Short-Ligand Modification in CsPbBr₃ Perovskite Quantum Dots for Improved Photoelectrocatalytic Properties

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Photoelectrochemical cells (PECs) using CsPbBr3 quantum dots (QDs) show promise for water splitting.
• Long-chain ligands on QDs hinder photogenerated carrier separation and transfer, limiting performance.

Purpose of the Study:

• To enhance the efficiency and stability of CsPbBr3 QD-based photoanodes for water splitting.
• To investigate the impact of ligand exchange on carrier dynamics and device performance.

Main Methods:

• Solid-state ligand exchange on CsPbBr3 QDs, replacing oleic acid (OA) with 3-mercaptopropionic acid (MPA).
• Fabrication of MPA-CsPbBr3 QDs photoanodes.
• Performance evaluation under simulated sunlight irradiation, including photocurrent density and long-term stability tests.

Main Results:

• MPA ligand exchange reduced grain spacing and passivated surface defects.
• MPA-CsPbBr3 QDs exhibited lower resistance and improved stability.
• Achieved a photocurrent density of 4.23 mA cm-2 with sustained stability over 11,600 seconds.

Conclusions:

• Short-chain ligand exchange is an effective strategy to improve CsPbBr3 QD photoanode performance.
• The modified QDs demonstrate superior carrier separation, transport, and durability for photoelectrocatalytic water splitting.
• This work offers valuable insights for developing advanced perovskite QD-based photoelectrocatalysts.