Selective O₂-to-H₂O₂ Electrosynthesis by a High-Performance, Single-Pass Electrofiltration System Using...

Area of Science:

• Materials Science and Engineering
• Environmental Chemistry
• Electrochemistry

Background:

• Producing hydrogen peroxide (H2O2) via a selective two-electron (2e) oxygen reduction reaction (ORR) is crucial for advanced oxidation processes (AOPs) in water decontamination.
• Existing methods face challenges in achieving high selectivity and cost-effectiveness for H2O2 generation.
• Carbon-based nanomaterials offer potential for catalytic applications in water treatment.

Purpose of the Study:

• To develop a highly selective 2e-ORR process for efficient H2O2 production.
• To utilize a functionalized carbon nanotube electrified membrane (IBU@CNT-EM) for ultrafast water treatment.
• To demonstrate the application of generated H2O2 in Fenton oxidation for pollutant degradation and bacterial inactivation.

Main Methods:

• Fabrication of an ibuprofen-laden carbon nanotube electrified membrane (IBU@CNT-EM).
• Ultrafast, single-pass electrofiltration process for H2O2 generation.
• Characterization of membrane performance, including H2O2 production rate and selectivity.
• Density Functional Theory (DFT) studies to elucidate the mechanism of O2 adsorption and H2O2 selectivity.

Main Results:

• Achieved a high H2O2 production rate of 25.62 mol gCNT−1 h−1 L−1 with near 2e selectivity (electron transfer number of 2.71).
• Demonstrated the efficacy of the interwoven, hydrophilic-hydrophobic membrane nanostructure for ORR acceleration.
• DFT studies confirmed enhanced O2 adsorption and intermediate stability on IBU@CNT, correlating with high H2O2 selectivity (64.39%).
• The generated H2O2 effectively decomposed emerging pollutants and inactivated bacteria via Fenton oxidation.

Conclusions:

• The IBU@CNT-EM electrofiltration process provides a simple, durable, and highly efficient method for H2O2 production.
• This technology presents a new paradigm for developing high-performance H2O2-production membranes for cost-effective water treatment.
• Reusing environmental functional materials like ibuprofen offers a sustainable approach for advanced water decontamination.