Enhanced Catalytic Degradation Of AO7 In The CeO₂-H₂O₂ System With Fe³⁺ Doping

A series of Fe3+ doped CeO2 were prepared with a hydrothermal procedure, which showed typical cubic CeO2 structure from Fe/Ce=1/200 to 1/10 with little fluorite structure distortion. XPS, Raman and EPR studies showed that Fe3+ doping in the CeO2 affected greatly the concentration of Ce3+. Lower doping amount of Fe3+ improved the concentration of Ce3+as well as enhanced the adsorption capacity of AO7, which resulted in better catalytic performances. Further Fe3+ doping decreased the concentration of surface Ce3+, which reduced the catalytic activity of the Fe3+ doped CeO2. FC100 of Fe/Ce=1/100 showed the maximum catalytic activity for the degradation of AO7 with H2O2. Raman and EPR studies confirmed the presence of surface peroxide species, which was derived from the complex of the surface Ce3+ and H2O2. DMPO spin trapping EPR studies indicated that peroxide species played a key role during the dark-reaction, while·OH radical induced the degradation of AO7 under visible irradiation.The amounts of both active species, were remarkably increased in the FC100-H2O2 system than those in the CeO2-H2O2 system.