Enhancing the Photocatalytic Activity of Nano Nd-TiO2@SiO2 by coupled systems

Metal doped TiO2 catalysts were synthesized by sol-gel method and their activities were determined for degradation of methyl orang as a pollutant. Nd-doped TiO2 showed the maximum activity comparing with others. Colloidal SiO2 was used as a support to increase the surface area and also the activity. Nano-TiO2/SiO2/Nd was synthesized by sol-gel method and it was characterized using XRD, XRF, SEM, TEM and BET methods. The major phase of synthesized catalyst was anatase and the crystal size estimated about 30 nm which was confirmed by TEM. BET analysis showed that deposition of catalyst on colloidal silica, enhanced the surface area significantly. It was found that the solution pH has great effect on kinetic and efficiency of the degradation process. At low pHs the degradation rate was faster comparing with alkaline solutions. Applying various fields to enhance the kinetic and efficiency of the photochemical process was studied. It was found that electric field (EP) has the most significant effect. Ultrasonic (UP) and magnetic (MP) fields were also effective in some cases. LC MS analysis showed that mineralization could be completed at the end of process.