Effect of nanosized CeO2 or ZnO loading on adsorption and catalytic properties of activated carbon

Abstract

Activated carbon (AC) prepared from activation of ground peach stones with phosphoric acid under flowing air was used as a support for CeO2 and ZnO nanoparticles through hydrothermal method at 200℃ for 120 min and followed by the calcination at 400℃ for 180 min. The produced samples were named as AC, CeO2–AC, and ZnO–AC, respectively. The characterization of samples was made by means of scanning electron microscope, energy dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area. A remarkable impact on the surface, structural, and textural properties of AC support was obtained as a result of loading for CeO2 or ZnO. Results of X-ray diffraction showed that nanocrystallines CeO2 and ZnO phases on the AC support were formed. Removal efficiency of the prepared samples was investigated through adsorption, photodegradation, and wet peroxide oxidation processes using Maxilon Red basic dye (MR). Accordingly, the prepared samples exhibited different removal behaviors towards MR dye depending on the total surface area and type of catalyst; for example, the maximum removal of MR dye was found in the following orders: AC > ZnO-AC > CeO2-AC, CeO2-AC > ZnO-AC > AC, and AC > CeO2-AC > ZnO-AC via adsorption, photodegradation, and catalytic oxidation with H2O2, respectively. It was found that photodegradation process was the best when compared with the other methods. The photocatalytic activity of CeO2-AC catalyst was the highest. The reusability tests showed that CeO2-AC exhibited superior photocatalytic performance and stability till the fourth run as compared to photocatalytic activity of ZnO-AC which decreased from 90% to 78% in the fourth run. Therefore, the prepared CeO2-AC catalyst is more effective than ZnO-AC as confirmed by reusability tests.