Polarization-Switchable Electrochemistry of 2D Layered Bi₂O₂Se Bifunctional Microreactors by Ferroelectric Modulation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ferroelectric materials alter catalytic activity through polarization.
• Controlling polarization direction is key to tuning surface reactions.

Purpose of the Study:

• To demonstrate polarization-switchable electrochemistry using layered bismuth oxyselenide (L-Bi2O2Se) bifunctional microreactors.
• To achieve selective control over oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) using ferroelectric modulation.

Main Methods:

• Developed selective-area ionic liquid gating for precise control of L-Bi2O2Se dipole orientation.
• Fabricated on-chip microreactors with upward and downward polarization.
• Utilized nanoscale scanning electrochemical cell microscopy to investigate reaction mechanisms.

Main Results:

• Upward polarized microreactors favored the oxygen evolution reaction (OER).
• Downward polarized microreactors preferred the hydrogen evolution reaction (HER).
• Demonstrated overall water splitting using a full-cell configuration with bifunctional L-Bi2O2Se catalysts.

Conclusions:

• Ferroelectric polarization switching in L-Bi2O2Se enables switchable electrochemistry.
• Enhanced surface adsorption and reduced energy barriers are the origins of this effect.
• This approach offers a new pathway for designing advanced catalysts for water splitting.