Polyphenol-metal network derived nanocomposite to catalyze peroxymonosulfate decomposition for dye degradation.

Persulfate based advanced oxidation process is a promising technology for refractory contaminants removal. Cobalt is considered as the most efficient metal in catalyzing peroxymonosulfate decomposition. Although different cobalt based nanomaterials have been developed, easy aggregation and metal ion leaching during catalytic reaction would result in its deficiency. To address the above issue, in this work, carbon supported Co/CoO core-shell nanocomposite was in-situ fabricated by using polyphenol-metal coordinate as precursor. Results indicated that cobalt nanoparticle with size of 10 nm was successfully prepared and well dispersed within the carbon matrix. By using as-prepared material as catalyst, 50 mg/L orange II was completely removed under the condition of 0.2 g/L peroxymonosulfate, 0.05 g/L catalyst, pH = 4.0–10.0. Both sulfate and hydroxyl radicals were formed during peroxymonosulfate decomposition, while sulfate radical dominated the pollutant removal. Mechanism study revealed that the cobalt was the key site for catalyzing peroxymonosulfate decomposition. This work might provide valuable information in designing and fabricating metal anchored carbon composite catalyst for efficiently and cost-effectively activate peroxymonosulfate. Image 1 • Co/CoO core-shell nanostructure was well dispersed within the carbon matrix. • Co/CoO@C nanocomposite remains stable within pH ranges of 4.0-10.0, rather than the current 4.0-7.0. • Sulfate radical was the dominant reactive species for orange II removal. • Peroxymonosulfate catalytic decomposition mechanism was explored and clarified. [ABSTRACT FROM AUTHOR]