FeNiCeOx ternary catalyst prepared by ultrasonic impregnation method for diclofenac removal in Fenton-like system

FeNiCeO x was firstly prepared by ultrasonic impregnation method and used to remove diclofenac in a Fenton-like system. The catalytic activity was improved successfully by doping Ni into FeCeO x . The diclofenac removal efficiency reached 97.9% after 30 min reaction. The surface morphology and properties of FeNiCeO x were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Raman and X-ray photoelectron spectroscopy (XPS) analyses. FeNiCeO x in this paper had larger specific surface area than those prepared by other methods, which was attributed to the cavitation effect and hot-spot effect during the ultrasonic synthesis process. Low crystallinity of Fe 2 O 3 and NiO showed by characterization could lead to high interaction of Fe and Ni ions with support of CeO 2 . They substituted Ce in CeO 2 , caused lattice contraction and formed more oxygen vacancies, which favoured the catalytic reaction. Meanwhile, Fe and Ce ions both had redox cycles of Fe 3+ /Fe 2+ and Ce 4+ /Ce 3+ , which facilitated the electron transfer in the reaction. The synergistic effect among Fe, Ni and Ce might lead to better catalytic performance of FeNiCeO x han any binary metal oxides constituted from the above three elements. Finally, the potential mechanism of diclofenac removal in FeNiCeO x -H 2 O 2 system is proposed.