The enhanced Fenton-like catalytic performance of PdO/CeO2 for the degradation of acid orange 7 and salicylic acid

Abstract

A PdO/CeO2 catalyst was prepared by deposition-precipitation method and characterized with X-ray diffraction, high-resolution transmission electron microscopy, N2 adsorption-desorption, X-ray photoelectron spectroscopy and Raman spectroscopy. The results show that the Pd is presented as Pd2+ in the catalyst. The interaction between the deposited PdO and CeO2 increases the Ce3+ content. The catalytic activity of PdO/CeO2 was tested in the heterogeneous Fenton-like degradation of acid orange 7 (AO7) and salicylic acid (SA), both in the dark and under visible irradiation. Deposition of PdO accelerates the Fenton-like degradation of SA, which reaches a maximum at 1.0 atom% PdO loading. A dye sensitization effect was seen with AO7 under visible irradiation. Dye sensitization promotes the regeneration of Ce3+ by interfacial peroxides species through interfacial electron injection. Consequently, the combined effects of PdO loading and visible light irradiating enhanced the Fenton-like activity to a reaction rate constant of 3.90 h−1 for the 1.0 PdO/CeO2, a ca. 50-fold improvement.