EVALUATION OF THE PHOTOCATALYTIC ACTIVITY OF α-MoO3 DOPED WITH RARE EARTH ELEMENTS ( La , Y ) FOR THE REMOVAL OF METHYL RED DYE

Abstract

This study deals with the use of molybdenum trioxide doped with different quantities of lanthanum or yttrium as catalysts in the photocatalytic processes  for removing methyl red from aqueous solution. Crystalline structure, surface area, pore volume, and pore diameter, characteristics that may significantly affect the photocatalytic activity of materials, have been studied, during the addition of lanthanum or yttrium to MoO₃, using several advanced techniques such as X-ray diffraction, Raman spectrometry, and nitrogen absorption. Diffraction patterns did not show any changes in MoO₃ structure when the doping rate was smaller than 0.6. In doping rates, greater than 0.6, new diffraction peaks related to other compounds have been noticed only in the case of L_xMoO₃. The addition of lanthanum or yttrium has increased the surface area of prepared materials, which contribute to enhancing the photcatalytic activity where the degradation rate of methyl red has reached to about 60% in the case of  L_xMoO₃ and to 95% in the case of Y_xMoO₃.