A polyphenol-engineered interfacial framework enables aeration-free electro-Fenton via localized oxygen enrichment

Area of Science:

• Environmental Chemistry
• Electrochemistry
• Materials Science

Background:

• The electro-Fenton (EF) process for antibiotic degradation is limited by poor dissolved oxygen mass transfer, necessitating inefficient aeration.
• Existing methods struggle with oxygen supply, hindering practical application and overall efficiency.

Purpose of the Study:

• To overcome oxygen mass transfer limitations in EF processes for antibiotic degradation.
• To develop a novel strategy for localized oxygen enrichment at the cathode surface.
• To enhance in situ hydrogen peroxide generation and pollutant oxidation efficiency.

Main Methods:

• Fabrication of a tannic acid (TA)-modified electrode (TPC) via molecular self-assembly.
• Investigation of the electrode's oxygen affinity and selective 2e- oxygen reduction reaction (ORR).
• Evaluation of hydrogen peroxide yield, oxygen utilization efficiency (OUE), and electrochemical durability.
• Assessment of sulfathiazole degradation efficiency and kinetic analysis.
• Characterization using spectroscopy, structural analysis, and DFT calculations.

Main Results:

• The TPC electrode achieved a high H2O2 yield (25.5 mg L-1) and OUE (33.88%) without aeration.
• Demonstrated excellent electrochemical durability and stable H2O2 production over multiple cycles.
• Achieved complete sulfathiazole degradation within 120 min, with a 2.9-fold higher rate constant than the unmodified electrode.
• Confirmed TA-induced redox-active interface regions accelerating reactive oxygen species (ROS) generation.

Conclusions:

• The localized oxygen enrichment framework effectively enhances EF process performance by creating an oxygen-rich microenvironment.
• The TA-modified electrode offers a sustainable and efficient solution for electrochemical antibiotic degradation.
• This approach presents a promising pathway for developing advanced electrochemical water treatment technologies.