ENHANCEMENT OF THE PHOTOCATALYTIC PROPERTIES OF TITANIA NANOPARTICLES BY DOPING LANTHANIDE IONS

Document Type : Original Article

Authors

1 Department of Chemistry, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo, Egypt

2 Central Metallurgical R and D Institute, CMRDI, P.O. Box 87 Helwan, Cairo, Egypt

Abstract

Lanthanide ions  (La3+, Nd3+, Sm3+, Eu3+, Gd3+, and Yb3+)- doped TiO2 nanoparticles were successfully synthesized by sol-gel method to enhance the photocatalytic activity of the developed materials. The structural features of TiO2 and lanthanide ions–doped TiO2 fired at 550ºC were investigated by XRD, UV-diffuse reflectance, and nitrogen adsorption measurements. The effect of lanthanide ions-doped TiO2 on the photoactivity was evaluated by the degradation of direct blue dye (DB 53) as a probe reaction. Our findings indicated that XRD data verified the formation of typical characteristic anatase reflections without any separate dopant-related peaks in all the prepared lanthanide ion-doped TiO2 nanoparticles. The particle size of lanthanide ions-doped TiO2 nanoparticles was smaller than pure TiO2 indicating the improvement of its surface morphology. The results indicated that Gd3+-TiO2 has the lowest bandgap and particle size and the highest surface area and pore volume (Vp) as well. The photocatalytic behavior of lanthanide ions-doped TiO2 was tested for oxidation of DB 53 in the presence of UV light at λ = 365 nm. It was found that Gd3+-TiO2 is the most effective catalyst in the photocatalytic activity studies. That might be due to its special characteristics of particle size, surface texture and bandgap properties. Our results should provide a significant contribution to the understanding of the chemistry of lanthanide iondoped TiO2 systems. Details of the synthesis procedure and results of the characterization studies of the produced lanthanide ions-TiO2 are presented in this paper.

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