Advanced oxidation processes at water/hydrophobic interfaces: energy-fluctuation mechanism and electron utilization...

Area of Science:

• Physical Chemistry
• Surface Science
• Electrochemistry

Background:

• The driving force behind water/hydrophobic interface chemistry is debated, with contact-electro-catalysis (CEC) offering a new perspective via mechanical energy conversion.
• Ultrasonication studies have raised questions about CEC reaction mechanisms, lacking quantitative energy-to-electron conversion assessments.

Purpose of the Study:

• Investigate radical-mediated advanced oxidation processes (AOPs) at water/hydrophobic interfaces without high energy input.
• Elucidate the mechanism of interfacial water polarization and its role in driving reactions.
• Develop a framework to quantify electron utilization efficiency in CEC.

Main Methods:

• Theoretical analysis of flexoelectric effects at the water/hydrophobic interface.
• Experimental investigation of AOPs using a quantifiable press-and-release device.
• Evaluation of triboelectric electron utilization ratio in CEC.

Main Results:

• Flexoelectric response of interfacial water generates a polarization field, enabling electron separation from H2O or OH-.
• Interfacial energy fluctuations are identified as the primary reaction driving force.
• A methodology for evaluating CEC electron utilization yielded an estimated efficiency of ~44.8%.

Conclusions:

• Flexoelectricity is proposed as the key mechanism driving AOPs at water/hydrophobic interfaces.
• The study establishes a quantifiable framework for assessing CEC efficiency.
• This work provides insights into interfacial AOPs, contact electrification, and offers a sustainable approach for water purification and pollutant degradation.