"d-electron interactions" induced CoV₂O₆-Fe-NF for efficient oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing cost-effective, efficient, and eco-friendly non-noble metal electrocatalysts is crucial for oxygen evolution reactions (OER).
• Cobalt vanadate (CoV2O6) on nickel foam (NF) serves as a promising base material.

Purpose of the Study:

• To synthesize and evaluate a novel electrocatalyst, CoV2O6-Fe-NF, for enhanced OER performance.
• To investigate the role of iron (Fe) incorporation in improving the catalytic activity of CoV2O6.

Main Methods:

• Synthesis of CoV2O6 on nickel foam (NF).
• Introduction of Fe2+ via Fe3+ immersion treatment to create CoV2O6-Fe-NF.
• Characterization using in situ Raman spectroscopy.
• Electrochemical testing of OER performance in 1 M KOH.

Main Results:

• Fe2+ transforms into a higher oxidation state Fe species due to transition metal 3d electron interactions.
• The Fe-modified catalyst (CoV2O6-Fe-NF) exhibits a lower overpotential (298 mV at 100 mA cm-2) compared to unmodified CoV2O6-NF (348 mV).
• In situ Raman spectroscopy elucidated the OER mechanism in the presence of Fe, highlighting increased active sites.

Conclusions:

• The synergistic effect of transition metal 3d electrons and the higher oxidation state of Fe significantly enhances OER efficiency.
• CoV2O6-Fe-NF presents a highly efficient and potentially cost-effective electrocatalyst for OER.
• This work provides valuable insights for designing advanced transition metal electrocatalysts.