due to Fe2+ ions increased and the number of spins due to Fe3+ ions decreased resulting in an increase in magnetization. The catalysts with the highest number of spins due to Fe2+ ions exhibited the optimum photocatalytic activity for the degradation of methyl orange and methylene blue. In addition, the role of photoactive species was investigated using a radical scavenger technique. The results indicated that the doping concentration is the most important factor in photocatalytic performance.