Visualization of aquaionic splitting via iron corrosion

Area of Science:

• Electrochemistry
• Materials Science
• Physical Chemistry

Background:

• Iron corrosion in aqueous solutions is a well-studied phenomenon.
• Controlling electrochemical reactions on metal surfaces is crucial for various applications.
• Understanding ion transport in aqueous media is fundamental to chemical processes.

Purpose of the Study:

• To report and investigate a novel water decomposition mode termed Aquaionic Splitting (AiS) driven by iron corrosion.
• To demonstrate selective separation of water into protons and hydroxide ions through controlled corrosion.
• To quantify proton diffusion during the AiS process.

Main Methods:

• Controlled iron corrosion in aqueous solution using a pseudo-sacrificial protection method with oil paint.
• Visualization of aquaion distribution using BTB solution, a pH-sensitive indicator.
• Estimation of proton diffusion coefficient via colorimetric analysis of BTB solution patterns.
• Computer simulation of aquaion distribution by solving the diffusion equation.

Main Results:

• Demonstrated a controllable water decomposition process (Aquaionic Splitting) initiated by iron corrosion.
• Successfully visualized the spatial distribution of aquaions (protons and hydroxide ions) using pH-dependent color changes.
• Quantified the diffusion coefficient of protons based on observed color patterns.
• Computer simulations validated the experimental findings on aquaion distribution.

Conclusions:

• Iron corrosion can be harnessed to achieve selective water splitting into protons and hydroxide ions.
• The AiS process offers a new pathway for water decomposition with potential applications in chemical synthesis and energy.
• The study provides a method for visualizing and quantifying ion dynamics during electrochemical processes.