Study on the Catalytic Activity of Cerium/Cadmuim Mixed Oxide Catalysts for the Photo catalytic Degradation of Orange G Dye

Abstract

The Mono and binary-mixed oxide catalysts were prepared by precipitation and co-precipitation method and investigated for the photocatalytic decolorization of orange G dye which was used as a pollutant model in this study. The structure of the synthesized catalysts were characterized by the X-ray diffraction (XRD), bonding by fourier transfer infrared (FTIR), morphology by scanning electron microscope (SEM) and reflection using UV-VIS diffuse reflectance spectra. The XRD results revealed that the mono oxide catalysts confirm well the cubic phase of cadmium and cerium oxide and that their mixed oxide catalyst i.e. 50Ce/25Cd  show the same characteristic peaks of pure cerium oxide with slight shift to higher wave lengths for two crystalline peaks at 33.15° and 56.15°  respectively.   The FTIR spectra of 50Ce/25Cd  mixed oxide catalyst improved the combination between both pure cadmium and cerium oxide catalyst. The diffuse reflectance showed a blue shift towards lower wave length and that the energy gap was increased with an increase in cerium content. Different  reaction  variables  such  as, effect of  metal content,  pH values,  amount  of  hydrogen  peroxide and effect of  catalyst amount were  studied  to estimate  their  effect  on  the  decolorization  efficiency  of  orange G dye.  The  maximum  catalytic activity achieved  was  91%  at  a  solution  pH  of  2.1,  catalyst  dosage  of  1.5  g/L,  0.15 mL of  H₂O₂ /100  mL of reaction volume  and  initial dye  concentration  of  10  mg/L after 60 min of reaction time.