Synergistic degradation of phenols by bimetallic CuO–Co3O4@γ-Al2O3 catalyst in H2O2/HCO3− system

Abstract

The development of new catalytic techniques for wastewater treatment has long attracted much attention from industrial and academic communities. However, because of catalyst leaching during degradation, catalysts can be short lived, and therefore expensive, and unsuitable for use in wastewater treatment. In this work, we developed a bimetallic CuO–Co3O4@γ-Al2O3 catalyst for phenol degradation with bicarbonate-activated H2O2. The weakly basic environment provided by the bicarbonate buffer greatly suppresses leaching of active Cu and Co metal ions from the catalyst. X-ray diffraction and X-ray photoelectron spectroscopy results showed interactions between Cu and Co ions in the CuO–Co3O4@γ-Al2O3 catalyst, and these improve the catalytic activity in phenol degradation. Mechanistic studies using different radical scavengers showed that superoxide and hydroxyl radicals both played significant roles in phenol degradation, whereas singlet oxygen was less important.