Molecular oxygen activation by MnOx-anchored aluminum-graphite for micropollutants degradation at near-neutral conditions

Abstract

Activating molecular oxygen (O2) to produce short-lived reactive species (RSs) remains a major challenge at neutral pH conditions. Herein, a novel MnOx-anchored aluminum-graphite material (MnOx-Al-Gr) was successfully synthesized, which could be used for O2 activation without external energy. In the MnOx-Al-Gr/O2 process, O2 was first reduced to hydrogen peroxide (H2O2) by electrode reaction on the Al//Gr corrosion cells in MnOx-Al-Gr, and the generated H2O2 could be subsequently decomposed by the surface Mn species. MnOx on the Al-Gr composites surface decreased the charge transfer resistance and promoted the generation of short-lived RSs including H*, 1O2 and O2•−, which could be well used for water decontamination. Highly efficient removal (>90%) of tetracycline (TC) was achieved at pH 5–7; 1O2, H* and the surface Mn species were responsible for the TC degradation. This study developed a cheap and energy-free O2 activator for RSs generation and achieved micropollutants degradation at near-neutral pH conditions.