Enhanced Peroxymonosulfate Activation by Δ-Mno2 Nanocatalyst Enriched with Oxygen Vacancies for Phenolic Pollutants Polymerization

Heterogeneous advanced oxidation processes technology holds great potential for the removal of toxic phenolic molecules, but is challenged by overuse of oxidation agent and undesirable carbon emission. This work demonstrates that Fe doped δ-phase MnO2 (δ-MnO2) served as nanocatalyst, and the phenolic pollutants (PhOH) could be removed with high selectivity and effective conversion into non-toxic phenolic polymers via an electron transfer route. Fe doping promoted the production of oxygen vacancies, improving the activation of peroxymonosulfate (PMS) by extending the length of O-O bond. A 6.68-fold enhancement of the removal rate of PhOH was achieved by Fe-MnO2, comparing to pristine δ-MnO2. Moreover, the consumption of PMS could be saved up to 95.08 %, and the carbon emission was also reduced by 99.13 %. This work manifests electron transfer route offers significant potential for the cost-effective use of oxidation agent and low carbon emission for achieving carbon neutral in environmental remediation.