Vanadium as co-catalyst for exceptionally boosted Fenton and Fenton-like oxidation: Vanadium species mediated direct and indirect routes.

In this study, vanadium powder (V) was employed as a cocatalyst to enhance the Fenton-like system. The V-Fe(III)/H ₂ O ₂ system can rapidly produce hydroxyl radicals and completely oxidize chloramphenicol with exceptionally high stability for long-term operation. The low-valent vanadium sites on the surface during the stepwise oxidation of vanadium from V ⁰ to V(IV) can donate electrons for direct H ₂ O ₂ activation and indirect Fenton reaction by reducing Fe(III) to produce hydroxyl radicals. Meanwhile, density functional theory (DFT) calculation unveils that low-valent vanadium sites of vanadium can lengthen Fe-O bonds of FeOH ²⁺ to elevate the oxidation potential of Fe(III) and promote Fe(III) reduction induced by H ₂ O ₂ . The self-cleaning effect of vanadium under acidic conditions can maintain reactive sites for sustainable electron donation and long-lasting enhanced Fenton oxidation. This study provides a novel enhanced Fenton oxidation for water remediation and the first mechanistic insights into the origins of V-based advanced oxidation technologies, it may also be beneficial to treat vanadium-contained wastewater.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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