Activation of peroxydisulfate by Ce-doped Cu-Fe@γ-Al2O3 microspheres for polyvinyl alcohol, Reactive Red X-3B, and Rhodamine-B degradation

Abstract

Advanced oxidation processes based on copper-iron bimetallic activated peroxydisulfate (PDS) can degrade pollutants, but the catalytic activation of PDS by copper-iron bimetallic catalysts can be further improved. In this work, Ce-doped Cu-Fe@γ-Al2O3 microspheres were fabricated and used to degrade polyvinyl alcohol (PVA). Contrast experiments showed that the Ce-doped Cu-Fe@γ-Al2O3/PDS system degraded 100 % of PVA after 180 s treatment at pH 7, a Ce(NO3)4·6H2O dosage of 15 %, a catalyst dosage of 1.25 g/L, a reaction temperature of 60 °C, and a PDS dosage of 2 g/L. Experiments showed that adding Ce atoms enhanced the stability and reusability of the catalyst containing copper and iron. In addition, the Cu-Fe@γ-Al2O3/PDS system showed degraded 99.98 % of Rhodamine-B and 99.96 % of Reactive Red X-3B dyes. EPR results showed that SO4·-, ·OH, O2·-, and 1O2 radicals were responsible for the degradation of PVA, Reactive Red X-3B, and Rhodamine-B. This study clarified the interaction mechanism between Ce, Cu, and Fe in the Cu-Fe@γ-Al2O3/PDS system. Our study provides guidance for improving the activation efficiency of PDS by Cu-Fe catalysts.