One-step preparation of Co₂V₂O₇: synthesis and application as a Fenton-like catalyst in a gas diffusion electrode

Bimetallic oxides and MOFs have been used as catalysts for the ORR via two-electron and Fenton-based processes. This work reports the development of a new green one-step route for obtaining Co₂V₂O₇. The Co₂V₂O₇ oxide was immobilized on Printex-L6 carbon and used as a catalyst for the oxygen reduction reaction (ORR) and in heterogeneous Fenton-based processes. The PL6C/2.5% Co₂V₂O₇ sample exhibited the best performance in the ORR via a two-electron pathway, increasing the selectivity for H₂O₂ generation. Electrochemical impedance spectroscopy analysis showed a decrease in charge transfer resistance in the Co₂V₂O₇/PL6C matrix. The application of a gas diffusion electrode (GDE) modified with 2.5% Co₂V₂O₇ resulted in a 30% increase in H₂O₂ production compared to the unmodified GDE. The unmodified GDE promoted methyl-paraben (MeP) removal of ∼80% after 90 min treatment, whereas the modified GDE promoted ∼90% of MeP removal in 30 min. The results obtained point to the potential of Co₂V₂O₇ in improving the efficiency of GDE when applied for the treatment of organic pollutants.